Month: June 2023

We examine how the last three recessions affected hourly earnings, the probability of receiving a bonus, and weekly hours in agricultural labor market. We compare those results to those in three non-agricultural labor markets that rely on immigrants. We empirically test five hypotheses. first, we expect seasonal agricultural workers’ earnings to rise during major recessions. Because the income elasticities of demand for seasonal agricultural products such as fruits and vegetables are relatively inelastic, recessions cause a small, possibly negligible leftward shift of the labor demand curve in seasonal agriculture. In contrast, a recession’s may cause a significant leftward shift of the labor supply curve. Roughly half of hired, seasonal agricultural workers are undocumented.The Great Recession significantly reduced the number of new, undocumented immigrants entering the United States , causing a substantial leftward shift of the agricultural labor supply curve.Given a substantial leftward shift of the supply curve and only a minimal shift of the demand curve, agricultural workers’ earnings rise. Second, while we hypothesize that hourly earnings and the probability of receiving a bonus rose during the Great Recession, 2008–2009, we expect these earnings measures to rise by less or possibly fall in the earlier,drainage planter pot relatively minor 1990–1991 and 2001 recessions. The Great Recession caused much larger decreases in new immigrant labor supply than in these earlier recessions . Third, we expect recessions to affect undocumented workers differently than documented workers because their labor markets are partially segmented.

Evidence that these markets are partially segmented comes from earlier studies that show that, compared to documented workers, undocumented workers are more likely to be employed by farm labor contractors as opposed to farmers, and because their pay differs . Fourth, we expect weekly hours of employed agricultural workers to increase to compensate for the reduced flow of new immigrants during major recessions. Fifth, we expect recessions to have larger earnings effects in agricultural labor markets than in construction, hotel, and restaurant labor markets. These non-agricultural labor markets are more likely to have sticky wages due to union and other contracts and minimum wage laws. The first section discusses how recessions affect the supply curve of agricultural labor. The next section describes our two data sets. The third section presents our empirical results. The final section discusses our results and draws conclusions.In contrast, during a major recession, fewer undocumented immigrants enter the United States from Mexico and other countries. Passel, Cohn and Gonzalez-Barrera reported a large drop in the number of undocumented immigrants during the Great Recession relative to the recovery years afterward and to preceding years, which include milder recessions. They estimated that the number of undocumented immigrants rose monotonically from only 3.5 million in 1990 until it peaked at 12.2 million in 2007. However, the number of immigrants fell to 11.3 million by 2009 during the Great Recession. In contrast, they found that the supply of immigrant labor rose during relatively mild 2001 recession.These results are consistent with U.S. border patrol reports from the Department of Homeland Security’s Office of Immigration Statistics. Apprehensions by the U.S. border patrols dropped from 876,803 in 2007 to 556,032 in 2009. Because immigrants often send money home, we can use remittances from the United States to Mexico to infer whether the number of immigrants changed substantially during a recession. Figure 2 shows quarterly remittances to Mexico in millions of U.S. dollars as reported by Banco de México .

The figure shows that remittances increased during the relatively mild 2001 recession but decreased substantially during the 2008–2009 Great Recession. These data again support the view that the number of Mexican immigrants to the United States fell during the Great Recession but not during the previous, milder recession. Moreover, Warren and Warren estimated that the net change of undocumented immigrants was negative during the Great Recession, which was related to a sharp decrease of new undocumented immigrants. The United States Department of Agriculture, Economic Research Service estimated number of full- and part-time agricultural workers fell from 1.032 million in 2007 to 1.003 million in 2008 and 1.020 million in 2009, before rising to 1.053 million in 2010.5 That is, the number of workers in 2008 was 3% to 5% lower than in the years before and after the Great Recession. Presumably the share of workers dropped by even more in seasonal agriculture, which employs most of the undocumented workers.The NAWS is an employer-based survey. That is, it samples worksites rather than residences to overcome the difficulty of reaching migrant farm workers in unconventional living quarters. These employers are chosen randomly within the U.S. Department of Agriculture’s 12 agricultural regions .Surveyors randomly select 2,500 employees of these growers to obtain a nationally representative sample of crop workers. Surveyors interview the more than 2,500 crop workers outside of work hours at their homes or at other locations selected by the respondent. The NAWS has a long, visible history within farming communities, and the survey design incorporates questions aimed at data validation about legal status.As a result, only one to two percent of workers in the overall sample refuse to answer the legal status questions. The NAWS contains extensive information about a worker’s compensation, hours worked, and demographic characteristics such as legal status, education, family size and composition, and workers’ migration decisions. We dropped workers from the sample who were missing any relevant variable, 23% of the original survey sample.

The NAWS is conducted in three cycles each year year to match the seasonal fluctuations in the agricultural workforce. Unfortunately, the public-use data,which we use, suppresses information about the cycle and aggregates the 12 regions into 6 regions. As a result, our data set consists of repeated annual cross sections of workers from 1989 through 2012. Column 1 of Table 1 presents national summary statistics for the variables used in our empirical analysis. Columns 2 and 3 provide data for California and for the rest of the country, because 37% of the sample works in California. Compared to workers in the rest of the country,plant pot with drainage Californian workers tend to have less education; have more farm experience; are more likely to be non-native, Hispanics; and are more likely to work in fruit and nut crops and less likely to work in horticulture. After analyzing the effects of recessions on agricultural workers, we replicate the analysis for workers in construction, hotels, and restaurants, which also employ many immigrants. The data for workers in these sectors come from the March Current Population Survey . In March of each year, workers in the basic CPS sample are administered a supplemental questionnaire in which they are asked to report their income such as hourly wage rate and additional labor force activity such as hours worked in the previous week.8 Because information on immigration is available only since 1994, our sample period is 1994–2013. We include all workers who are 18 years and older.Three recessions occurred during our 1989–2012 sample period . The economy recovered quickly from the first of these recessions in 1990–1991. The second, 2001 recession was also relatively mild. However, the third recession, the 2008–2009 Great Recession, was much more severe and had longer-lasting economic and labor market effects than the first two. We analyze the effects of recessions on hourly earnings, the probability of receiving a bonus, and weekly hours of work of employed workers. For workers paid by time, hourly earnings are a worker’s hourly wage. For piece-rate workers, we use the workers’ reported average hourly earnings. The bonus dummy equals one for workers who receive a money bonus from an employer in addition to the wage, and zero otherwise. Weekly hours of work are the number of hours interviewees reported work at their current farm job in the previous week. The explanatory variables in all these equations are the same. The explanatory variables include all the usual demographic variables: age, years of education, years of farm experience, job tenure , gender, whether the workers is Hispanic, whether the worker was born in the United States, and whether the worker speaks English.The specification uses a legal status variable to capture the bifurcated labor markets for documented and undocumented workers. It also includes crop and regional dummies.

We have seven main explanatory variables: dummies for each of the three recessions, the recession dummies interacted with the legal status dummy , and regional unemployment rates for workers in all sectors of the economy. We use separate dummies for each recession to allow for differential effects across the recession . The interaction terms capture whether employers treat undocumented workers differently than legal workers during a recession. We include the unemployment rate because it peaks after the end of each recession . We do not report the unemployment rate interacted with the undocumented dummy because we cannot reject that its coefficient is zero in any equation. We treat all these variables as exogenous to the compensation and weekly hours of individual agricultural workers. We start by examining the effects of recessions on NAWS workers’ hourly earnings. Column 1 of Table 2 presents regression estimates for the ln hourly earnings equation. The coefficients on the demographic variables have the expected signs and are generally statistically significantly different from zero at the 5% level. Undocumented workers’ hourly earnings are 2.1% less than those of documented workers. Females earn 6.4% less than males. Hispanics earn 4.9% less than nonHispanics. Unlike most previous studies, we find a statistically significant effect of education. English speakers earn 3.9% more than non-English speakers. The coefficients on the recession dummies reflect the effect of the recession on documented workers. Documented workers’ hourly earnings rose 1.8% during the 1990–1991 recession, 4.2% during the 2001 recession, and 6.9% during the Great Recession. We draw two conclusions about the effects of recessions on documented workers. first, the hourly earning effect of the Great Recession was larger than that of the relatively minor recessions, which is consistent with literature on business cycles and the farm labor market in the 1970s . Second, in all recessions, documented workers’ wages rose, which suggests that recessions cause the hired-agricultural-worker supply curve to shift leftward relatively more than did the demand curve. The sum of the coefficients on the recession dummy and its interaction with the undocumented dummy captures the effect of a recession on undocumented workers. The 1990–1991 recession did not have a statistically significant effect on undocumented workers. Hourly earnings for undocumented workers rose by 3.4% during the 2001 recession and 1.9% during the Great Recession. In contrast to the pattern for documented workers, the undocumented workers’ earnings rose by less during the Great Recession than during the 2001 recession. Thus, not only do undocumented workers earn less than documented workers do in general, but their hourly earnings rise less during recession than do the earnings of documented workers. That is, the wage gap between documented and undocumented workers widens during recessions. In addition to hourly earnings, 28% of the workers in our sample receive bonus payments , which supplement relatively low wage payments . These deferred payments play a similar function to that of efficiency wages in other sectors . We use a binary indicator equal to one if a worker receives a money bonus. Column 2 of Table 2 shows the results of a regression using a linear probability model . For documented workers, the probability of receiving a bonus did not rise during the two relatively minor recessions but increased by 5.8 percentage points during the Great Recession. Thus, the Great Recession not only raised documented workers’ hourly earnings, but it raised the probability that they received a bonus substantially. For undocumented workers, the probability of receiving a bonus fell by 2.9 percentage points during the 1990–1991 recession and rose by 9 percentage points during the Great Recession. Again, this result is consistent with the theory that the Great Recession caused a large supply side shock. Thus, for both documented and undocumented workers, the Great Recession had a larger, positive effect on the probability of receiving a bonus than did earlier recessions. The unemployment rate has a statistically significant effect on the probability of receiving a bonus payment.

The role of Pv08 in the original domestication of Middle American common beans also cannot yet be ruled out. Our Pv03 QTL mapping peak in the MxB population was closer in physical distance to PvPdh1 than what has been previously identified through QTL mapping in a different recombinant inbred population—ICA Bunsi x SXB405 . These results are still not as close to the gene as those achieved by GWAS with a much larger SNP dataset . The correlation between PvPdh1 allele and pod twists indicates that the gene may modify the twisting force of pod walls. This has been seen in the soybean ortholog as well as across numerous legume species . The complex dominance of PvPdh1-mediated shattering resistance parallels the pattern seen in soybean pods, in which the phenotyping method affects the pattern of dominance . The desiccation method was faster to phenotype than counting pod twists and also produced results which were much more correlated with genotype. This indicates that the desiccator method may be a more effective method of phenotypic screening than counting twists. The recessive nature of pod shattering when phenotyped by the desiccator method means that carriers of the resistant Pvpdh1 allele may demonstrate high levels of pod shattering in early breeding program generations because of heterozygosity and should not be eliminated without direct genetic evaluation or subsequent progeny tests. Further,how to set up a vertical farm the recessive nature of shattering resistance when phenotyped by the desiccator method also indicates that recurrent back crossing based on phenotyping alone would not be practical for the trait.

Pvpdh1 therefore requires a genetic marker for screening of progenies that carry the shattering-resistance allele.Our results indicate that durable resistance to pod shattering has evolved independently in both the Middle American and Andean gene pools of common bean. Despite this, many varieties in both gene pools continue to display the wild type propensity to shattering, and this is strongly associated with market class. Our results agree with earlier anecdotal observations that pod shattering is most problematic in the black and cranberry market classes , the two categories with the highest rates of pod shattering in the MDP and ADP. In contrast, market classes with the lowest rates of pod shattering are those in which the resistant Pvpdh1 allele is most abundant . While direct comparisons between the Andean and Middle American gene pools are complicated by the fact that the populations were grown in different years, the desiccation treatment used to induce pod fracture was identical between populations. In any case, it is clear that many varieties of both gene pools experience high levels of pod shattering and would benefit from the introgression of shattering-resistance alleles. Market demands require most new varieties of common bean to conform to standards for several complex traits, such as seed size, shape, color, leading most modern breeding to focus preferentially on intra-race crosses. Marker assisted back crossing would greatly facilitate the transfer of the shattering-resistant allele into other ecogeographic races, while maintaining the complex genetic background required in a market class. A better understanding of the PvPdh1 locus, as well as molecular markers associated with it, will become increasingly important for crop improvement as conditions become more arid in the twenty-first century.Our haplotype diversity results are consistent with the hypothesis that there has been stronger selection pressure on PvPdh1 in race Durango than in race Mesoamerica.

After selection of the shattering resistant allele at PvPdh1, race Durango types differentiated into just two additional new haplotypes, which represent 3% of the group’s sampled varieties. The non-shattering character found in the low-frequency haplotypes indicates that these groups may have differentiated since the mutation in PvPdh1, rather than being ancestral reflicts of a shattering-susceptible race Durango progenitor. In contrast, race Mesoamerica includes six total haplotypes, and the ive least common of these together represent 7% of the sampled varieties. This is more than double the frequency of minor haplotypes than in race Durango. These less-common variants could be the subject of future study to identify whether secondary mutations in PvPdh1 have independently arisen to regulate pod shattering in a subset of varieties within race Mesoamerica.While EcoRI is a highly stable, robust enzyme, TaqII is a high molecular weight, lower-stability enzyme, which requires highly specific conditions for optimal DNA cleavage . This includes a predigestion PCR product cleanup and extreme care in handling of the enzyme. Although TaqII treatment always led to digestion of susceptible alleles, this digestion was sometimes only partial, leading to ambiguity between homozygous susceptible and heterozygous individuals. Further, the cleavage of shattering-susceptible alleles is generally less desirable than cleavage of resistant alleles to reduce the risk of selecting susceptible types due to technical errors. While the TaqII-based marker may be ideal for initial parental screening, the tightly linked EcoRI-based CAPS marker may be more practical for rapid, efficient screening of large breeding populations. The CAPS markers developed here may be valuable for rapidly transferring the pod-shattering resistance of race Durango into the market classes of race Mesoamerica and the Andean gene pool. Pod shattering is a complex quantitative trait and is regulated by multiple alleles and environmental variables. Indeed, selection based on phenotyping alone will not always be predictive of an individual’s susceptibility to pod shattering , leading to imperfect selection accuracy.

Our CAPS markers will provide a more accurate and rapid method to genetically evaluate an individual’s resistance to pod shattering. Similarly, the SNPs used to develop these CAPS markers could be converted to Kompetitive Allele specific PCR markers through commercially available services. Phenotypically, this trait cannot be measured until after plants have fully senesced, delaying selection and requiring breeders to invest heavily in non-desired plants. Further, it often requires additional heat treatment incubation periods or labor-intensive analyses with specialized equipment, such as mechanical force measurement gauges, to study accurately . In contrast, our genetic tests can be conducted rapidly on segregating populations of seedlings, reducing costs for breeding programs and hastening genetic improvement. These markers will also allow breeders to accurately pyramid shattering resistance alleles from the Andean and Middle American gene pools for the first time, potentially leading to stronger resistance to pod shattering than what is provided by Pvpdh1 alone. In turn, this will facilitate the development of varieties that are more tolerant of warm, dry environmental conditions where pod shattering is most problematic.Tolerance to desiccation can be defined as the ability of an organism to survive extreme dehydration and then to resume normal growth upon rehydration.Vascular plants with the ability to revive from extreme desiccation are commonly called as resurrection plants.3 To date, more than 300 angiosperms,what is vertical growing including a few dicotyledonous plants, have been identified as resurrection plants.Tolerance to desiccation in resurrection plants is a complex process that involves many physiological and metabolic mechanisms.The strategies adopted by resurrection plants to survive desiccation may resemble those seen in seeds.Water deficit is initially accompanied by osmotic adjustment to protect against cellular damage, which is accomplished by the accumulation of large amounts of sugars, amino acids, and small polypeptides such as late embryogenesis abundant proteins and dehydrins. Increasing water deficit results in the activation of mechanisms to cope with desiccation-induced structural and functional alterations of macromolecules and membranes, the accumulation of toxic substances and free radicals, and mechanical damage associated with the loss of turgor.Under desiccation stress, the oxidative damage caused by the production of reactive oxygen species is enhanced, especially in chloroplasts. Two different strategies are adopted by resurrection plants to minimize ROS damage. Homoiochlorophyllous resurrection plants conserve the structure of their photosynthetic apparatus, synthesize anthocyanins, and increase the activity of antioxidants during desiccation, whereas poikilochlorophyllous resurrection plants demolish chloroplast pigments and membranes, thus reducing cellular sources of ROS.6 Resurrection plants are excellent models for studying molecular mechanisms that could potentially serve as biotechnological tools for enhancing drought tolerance.There have been many studies of the molecular effects of drought on model plants such as Arabidopsis and rice,but information is scarce on the desiccation tolerance mechanisms of resurrection plants.Transcriptomics has been used to generate global gene expression atlases, such as for powdery mildew resistance,horticultural traits in apple,fruit ripening, and cherry fruit development.To understand desiccation tolerance mechanisms, transcriptomic and proteomic studies have been performed in resurrection plants such as Sporobolus stapfianus, Tortula ruralis, Xerophyta viscosa,and Boea hygrometrica.However, large-scale expressed sequence tag sequencing analysis using high-throughput sequencing and de novo assembly strategies have only been conducted in two herbaceous species, Craterostigma plantagineum and Haberlea rhodopensis.

Myrothamnus flabellifolia, a woody homoiochlorophyllous resurrection plant growing in the mountainous regions of central and southern Africa,is probably the most primitive angiosperm to show extreme tolerance to desiccation.It displays novel anatomical, ultra-structural, and biochemical adaptations to desiccation stress and has been the subject of a number of physiological and biochemical studies. Under severe drought conditions, M. flabellifolia leaves can become air-dry, folding in a unique fan-like manner.Upon rewatering, the leaves return to their original color and shape within 24 hours.Biochemical studies of the cell walls have demonstrated an abundance of arabinose polymer side chains, consisting of arabinans associated with the pectin matrix, which may explain the flexibility of the mesophyll cells, allowing leaf morphology to be rapidly recovered after rehydration.During desiccation, presumably to protect from ROS, the leaves synthesize large amounts of anthocyanins and change their color from green to dull-brown.High levels of phenols, including tannins, arbutin, and tri-O-galloylquinic acid, have been reported in the leaves of M. flabellifolia. Differences in phenolic content and composition may be associated with differences in tolerance to desiccation stress among populations of M. flabellifolia.Moreover, desiccated leaves of M. flabellifolia contain high levels of saccharides, although the precise constituents differ.The molecular mechanisms underlying the tolerance of M. flabellifolia and its ability to rapidly rehydrate are still largely unknown. In the present work, we attempt to investigate the transcriptome dynamics in response to dehydration and rehydration in M. flabellifolia. Most woody fruit and ornamental plants can encounter extreme drought stress. Therefore, understanding this plant’s extreme tolerance to desiccation and drought can aid the development of strategies for improving drought stress resistance in horticultural crops.To evaluate the potential functions of genes that showed significant transcriptional changes during dehydration and rehydration in M. flabellifolia, we examined the GO enrichment of DTGs at each dehydration and rehydration stage. The biological processes that were significantly enriched early in dehydration included many defense responses such as response to chitin, cold, wounding, and fungi . This is consistent with a previous transcriptomic study in the resurrection plant H. rhodopensis in which many genes involved in acquiring tolerance to a variety of abiotic and biotic stresses were induced by desiccation stress.In striking contrast, the DTGs represented in moderately dehydrated and desiccated leaves participate in photosystem II assembly, thylakoid membrane organization, chlorophyll biosynthesis, and photosynthesis . These data suggest that alteration of photosynthesis is an important strategy in response to desiccation for M. flabellifolia. Moreover, genes involved in isopentenyl diphosphate biosynthesis were enriched in moderately dehydrated, desiccated, and rehydrated leaves . Isopentenyl disphosphate is a precursor of all plant isoprenoids,which are a diverse group of metabolites including primary metabolites such as sterols, chlorophylls, carotenoids, quinones, and hormones and secondary metabolites participating in plant defense and communication such as pigments, volatiles, and defense compounds.To further delineate the metabolic pathways participating in the dehydration and rehydration responses, we mapped the DTGs into the Kyoto Encyclopedia of Genes and Genomes database. A total of 23 and 18 biochemical pathways were significantly enriched during dehydration and rehydration, respectively . During dehydration, consistent with the GO enrichmentanalysis, the enriched biochemical pathways involved diverse metabolites, including secondary metabolites, starch, sucrose, fatty acids, fructose and mannose, and photosynthesis, suggesting a global response to desiccation in M. flabellifolia. As one example, the flavonoid biosynthesis pathway was significantly enriched during dehydration, consistent with the role of anthocyanins, a flavonoid class, in the ‘green-to-brown’/‘brown-to-green’ leaf color alternation during dehydration and rehydration.During rehydration, photosynthetic genes were significantly enriched . This is consistent with a previous study in M. flabellifolia showing that photosynthesis resumes rapidly, reaching full capacity within three days of rehydration.The recovery of vital functions and metabolic activities during rehydration is indicated by alterations of genes encoding a range of structural and physiological processes.For example, genes encoding enzymes involved in ribosome and aminoacyl-rRNA biosynthesis, essential for the re-establishment of normal cellular metabolism, are enriched during rehydration .

A 0.5 μl sample was injected into the liner in splitless mode, and the liner was exchanged every ten samples. The injection temperature started at 50o C and ramped to 250o C by 12o C per sec. The GC column was a Rtx-5Sil MS at a constant flow of 1 ml min−1 helium gas. The column temperature started at 50o C for 1 min and then ramped to 330o C. Automatic mass spectral deconvolution was performed with peak detection of GC spectrum using The BinBase algorithm . After peak peaking, peak data were deposited BinBase DB with BinBase ID. BinBase settings: validity of chromatogram , unbiased retention index marker detection , retention index calculation by 5th order polynomial regression. Spectra are cut to 5% base peak abundance and matched to database entries from most to least abundant spectra using the following matching filters: equivalent to about ± 2 s retention time, unique ion must be included in apexing masses and present at > 3% of base peak abundance, mass spectrum similarity must fit criteria dependent on peak purity and signal/noise ratios . Failed spectra are automatically entered as new database entries if s/n > 25, purity < 1.0 and presence in the biological study design class was > 80%. Resulting .txt files were exported to a data server with absolute spectral intensities and further processed by a filtering algorithm implemented in the metabolomics BinBase DB .At the molecular level for resistance in initial infection stages,vertical farming equipments a lack of bacterial propagation, induction of vir, and incomplete integration of T-DNA result in crown gall resistance in grapevines . V. riparia that showed RR in our study had a broad range of crown gall resistance by particularly inhibiting the integration of A. vitis T-DNA into plant chromosome .

This type of resistance prevents the pathogen from infection, resulting in the reduced GI, leading to no or little gall development to have also lowered GDI, which may be applied as a major resistance mechanism for the four Vitis species of RR. For SR, GI was similar to SS, but GDI, to RR, suggesting the pathogen infection in SR occurs as in SS, but gall development is retarded as in RR to have moderate GSI between SS and RR. For SS, both A. vitis T-DNA integration into host genome and expression of encoded plant oncogenes and increase in phytohormone levels occur readily, resulting in the formation of tumors and their proliferation . Out of a total 134 metabolites produced in the grapevine stem internodes infected with A. vitis K306, 11 metabolites were significantly related with response types of 10 Vitis species examined in our study. At pre-inoculation stage, only one metabolite was significantly increased in RR relative to SR, while all 11 metabolites were significantly increased in either SS or RR at post inoculation stages, suggesting metabolic changes may occur preferentially around the infection sites after the pathogen infection, especially at initial stages of the pathogen infection with response type-related 8 metabolites, of which 6 related to SS but only 2 most significantly related to RR and SR . At post 2 , all three metabolites were more related to SS than RR or SR; however, at post 3 all three metabolites were more related to RR or SR than SR and/or SS. These all suggest that the metabolic changes occur actively in relation to susceptible responses at the initial stages after the pathogen infection, but in relation to resistant responses at later infection stages with full gall development.

An amine derivative, octopine, produced by the octopine-type A. vitis used in our study and two plant hormones, auxin and cytokinin, produced in the T-DNA transformed plant cells, drive the uncontrolled gall development, determining gall morphology depending on the ratios of the plant hormones . However, neither octopine and its amino acid component arginine nor the plant hormones were produced in a significant level around the infection sites in our study, suggesting the gall-inducing metabolites may hardly be transported out of the tumorigenic tissues. However, the component class most abundantly produced in relation to response types was amino acid in our study, including 4 amino acids produced at post 1 and one at post 3, which was significantly related to SS and RR, respectively. The functions of these amino acids in crown gall development have not been clearly understood, but amino acids are generally involved in the primary metabolism of all living organisms, and the developing tumor becomes a metabolic sink accumulating metabolites to be supplied in a priority for its growth by the induction of vascular tissue differentiation around gall surface . It was reported previously that three SS-related amino acids except tyrosine increase several folds in tumor tissue at later infection stage , suggesting also these SS-related amino acids should be related to the gall development, although the time for the production of the materials may differ depending on Agrobacterium species. Other component classes of the metabolites such as carbohydrates and carboxylic acids which were increased in SS at 2 and 7 days after inoculation, respectively, may also serve for the gall growth and differentiation by inducing vir genes; gallocatechin, a flavonoid, may be involved in the gall formation as a potential auxin transport regulator as in root nodulation and root-knot gall formation . Quinic acid, catechins, and stilbene are related to Pierce’s disease, showing these metabolites occur at great levels in xylem tissues of the grapevine infected with Xylella fastidiosa.

In plants, major resistance-related responses to Agrobacterium spp. occur at two periods of time, initially at the time of recognizing the tumorigenic pathogens and later during the time of the pathogenesis in which auxin and cytokinin cause an increase of ethylene that together with salicylic acid inhibits agrobacterial virulence . In our study, resveratrol at post 1 and valine and xylonic acid at post 3 were definitely differentiated as RR from the other response types . Resveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced naturally by several plants in response to injury or pathogen infection . In grapevine, resveratrol is primarily found in the grape skin and produced as phytoalexin in grapes infected with the grey mold pathogen, Botrytis cinerea, of which the accumulation amounts vary with grapevine genotypes, their geographic origin, and exposure to fungal infection . Considering the biological characteristics of this stilbene compound , this metabolite may be produced in Vitis species with RR at a significant amount and act as a phytoalexin to inhibit the growth and virulence of the tumorigenic pathogen probably more at initial infection stages. For the other metabolites increased in Vitis spp. with RR at the later infection stages , valine , and xylonic acid ,vertical farms their roles in plant responses are not clearly understood. Alterations in the plant metabolism in response to different pathogen infections may function as either supporting the ongoing defense mechanism to lead an efficient resistance response or being exploited by the pathogen to facilitate infection as can be seen in plant glutamate metabolism . Thus, it is not an unusual thing that the metabolites in the same compound classes were differentiated in relation to the opposing response types; xylonic acid significantly related to RR at post 3, while quinic acid to SS at post 2; valine related to RR at post 3, while four amino acids to SS at post 1 in our study. Considering the same class metabolites concomitantly occurred in relation to different response types at different infection stages, the same class metabolites may play different roles depending on their requirements for in situ metabolism, leading to either compatible or incompatible responses to the pathogen infection In our study, sucrose contents were highest in grapevine stem internodes with SR at post 1 and post 3, which was significantly differentiated from SS at post 1 and RR at post 3, respectively . Considering the increased expression of sucrose degradation enzyme genes in gall tissues of Arabidopsis and its induction of Agrobacterium virulence genes , the increased sucrose contents may support its intake into the metabolic sink, crown gall tissue, contributing to the gall development in different degrees depending on infection stages . Host sucrose, synthesized from photosynthetic products in the cytoplasm of aerial plant parts, is transported to tumor cells apoplastically and the sucrose contents in phloem sap differ depending on the crown gall-developmental stages with higher around actively growing young galls than old matured ones .

In our study, the sucrose contents fluctuated with time after infection and were higher at post 1 than post 3, regardless of response types, suggesting the uptake of sucrose should be required for the gall development. Another carbohydrate cellobiose was significantly higher in RR relative to SR at preinfectional stages, but higher in SS than RR and SR at post 1, suggesting its roles in healthy plant tissues may alter oppositely in diseased plant tissues with uncontrolled gall development. In our study, metabolite profile analysis revealed the following aspects: Remarkable differential increases of metabolites occurred in internodes of Vitis species after A. vitis infection, most prevalently at two days after inoculation, and more related to susceptible type of response for 10 metabolites that are useful for the metabolic processes in gall growth and differentiation as nutritional compounds or plant hormone regulator. Among three metabolites definitely differentiated into the resistant response , resveratrol appeared to be importantly related to resistant responses as it is a well-known phytoalexin compound in several plant pathosystems. All of these aspects will provide important information that can be applied for the selection of grapevine cultivars resistant to the crown gall disease caused by A. vitis, and their use as root stocks for the control of the crown gall disease in the scions of the grapevines susceptible to A. vitis. Abscission is the process of organ separation, which plays a critical role in the plant life cycle. Organ shedding occurs at abscission zones , comprising small, densely cytoplasmic cells at the boundary between an organ and the main plant body. Abscission has evolved as a successful strategy to adapt to the environment in response to developmental and environmental cues. Abscission allows plants to detach nonfunctional or diseased organs and is also important for seed dispersal. The timing of abscission, especially of flower and fruit abscission, is of interest to agriculture. Breeding of appropriate abscission behavior has successfully solved crop production and yield problems such as grain shattering, cotton boll shedding, premature legume dehiscence, and mechanical harvest in tomato. It has been well-demonstrated that the timing of abscission is regulated by cross-talk between the phytohormones auxin and ethylene.Arabidopsis flower abscission is inhibited, for example in the ethylene-insensitive mutants ethylene resistant 1-1 and ethylene insensitive 2. In tomato too, organ abscission is inhibited in ethylene receptor and ethylene sensitivity mutants including EIN , Never ripe , Sletr1-1, and Sletr1-2. Auxin plays a critical role in controlling abscission. The consensus of many studies is that the continuous polar flow of auxin passing through the abscission zone inhibits abscission and that reduction of this flow initiates abscission by making the AZ sensitive to ethylene. The polar flow is thought to be a reflection of agradient in auxin concentration across the abscission zone. In a series of classic experiments, it was shown that application of indole-3-acetic acid , to the distal side of Phaseolus vulgaris leaf explants inhibited abscission, while an application to the proximal side accelerated the process. The nature of the auxin gradient continues to be the subject of discussion—researchers have proposed that the gradient might be in auxin concentration, auxin biosynthesis, auxin transport, and/or auxin response. In Arabidopsis, manipulation of auxin biosynthesis specifically within floral organ AZ demonstrates that reduction of auxin level makes the flower organ shed prematurely. However, the disruption of auxin signaling/ response in AZ delayed the shedding of floral organs, suggesting that a functional IAA signaling/response pathway in AZ cells is required for abscission initiation. Given the importance of auxin balance between the distal and proximal sides of the AZ for organ shedding, it is essential to understand how this auxin gradient is maintained for regulating the initiation of the abscission process in response to developmental and environmental cues.

The energy savings produced could be used to assign an economic value to the micro-climate regulating services provided by the green space. Animal-mediated pollination is an important ecological process that supports many benefits . For example, bee pollination can increase agricultural crop quantity, food quality, and market value . However, bee populations have been declining due to pollution, higher pathogen prevalence, and lower genetic diversity . Additionally, development and urbanization cause habitat fragmentation which can lead to changes in species and functional diversity .Pollinators, such as bees and birds, can connect these habitat patches as they move along plants to feed and collect pollen . Increased suitable habitat and connectivity may facilitate the recovery of pollinator populations and create more resilient communities that can recover from disturbances, e.g. disease or long periods of intense drought . Habitat patches have been shown to maintain distinct bee communities that, in aggregate, retain a significant amount of local species diversity . The value of pollination services is typically associated with increases in agricultural productivity ,vertical grow rack but has also been evaluated in urban settings. Breeze et al. estimated WTP for non-market pollination services in the United Kingdom using a discrete choice experiment. Their estimates suggest taxpayers are willing to pay 13.4£ annually per person to maintain these benefits.

Visual indicators for potential pollination services include the presence of animal-pollinators as well as flowering plants. Quantification of this service requires data on the frequency of animal-to-flower visits as well as connectivity among NTS and other areas.NTS can have built-in, public spaces that human communities can utilize. Walking trails, bike lanes, benches, and wildlife viewing sites can provide recreational services . Urban green spaces have been linked to improvements in physical and mental health . They have also been linked to more active and healthy lifestyles overall . In Los Angeles County, which has the third highest population density in California , these types of spaces can be important in the midst of a denselypopulated and highly-urban area. The travel cost method is most often used to calculate the value of recreational services, but it may not be appropriate for hyper-local neighborhood amenities because of little-to-no cost associated with access . Contingent valuation and hedonic pricing have also been employed . The latter alludes to an equity question regarding who is paying for these spaces and who is benefitting from them. In Porto, Portugal, Graça et al. found that lower socioeconomic areas have the most green space but they are unlikely to be developed in ways that provide services to the community. This suggests that recreational services provided by green spaces can be a luxury.NTS present an opportunity for education and public outreach regarding storm water issues, pollution, watershed and urban ecology, urban planning and management, and climate change. For example, Ocean View Growing Grounds is a community garden within a food desert in inland San Diego.

OVGG incorporates bioswales into its landscape, meant to prevent crops from flooding. UC San Diego researchers have partnered with community leaders to host outreach events about hydrology, soil, and urban ecology. Greater understanding and awareness of NTS and the services they provide may lead to safer gardening practices and more efficient water use. In Los Angeles, many of the sites have educational information posted about the project, their goals, and their motivations . As part of the Elmer Avenue Green Street project, local residents participated in the planning and design processes, actively engaging in storm water issues and how to address them. Scientific research on storm water issues have proven useful, especially in developing countries where water quality is often a main concern but resources and infrastructure for large treatment plants are lacking .NTS can introduce undesired services, such as installation of unattractive elements, accumulation of pollutants, and proliferation of disease vectors. The aesthetics of NTS may not be favorable to all people, especially when they are not regularly maintained. Southern California receives very little precipitation which can be fatal for plants that are not drought resistant. Additionally, plant communities in NTS by the ocean have an added stressor of salt . This may highlight the need for use of native vegetation in NTS in order to facilitate their survival. Whether or not they are also the most aesthetically-pleasing is subjective. Regular maintenance can, not only help plant survival, but also prevent build-up of debris and pollutants, which NTS are designed to intercept. Debris degrades aesthetic value but other pollutants can cause environmental damage. Heavy metals can leach into surrounding soil and groundwater . Ponding areas, that allow microbial communities to remove contaminants, can also provide habitat for mosquitoes which pose health hazards in the form of infectious diseases and allergies.

For example, two Los Angeles NTS sites had advisories about West Nile virus and its carriers. Vegetation and soil media can also provide habitat for urban pests, such as rodents and ticks . Increases in urban green space have been linked to decreases in violent crime , but may also provide spaces in which crime can happen, e.g. assault or vandalism. Several accounts of assault were cited in the South Los Angeles Wetland Park . Almost all of these issues can be avoided at some cost whether it is increased maintenance, more frequent monitoring, or a greater police presence. The main warning here is not that these costs are usually prohibitively expensive, but that they need to be considered when planning. In summary, NTS that rely on natural structures and functions, e.g. bio-retention systems and treatment wetlands, provide built ecosystems that can support a host of targeted and non-targeted benefits . While there are few data on the quantification of these benefits in NTS specifically, we can draw on examples from relevant systems to get an idea of how these processes may work and on what scale. There also exist many economic valuation techniques that can be employed to assign a value to these ecosystem services for incorporation into urban design and management. Cost is a component of NTS in which urban planners are likely interested. Total costs consist of planning and design, permitting, raw materials, installation, maintenance, and monitoring. Most NTS are implemented in order to meet water quality regulations and, although expensive, they may be cheaper than alternative approaches. Additionally, continued use of NTS may be a sign that their co-benefits can be significant. Long term monitoring is necessary in order to assess whether the benefits discussed in here truly exist.There are two distinct objectives that need to be addressed in order to assess ecosystem services associated with NTS: the first is to determine the quantity or rate at which the ecosystem service is provided ,vertical planting tower and the second is to determine the economic value of that quantity or rate. Targeted water services have been well-documented in laboratory settings but in situ, mesocosm studies are much fewer. Similarly, although non-targeted ecosystem services are acknowledged , quantitative field studies are only just beginning to emerge. Researchers from the University of California are currently working on an interdisciplinary project that assesses the form and function of urban storm water infrastructure in southern California, including potential ecosystem services . In the following section, we discuss three potential models for ecosystem services assessment in NTS: benefit transfer approaches, stochastic frontier analysis, and data envelopment analysis. Benefit transfer approaches can be used to assign physical and economic values to ecosystem services for cost-benefit analysis. The latter two approaches, represented by production frontier models, can assess how efficiently an NTS is providing ecosystem services which may be a useful assessment tool for environmental decision-makers. Although there are few data currently, these models can be used as a starting point and improved upon as more data become available.Meta-analyses provide a database on which a regression model can be built, determining the relationship between a dependent variable and multiple explanatory variables. Meta-analyses are a method of synthesizing results from multiple studies on similar topics . They are often utilized when many studies exist and interpretation of their results is difficult, and so synthesis of results can be a helpful tool . Meta-analyses can also be useful in contrasting situations in which very few studies exist for the target system but fall within the range of systems that have been studied. For example, a keyword search of “urban carbon” in the Environmental Valuation Reference Inventory yields 76 records but only 6 studies are specific to urban green space . Regression models can then be built upon the information collected during meta analyses. In the example case of ecosystem services associated with NTS, three categories of independent variables may be relevant: the biophysical and the socio-economic characteristics of the study site, and the study characteristics.

Examples of potential explanatory variables include study site size, geographic location, scale of the study , gross domestic product per capita, valuation method, and sample size. Benefit transfer approaches use regression models to provide an estimate of the dependent variable . In addition to benefit transfer based on a function estimated from a meta-analysis, a unit value or a function estimated from one study can also be used. However, the meta-analysis approach described here is preferable because it can account for differences between the policy and study sites. The “policy site” is the site of interest and “study sites” are those from which values have been transferred. The best benefit transfer estimate will be that between policy and study sites that are identical in terms of biophysical and socio-economic characteristics. However, there are generally discrepancies among commodities, currencies, user attributes, wealth measures, and cultural differences between policy and study sites that can lead to errors . Although primary studies are ideal, they are not always feasible, given the high cost of resources and time. It is useful for government agencies to sponsor studies across NTS that provide different quantities of ecosystem services and try to value that output in a way that is likely to be more accurate for a local context.Cost-benefit analysis, a widely-used tool for decision-making, compares the economic costs and benefits of one or more decisions . If the costs outweigh the benefits, then rational actors do not partake in the action, and vice-versa. However, there are additional factors that make decisions more complicated, such as the long- versus short-term, discounting, and positive and negative externalities. Cost-benefit analysis is often used in environmental decision-making but ecosystem services are often only included qualitatively because quantitative data do not exist . The use of benefit transfer approaches can help this process by taking a first-step towards economic valuation of ecosystem services.The SFA approach is a parametric economic modelling technique that allows for random shocks, or unpredicted events, within the model. The stochastic error term may make it suitable for urban systems that are subject to environmental variation, e.g. drought, precipitation events. SFA requires a priori assumptions regarding the production function form, i.e. the mathematical relationship between inputs and outputs , and the distribution of the unobserved technical inefficiency terms, which can substantially influence results. A considerable econometric literature has been developed to help determine the adequacy of the statistical fit of a particular model. The SFA approach provides a natural measure of how inefficient a particular NTS is at providing an ecosystem service relative to other NTS configurations. DEA is a nonparametric approach that does not allow for random shocks but it does not require prior knowledge of the production function form, which makes it useful for NTS-associated ecosystem services. DEA combines inputs and outputs into one efficiency score that can be easily compared, but it requires an additional regression model to identify the impacts of independent variables. Both DEA and SFA are capable of handling multiple outputs but in SFA, they must be collapsed into one basket of outputs whose weights can have a significant impact on results. One way to weight outputs is by their economic values. However, economic values for most ecosystem services associated with NTS have not been assigned, i.e. why benefit transfer approaches may be helpful. The lack of standardized monitoring data may make a nonparametric DEA approach more feasible at this time, in addition to the SFA requirement to specify a production function form. DEA also better handles multiple outputs relative to SFA and undesirable outputs, such as negative externalities .

Paprika and coffee are also less labour intensive than tobacco and so may be easier to manage for households with a shortage of active workers. On the other hand, these enterprises still require more labour than other traditional smallholder crops including cotton and the need for most households to hire workers if cultivating a large area may discourage some producers. Table 27 compares estimated net profits for non-traditional smallholder crops. As with the results for LSC farmers, these data clearly show that other crops offer a potential for comparable and sometimes higher profits than tobacco. Since these crops also cost less to produce than tobacco, paprika and coffee appear to be excellent alternatives for smallholder growers. As noted, successful development of these crops depends on many things including major investment in support services and infrastructure.Coffee was first introduced in the 1960s on LSC farms in Natural Region I near Chipinge in the Eastern Highlands. Until the mid-1990s, very little coffee was grown outside this area and the Eastern Highlands still account for more 70% of all exports. This situation is now set for great change in that LSC farmers in tobacco growing areas of Natural Region II have been planting large areas to coffee in an effort to diversify their income base. Of the total 9 900 hectares now under coffee in Zimbabwe,vertical growing systems some 5 500 hectares are immature 1-2 year old trees grown on tobacco farms.

When these plantations come into full production over the next 3 years, total annual exports are expected to increase from around 7 000 metric tons of green coffee at present to over 20 000 metric tons. Current export values are in the range of USD 8.1 million; once the trees already planted are fully mature, this could easily increase to over USD 43.5 million, equal to about 7.5% of the gross foreign income from tobacco.15 Zimbabwe grows high quality Arabica coffee that normally attracts a 10% to 20% premium in the world market.Coffee is now one of the fastest growing agricultural sectors in Zimbabwe and is being financed mainly by individual LSC farmers with income from tobacco. As a tree-crop, coffee takes around three years to mature until the first major harvest and few banks are willing to lend for this type of long-term project, especially in the current economic climate.In addition to the trees themselves, other establishment costs include pulping machines, fermentation tanks, drying racks and, ideally, drip line irrigation. These costs can easily add to more than ZWD 10.6 million for a 60 hectare project until the trees are fully mature.Government does not control the coffee industry and individual LSC farmers are free to market their crop directly in US dollars. Coffee prices are based on the New York Futures Market and most growers are able to fix prices up to 12 months in advance. An important advantage of this system is that sales against a forward contract can be used to obtain credit and help smooth individual cash flow requirements. Currently, however, New York coffee markets are suffering from a large oversupply and are at their lowest point for 25 years equal to an average fob export price of only USD 1 360 per metric ton from the Mutare Coffee Mill. Analysts predict the situation will improve over the next 12 months and export prices around USD 2 000 per ton fob Mutare are more indicative of the long-run average.

Therefore the quantitative analysis is carried out using three price scenarios: the current low price , a long-run average price and a middle price.Large-scale commercial farmers. Quantitative results from the analysis of LSC coffee grown in Natural Region II are summarised in Table 28 for a mature, four year old crop.Because coffee is grown to a more or less uniform standard, only two management levels are considered for this enterprise. In this case, the medium input level is based on a conservative yield of 2.0 metric tons per hectare used for most farm budgeting exercises in Zimbabwe. Compared with large commercial farmers in southern Zambia, however, where growing conditions are more or less similar, this is a fairly low yield and it is not unrealistic to expect at least 2.5 tons per hectare for a mature crop with good management. The high input level is based on this expectation.Key results from the quantitative analysis have already been compared with the data for flue-cured tobacco in the overview section above. Without repeating this discussion, it is useful to note that farmer profits improve by proportionately more with higher crop prices than the price increase itself. Furthermore, even though crop profits are very low with current prices , coffee still returns a gross profit and therefore contributes to the viability of a mixed LSC farm system. In other words, even under very difficult market conditions, coffee is still an attractive enterprise with great potential for increased profits as prices improve. In terms of the two management levels, the data suggest there is further potential for even higher profits through better management and increased yields. It may not always be possible to achieve 2.5 tons per hectare because of local agro-climatic conditions, but the potential for significantly greater profits no doubt means that some farmers already target this level.Smallholder farmers.

There are around 2 000 registered smallholder coffee growers in Zimbabwe located exclusively in the Eastern Highlands. Most growers are organised into co-operatives that manage the pulping and milling of smallholder coffee and oversee international marketing, which is handled on commission by the Mutare Coffee Mill. Smallholder farmers currently produce about 30 metric tons of green bean coffee annually equal to about 1.5% of the national total from an area of just over 100 hectares. Although smallholder coffee has not been promoted in the northern flue-cured areas, the quantitative analysis helps to assess the overall viability of this enterprise. As described, the major challenge with promoting smallholder coffee in these locations would be that pulping and processing facilities have to be developed. Simple irrigation facilities, including water furrows and treadle pumps, may also be needed for high yields depending on local conditions. Smallholder coffee, therefore,outdoor vertical plant stands is more likely to substitute for burley tobacco grown in eastern Zimbabwe where there is better access to existing pulping and processing equipment.The quantitative results for smallholder coffee are summarised in Table 29 below. These models assume farmers have access to pulping and processing facilities and no account has been taken of the cost for Zimbabwe to develop these services. Although more through analysis is needed to assess the viability of introducing coffee to a new location, the results here suggest this may be a very attractive proposition. Most encouragingly, the results are especially favourable with low input management where coffee costs less than almost every other enterprise analysed and provides relatively high profits similar to cotton.On this basis, the rates of return are outstanding and indicate that coffee can be a very good low risk investment for smallholder farmers. With more intensive management and/or improved world prices, the returns from coffee rival tobacco. Although somewhat labour intensive because of the time spent picking, crop profits improve significantly with more intensive management and the returns to family labour at these higher levels are similar to the very good daily returns from tobacco. Paprika was first introduced to Zimbabwe in the early 1990s by private investors who sought to promote the crop mainly among large-scale commercial farmers. One advantage of paprika is that the soil types and skills required are very similar to those needed for tobacco so that farmers are already well positioned for success. Compared with tobacco, however, world markets for paprika are relatively small with a total demand of only about 120 000 metric tons per year. Production in Zimbabwe has ranged from 8 500 to 15 000 metric tons annually and, in the years when production peaked, this had a noticeable impact on world prices which discouraged many LSC farmers from continuing to grow the crop. Until recently, paprika buyers typically offered LSC farmers production contracts with a guaranteed minimum price fixed in USD at the start of the season. Deteriorating economic conditions, however, mean this is no longer feasible for most export companies.About 70% of world paprika is used as a condiment in powder form with the balance sent for hexane extraction to derive a colour lipid for industrial food processing. Until now all paprika grown in Zimbabwe has been dried, de-seeded and exported in baled form for processing outside the country. This situation is about to change, however, in that one local firm has nearly completed a new solvent extraction plant with the capacity to process 1 000 to 1 500 metric tons of paprika annually. Once operational, this facility will help add value locally and save on high overland transportation costs for bulk paprika.

Although there has been much private investment in Zimbabwe to promote paprika among LSC farmers , relatively little attention has been given to smallholder growers for the past 2-3 years. Neighbouring countries including Zambia and Malawi have enjoyed some measure of success with smallholder paprika, but buyers in Zimbabwe prefer to work with LSC farmers who are a more reliable source of supply and able to produce higher quality crop that is easier to market internationally. Buyers in Zimbabwe also consider that paprika is a risky enterprise for smallholder farmers because of problems with crop disease and potential for yield loss from localised flooding and other conditions these growers cannot control.Large-scale commercial farmers. The results for LSC paprika are summarised in Table 30. For this analysis, two management levels are considered including a late-season, low-cost crop planted with the rains and a long-season crop aiming for very high yields.As discussed in the overview section above, these results compare very favourably with those for flue-cured tobacco. Although limited world demand means that paprika could never substitute entirely for tobacco, the crop clearly has the potential to provide high farmer profits and so can play important role in a mixed farm system. In terms of employment creation, paprika demands an estimated 70 to 80 days of casual labour per hectare and is among the most labour intensive crops analysed. The rates of return and sensitivity indicators for both short- and long-season paprika are excellent and show this is a robust activity that remains profitable even with a significant reduction in price. Smallholder farmers. Despite limited interest by most private buyers in paprika as a smallholder crop, some promotion and training work was carried out a few years ago in tobacco areas and there are now several thousand smallholder farmers who cultivate the crop each year. Around 75% of smallholder paprika is grown in Natural Region II on very small plots of just 0.1 to 0.2 hectares on most farms. In 1999, a total of 12 500 smallholder households planted paprika over an area of 1 600 hectares for all natural regions; there were 9 800 growers in Natural Region II cultivating a total of around 1 200 hectares. Paprika is priced according to colour and smallholders generally produce a lower-value crop than LSC farmers. Contamination with foreign matters including dirt, stones and even rat hairs because of poor on-farm storage also lead to lower crop value and restricted export opportunities.Results from the quantitative analysis of smallholder paprika are summarised in Table 31. Although production and marketing risks cannot be overlooked, the data for smallholder paprika compare very well with those for smallholder tobacco. Not only are the estimated profits comparable to those from burley and even flue-cured tobacco, but paprika also costs less to grow at each corresponding management level. These are attractive characteristics for smallholder farmers for whom the ability to afford purchased inputs can be a major constraint. Compared with tobacco and all other crops analysed, the data show that paprika offers outstanding rates of return to both cash and total production costs. Furthermore, despite the perception among many buyers that paprika is a risky crop ill-suited to smallholder production, the sensitivity data show that the very good financial results for this crop are extremely robust and suggest that smallholder farmers may be well positioned to compete in the world market even with lower prices.

In the pavement industry, the majority of the materials used for construction, which are primarily composed of gravel, sand and crushed stone, are relatively local materials, unless there is access to water transport. An exception is specialized engineered materials/chemicals such as admixtures and additives. Figure 8 shows the order in which user input/selection is required before the tool outputs a comprehensive summary data of different commodities in tons, ton mile and/or dollar costs in tabular form. In this white paper, examples of domestic flow types are presented. Within the domestic flows, seven tables are presented that require user input. Each table has a drop-down list to select from. The CFS data is being collected every five-years since 1997. Data were also collected for the years 2013, 2014 and 2015. Additionally, users can extract future projection data based on macroeconomic forecasting model starting from 2020 to 2045 for every five-year interval . The origin and destination can be at the country, state or city level. The city and state boundaries in FAF4 are defined as FAF zone specific and the 132 domestic zones are a hybrid of core-based statistical areas that have been defined by the office of management and budget and state boundaries . As noted in the introduction, modeling of climate change indicates that the intensity of rainfall during extreme events will increase significantly, with the amounts depending on the extent of continued human contributions to greenhouse gases . Increased urbanization is one of the factors that has affected urban flooding and storm water runoff due to development in the flood plains and construction of impervious hardscapes. Figure 9 through Figure 11 show qualitatively how degrees of average perviousness of urban surfaces affect storm water runoff,vertical grow shelf infiltration and evapotranspiration.

The Environmental Protection Agency Storm Water Management Model is a simulation program which can perform dynamic rainfall-runoff modeling . The simulation can be conducted for both a single event or over a longer period of time and the program can analyze quantity and quality of runoff from different urban regions. The SWMM model works based on an assembly of sub catchment regions in which precipitation is received and runoff is generated. SWMM then uses simulation of a combination of pipes, storage devices, pumps and regulators, to model transport of this runoff. SWMM can record the quality and quantity of generated runoff in each of these sub catchments. It also can calculate the flow rate, flow depth and quality of water in pipes and channel sections for the duration of simulation. The hydrological processes that can be simulated in SWMM include evaporation, snow accumulation, infiltration, percolation of infiltrated water, water inter flow between groundwater and drainage system, etc. To overcome spatial variability in all these processes, the actual area of interest is divided into smaller sub catchment regions in which the hydrological properties are homogenous. Then, the overland flow can be dispelled between sub catchments, drainage systems or sub-areas. SWMM is also capable of analyzing runoff pollutant loads under different conditions such as dry-weather pollutant buildup, pollutant wash-off during storm incident, contribution of rainfall deposition, and reduction of concentration due to water treatment. The UM-LCA framework developed for this study aims to build a foundation for future assessments of alternative types of urban hardscape. Using materials such as pervious concrete, permeable pavers and porous asphalt and designs for construction of permeable pavements that allow the storm water to pass through the structure into the ground water table is one way to reduce storm water runoff through infiltration and detention, which also increases groundwater recharge and can help improve storm water quality. The water cycle can be quantified using the SWMM model.

SWMM provides additional capabilities relevant to urban hardscapes. There is an additional section called Low Impact Development which defines the properties of low impact technologies such as the permeable pavements. LID is an approach that manages storm water on-site by sustainable land planning and engineering design practices i.e., use of recyclable materials, permeable hardscape designs, and in-place recycling are some of the example practices. The LID module in SWMM includes the following technologies: bio-retention cell, porous pavement, infiltration trench, rain barrel, and vegetative swale. The Atmosphere Compartment contains climate information which determines how much precipitation LID will receive. The Land surface Compartment contains information about LID’s area.The Ground Water Compartment depends whether the LID allows storm water to recharge ground water. For example, the green roof conveys storm water into the drainage pipes and the water does not infiltrate into the ground directly. Therefore, in this case the Ground Water Compartment can be omitted. However, use of Ground Water Compartment is necessary if a structure, such as permeable pavements, allows water to infiltrate into the groundwater table. The climate information and rainfall are required for almost all the SWMM simulations. The data can be collected from National Climatic Data Center . The information about the modelled area is also one of the required inputs. As mentioned earlier, SWMM divides the defined area into several sub catchments according to the land usage . The properties of the subcatchment are: ’X-Coordinate’ and ’Y-Coordinate’ which defines the location of the sub catchment area on the map, ‘Area’ which shows the size of the sub catchment, and ’Rain Gauge’ which determines the duration and intensity of the rain.

The following are input parameters that are used in the LID module: surface layer, pavement layer, storage layer, under drain layer, and subgrade layer. After completion of the analysis, LID provides the following outputs: total inflow volume, total evaporation loss, total infiltration loss, total surface outflow, total under drain outflow, initial storage volume, and final storage volume. These outputs are available for any analyzed time step and can be viewed on the map in the program, tabulated or plotted for the further statistical analysis. Several data sources have been determined that can be used in the SWMM model as inputs. Data from cities in California was taken as an example to illustrate what type of information can be extracted from the sources reported in order to run the SWMM model. The following sources can be used to collect the information of the rainfall and climate for cities and regions in the U.S.Zimbabwe’s economy depends heavily on tobacco. There is concern that global efforts to reduce tobacco use may reduce demand for tobacco and significantly affect Zimbabwe’s economy and tobacco exports. Global tobacco demand has recently been stable or falling very gradually. However,vertical hydroponic public health efforts to reduce demand are offset by aggressive cigarette marketing, rising population and incomes, and the strongly addictive effects of nicotine. But tobacco prices have softened, and the long-term prospects are uncertain. Governments concerned about the future of tobacco are considering diversification options and strategies to develop other high-value crop substitutes . The world’s fourth largest flue-cured tobacco producer and the largest producer of tobacco leaf in Africa, Zimbabwe exports 90 percent of its raw tobacco and has typically earned around USD 600 million in foreign revenue annually, equal to almost 10 percent of GDP, 30 percent of total exports and 50 percent of agricultural exports. Moreover, 250,000 people or 5% of Zimbabwe’s total labor force are engaged in tobacco-related work including tobacco farming, manufacturing and retailing. Most tobacco in Zimbabwe is grown by large-scale commercial farmers, who account for about 87% of the land under tobacco and 95% of the total crop. This study compares the financial costs and returns to tobacco with twelve alternative crops, looking at profitability, costs, labor intensity, financial support, technical infrastructure, land-suitability, marketing difficulties, world demand, and production risks. The information may be useful to agriculturalists and government officials who are interested in exploring the potential for diversification by different sized farmers, as Zimbabwe considers options for the future. The study aims to provide an improved understanding of the trade-offs individual growers face in deciding what crops to grow. The analysis is based on an original set of 91 production budgets estimated in January 2001 specifically for this study, that estimated financial costs and returns in Natural Region II at the time. It should be noted that in 2000/2001, veterans of the independence war occupied several commercial farms and Government subsequently gazetted over 5,300 farms for compulsory acquisition and resettlement. This study took place before the impact of these events on agricultural output was evident, and does not address whether and how they might affect tobacco farming and its contribution to the economy of Zimbabwe. The study shows that tobacco is a highly profitable cash crop for both large and small farmers, generating direct income for large-scale farmers, and indirect income for smallholder farmers.

Dramatic changes in prices and yield are unlikely in the near future. And tobacco would remain relatively profitable, even if prices fell considerably. Farmers in Zimbabwe are aware of the risk of depending on one cash crop and have begun diversifying to lessen their tobacco dependence. Large scale commercial farmers have diversified into coffee and paprika, and horticultural crops – notably roses and supermarket vegetables- using their tobacco profits. These products can be grown in the same soil as tobacco, and generate high profits as well as employment opportunities. The study discusses the limitations of these alternatives, and notes that despite some rapid increases in some crops , they are still grown at a very limited scale compared with tobacco. Tobacco is one of the most profitable cash crops for both large-scale commercial and smallholder farmers. The study shows that tobacco would provide good financial returns even after a large drop in yield or price. Tobacco is likely to remain a very attractive crop for all categories of farmer even under progressively difficult market conditions. There are around 2,000 large-scale commercial tobacco growers, and 16,000 tobacco growing smallholder farmers – less than 1.5% of all smallholder households. Most smallholders grow only very small amounts of tobacco, in part because few smallholders have land that is suitable for intensive farming of tobacco. Even for farmers in suitable agro-ecological areas, however, tobacco is expensive to grow, with high up-front costs that smallholder farmers may not be able to cover. For example, high costs of production of flue-cured tobacco are a barrier to most cash-poor smallholders in tobacco areas. The financial incentives to smallholder farmers with the appropriate land to grow tobacco are, however, strong with the relative returns to cash and labor considerably higher than for most other crops. Most commercial farmers already have diversified sources of income, and have introduced various high-value crops including export roses, supermarket vegetables, paprika and coffee as part of their farm system, specifically to lessen their dependence on tobacco. As with all business decisions, the challenge for farmers is to find the right blend of crop enterprises that works best for them. Beyond the enterprises covered here, for example, the study indicates that, other than the crops discussed in the study, many other niche products also offer diversification potential for smallholder and LSC farmers including mushrooms, flower seeds, medical plants and spices. Citrus crops, including oranges, grapefruit and lemons are an important diversification option with more than 88,000 hectares of orchards planted on LSC farms as of 1999. Game ranching on LSC farms has been another popular diversification activity and can provide an important source of supplemental income. One of the main arguments against measures to reduce the demand for tobacco is the worry that falling demand will cause job losses in the farm sector. Tobacco is a good source of indirect income for smallholder farm households with family members who work as wage-laborers on large-scale commercial tobacco farms. Simple calculations suggest that the total wage bill for tobacco grown on LSC farms is around USD 47.3 million. To the extent that a share of this income is sent as remittance payments to family members in communal areas, tobacco can play a major role in helping to finance the inputs needed for improved management of major smallholder crops including maize and cotton. In countries where most of the tobacco crop is consumed domestically, expenditure switching will create demand for other goods and services, and employment gains in these other sectors are likely to offset the losses in the tobacco sector.

For A. formosa, the most substantial expression difference occurred between DS3 and DS4, although the number of genes DE between DS4 and DS5 is also relatively high . This pattern more or less mirrors our sampling strategy in which finer sampling intervals were used between DS1 and DS4 with a larger developmental gap between DS4 and DS5. Given that there are relatively few changes across the earlier stages, for our first global analysis we focused on the end points of our sampling, bracketing Phase I of development, and identified the genes that increase or decrease in expression between DS1 and DS5. Within each species, between 5568 and 6933 genes were differentially regulated between DS1 and DS5. Counts of genes commonly up- and down-regulated between species are presented in Fig. 3a. A set of 1262 genes was commonly up-regulated across all species through development while a set of 1094 genes was commonly down-regulated across all species through development . Between 498 and 644 genes were uniquely up-regulated in just a single species across development while between 459 and 683 genes were uniquely down-regulated in a single species across development . Gene Ontology enrichment analyses were conducted for the genes commonly up- and down-regulated between DS1 and DS5 in all taxa. Genes related to mitotic activity, including DNA replication, mitotic chromosome condensation, and microtubule ontologies are enriched early in development, while genes belonging to oxidation reduction and fatty acid biosynthetic ontologies are enriched late in development . The sets of genes up- or down-regulated in all of the spurred taxa but not A. ecalcarata were also identified,indoor vertical farming with 521 genes commonly up-regulated in only the spurred taxa between DS1 and DS5 and 318 genes commonly down-regulated between these stages .

Although the petal is generally not considered a photosynthetic organ, GO enrichment analyses on the gene sets DE in only the spurred taxa showed an enrichment of genes with GO terms related to photosynthesis were up-regulated between DS1 and DS5 . Looking across all four species, 11,258 genes showed differential expression between DS1 and DS5 in at least one species, representing a full third of predicted genes in the Aquilegia genome . Conducting a principal component analysis of the expression levels of these genes across all samples showed that most of the variance can be explained by developmental time point . According to PC1 , the comparative developmental staging done across each species is fairly consistent with the expression data across taxa with a few exceptions. The A. ecalcarata samples assigned to DS1 have slightly higher PC1 values than the DS1 samples from the other taxa, suggesting that based on gene transcription, they may be more developmentally similar to the DS2 samples from the other taxa. Judging by PC1, the A. chrysantha samples assigned to DS4 and DS5 may be more transcriptionally similar to DS3 and DS4, respectively, of the other three taxa.In order to identify genes potentially involved in nectar spur development, differentially expressed genes between spurless A. ecalcarata and each spurred taxon were identified at each developmental stage. 15,588 genes are differentially expressed between A. ecalcarata and at least one of the spurred species during at least one developmental time point . Across the first three developmental time points, a greater number of the genes identified as DE between A. ecalcarata and each spurred taxon are expressed at a higher level in A. ecalcarata than the spurred species . By the fourth and fifth developmental stages, an approximately equal number of DE genes are expressed more highly in A. ecalcarata and each spurred species. DE gene sets for each of the spurred species versus A. ecalcarata were then compared to each other to identify genes that are commonly up- or down regulated in the spurred taxa versus A. ecalcarata at each developmental stage .

At each developmental stage, more genes are commonly up-regulated in A. ecalcarata relative to all of the spurred species than up-regulated in all of the spurred species relative to A. ecalcarata. The number of genes commonly up-regulated in spurred taxa gradually increases throughout development . The number of DE genes up-regulated in A. ecalcarata also increases across development, but the greatest increases occur between DS1 and DS2 , and between DS4 and DS5 . In total, 237 genes are commonly up-regulated in the spurred taxa relative to A. ecalcarata at all five developmental stages and 453 genes are commonly up-regulated in A. ecalcarata versus the spurred taxa at all five developmental stages . As a comparison, we also looked at the number of loci that were commonly up- or down-regulated in any one of the spurred species relative to the other three taxa . There was a common pattern in that there were more genes up-regulated in the focal species of the comparison than down-regulated , however, more genes were commonly DE when A. ecalcarata was the focal species. Conducting PCA on the set of genes that were commonly DE between all spurred taxa and A. ecalcarata at any developmental time point shows, as expected, that PC1 captures the difference between the spurred species and A. ecalcarata while PC2 captures common developmental differences across species . PC3 largely captures differences between A. sibirica and the other taxa while PC4 largely captures differences between the two North American species, A. formosa and A. chrysantha. While data points for PCs 3 and 4 generally cluster by species, interestingly, the A. ecalcarata DS5 samples cluster with A. formosa in PC3 and with A. chrysantha in PC4, although we have no hypothesis for why this may be. At each developmental stage, we tested for GO enrichment in the genes identified as either having higher expression in A. ecalcarata or commonly having higher expression in the spurred taxa versus a set of genes expressed in any species at that developmental stage . During the earlier developmental stages , genes related to heme/iron binding and oxidoreductase activity are over-represented in the A. ecalcarata datasets. By DS5, many GO categories related to mitosis are enriched in the set of genes identified as significantly up-regulated in the spurred taxa.

A prior study sought to identify genes important for nectar spur development in the horticultural variety A. coerulea ‘Origami’ by comparing gene expression between two regions of developing petals: the distal tip of the developing nectar spur and the petal blade. A. coerulea ‘Origami’ has relatively long nectar spurs, similar to those of hawkmoth-pollinated species, and these comparisons between developing spur and blade were made at two developmental times points,hydroponic vertical farming when petals were 1 mm and 3 mm long. As this prior study was conducted using an earlier Aquilegia genome annotation, we re-analyzed the data using the A. coerulea “Golsdmith” v3.1 genome annotation . Counts of genes DE either developmentally or tissue specifically are summarized in Supplemental Tables S11 and S12 . Focusing on DE genes between the blade and spur cup tissue, at the 1mm stage, 490 genes were more highly expressed in the blade and 280 genes were more highly expressed in the spur cup . At the 3 mm stage, 1178 genes were more highly expressed in the blade and 767 genes were more highly expressed in the spur cup . The results of this reanalysis are quite similar to the original analysis and exhibit a pattern common to that seen in the comparison of A. ecalcarata to the spurred taxa at early stages : more genes were commonly up-regulated at both the 1 mm and 3 mm stages in the spurless tissue sample than in the sample with spur tissue . These DE gene sets were compared to the lists of genes commonly DE between the spurred taxa and A. ecalcarata at roughly comparable developmental stages . Since A. ecalcarata petals consist primarily of blade tissue, we hypothesized that there would be more genes commonly up-regulated between whole A. ecalcarata petals and the A. coerulea ‘Origami’ blade tissue , and between entire petals of the spurred taxa and the A. coerulea ‘Origami’ spur tissue , compared to the opposite combinations . This is indeed the case, however, there are some genes that are more highly expressed in the blade tissue and the spurred taxa or in the spur tissue and in A. ecalcarata . For the purposes of identifying genes that make up a potential core module for spur development, we were particularly interested in genes that fall into the ‘blade’ and ‘spur’ classes defined above. Comparing genes that are more highly expressed in A. ecalcarata than the spurred taxa at all developmental stages to those that are expressed more highly in the blade than the spur at both the 1mm and 3mm time point reveals only 27 common genes . Looking at the intersect of genes that are more highly expressed in all of the spurred taxa at the stages we assessed with those that are expressed higher in the developing spur at both the 1 mm and 3 mm stages reveals an even smaller set of only 8 common genes . Of the 8 genes more highly expressed in ‘spur’ class, four show a general trend of decreasing through development in the spurred taxa,especially between DS4 and DS5 . These genes encode a dynein light chain protein, a myb/SANT-like transcription factor, a cytochrome P450 protein, and an oxysterol-binding protein. Two genes, encoding a leucine rich repeat protein and a heat shock factor transcription factor, show a pattern of increasing expression in the early stages assessed followed by a decrease, while another gene encoding a C2H2-type zinc finger transcription factor has more steady expression throughout development. One gene, encoding a xyloglucan endotransglycosylase protein, has relatively low expression in the early developmental stages with an uptick in expression moving into DS5 in the spurred taxa, especially in A. sibirica and A. formosa.

Interestingly, the STY homologs, which were among the most strongly differentially expressed loci in the blade to cup comparison and which were later found to be critical to nectary development, were not among the genes overlapping with the spurred to unspurred comparison. During later stages of petal development, however, there is some divergence between the STY homolog expression among the species sampled here, with A. ecalcarata showing lower expression than the other three . Among the 27 genes that are more highly expressed in the ‘blade’ class, several transcription factors stand out. These include a gene in the NAC transcription factor family with similarity to ANAC034 , an OVATE Family Protein with similarity to AtOFP4, and a gene with homology to the cryptochrome 2-interacting basic helixloop-helix transcription factor AtCIB1 .In Arabidopsis, many genetic factors have been identified that influence petal shape. These often function by regulating the timing of the transition from cell proliferation to cell differentiation . Genes identified as playing a role in controlling this transition can broadly be broken down into those that promote proliferation versus those that repress proliferation. The cell proliferation activators start off broadly expressed across the primordium but they become down-regulated in a basipetal wave that is complementary to an opposing pattern of up-regulation of the cell proliferation repressors. As the early phase of nectar spur development in Aquilegia involves prolonging localized cell divisions in the spur, we explored the expression of the Aquilegia homologs to these Arabidopsis candidates in our dataset to see if their expression patterns are generally consistent with a conserved role in Aquilegia petal development or differ between A. ecalcarata and the spurred taxa.Negative regulators of cell proliferation in A. thaliana petals include BIG BROTHER , DA1, the TCP genes TCP4 and TCP5, and the cyclin-dependent kinase inhibitor genes KIP RELATED PROTEIN 4and KRP2 . Although it may be expected that these genes would show the opposite pattern of expression from the cell-proliferation promoters, only a few of the Aquilegia homologs showed a pattern of increasing expression approaching DS5 . Two KRP-like genes, AqKRP2-like and AqKRP-like showed a strong increase in expression, especially between DS4 and DS5. Both of theses genes were also expressed more highly in A. ecalcarata than the spurred taxa. A third KRP-like gene with homology to KRP4 actually sharply decreased in expression during later developmental stages in all taxa assessed. Aside from the two KRP-like genes previously mentioned, AqDA1 is the only other candidate cell division repressor that appears to be increasing in expression toward DS5.

Chapter 3 examines one piece of environmental management that needs to be addressed for deep-seabed mining: biodiversity assessment and monitoring. Multiple approaches are available to conduct biodiversity assessment and monitoring, such as morphology-based taxonomy and metabarcoding . The former involves an expert handpicking organisms out of an environmental sample and identifying them by eye or with the aid of a microscope. The latter involves chemical processing, molecular sequencing, and bio-informatics. Each of these methods are associated with scientific advantages and disadvantages, including how well they inform ecosystem services, and specific economic costs. In addition to discussing these scientific trade offs, Chapter 3 compares their cost-effectiveness in identifying deep-sea organisms, which is relevant to decision-makers when considering assessment and monitoring requirements. Another approach often employed in deep-sea research is the use of remotely-operated vehicles to survey and collect samples, including a wealth of imagery data. In the summer of 2015, Ocean Exploration Trust completed an expedition to explore the southern California borderlands, which included ROV dives at several methane seeps on the continental margin . Methane seeps are habitats where hydrocarbons and other fluids escape from the seafloor, fueling a biological community based on chemosynthesis . In a widely food-limited environment,indoor growers elevated primary production could significantly influence adjacent areas . Chapter 4 uses ROV dive videos from three methane seeps to demonstrate how deep-sea imagery can be used for characterization of ecosystem services. More specifically, Chapter 4 focuses on fisheries services and climate regulating services related to carbon, which have previously been documented at a California methane seep .

It provides the first detailed biological description of two methane seeps, and is the first application of an ecosystem services-based trait approach in the deep sea.Ecosystem services can also be generated by built ecosystems, such as natural storm water treatment systems . NTS are human-made installations that are designed to capture and treat storm water runoff using physical and biological processes . Coastal development and urbanization have altered water flows and introduced contaminants into runoff, which can cause flooding of infrastructure and pollution of local water . NTS provide a low-impact strategy to address these issues by slowing water flows, removing contaminants, and storing runoff for possible reuse . In southern California, where there is a discrepancy between water supply and demand, NTS are becoming more widespread . Chapter 5 reviews potential ecosystem services associated with NTS, such as targeted water infiltration and pollutant removal as well as non-targeted pollination, climate regulation, aesthetic value, and pests . Examples from Los Angeles County illustrate these ecosystem services and practical methods are suggested to begin quantifying and economically valuating them. Chapter 6 investigates one ecosystem service associated with NTS: climate regulation related to carbon. Vegetation within NTS, such as bio-filters and bio-swales, uptake atmospheric carbon dioxide through photosynthesis and can store it as biomass or in soil. Plant and soil respiration, the reverse process that releases carbon back into the atmosphere, is dependent on environmental characteristics such as soil moisture and soil temperature . Chapter 6 provides measurements of carbon fluxes over NTS, in comparison to other urban land uses in San Diego : grass lawns, horticultural gardens, and natural coastal sage scrub.

Data envelopment analysis is used to compare carbon efficiency, i.e. how well each system converts its given environmental characteristics into desirable carbon fluxes. This analysis incorporates both environmental inputs and outputs, which may be helpful when considering urban management strategies. The final chapter of this dissertation summarizes the lessons learned from applying an ecosystem services perspective in multiple systems using multiple approaches. It also provides recommendations for incorporating ecosystem services into environmental decision-making and management.Deep-seabed mining is an emerging industry that could begin commercial production in the near future. It has potential to alter habitats targeted for minerals through physical disturbance, removal of substrate, sediment resuspension and deposition, light, and noise . The International Seabed Authority , the body governing the international seabed and its resources , is tasked with developing rules, regulations, and policies, including those that will “[protect] the marine environment from harmful effects” and “[prevent] damage to the flora and fauna of the marine environment” . This obligation highlights the need for two tasks: establishing a baseline level of biodiversity for potentially impacted areas, and monitoring changes in biodiversity due to mining activities against that baseline. Deep-sea biodiversity supports a range of ecological functions and ecosystem services, such as fish catch, genetic resources for industrial and pharmaceutical products, carbon sequestration and storage, and nutrient cycling . The Clarion-Clipperton Fracture Zone is an abyssal plain area, ranging from approximately 3900-5500 m in depth, that hosts high densities of polymetallic nodules targeted for mining of copper, nickel, and cobalt. The CCZ has 30 exploration claims, each up to 75,000 square kilometers.

It also contains a wealth of biodiversity, some associated with the nodules themselves . Pilot studies and mining simulations have found little recovery of Pacific abyssal plain habitats post-disturbance within 26 years . Common megafaunal taxa in the CCZ include ophuiroids, xenophyphores, and corals, which are found in higher densities in the CCZ relative to other abyssal plain sites . Sediment macro- and meiofauna dominate eukaryotic species richness and densities on the abyssal plains , and include foraminifera, nematodes, polychaetes, isopods, and tanaids . While current ISA draft regulation for commercial exploitation of the Area acknowledges biodiversity as something to measure, the measurement approaches are not specified. Biodiversity can be measured in a variety of ways: number of species in an area, species absolute and relative densities, number of functional roles in a system and species interactions, genetic variation between and among populations, representation of phylogenetic lineages, and number of habitats and ecosystems . Current faunal bio-monitoring programs generally employ morphology-based taxonomy , which requires an expert to manually sort and identify hundreds to thousands of individual organisms. As a result, taxonomic studies in the CCZ require a lot of resources . The spatial heterogeneity of the CCZ biological community necessitates robust biodiversity assessment and monitoring . Large taxonomic gaps in deep-sea benthic communities still exist despite scientists working tirelessly to identify known species and describe new ones. As a result, MBT is limited to animal taxa that not only exhibit distinguishing morphological features , but also those for which expert taxonomists exist. Furthermore, this expertise can be especially difficult to find for deep-sea taxa and, as a result, much of the deep-sea environment remains undescribed . MBT is strongly limited by the amount of time and cost required to generate data, and the lack of taxonomic expertise that limits the breadth of biodiversity it can cover. This severely hampers scaling up both temporal and spatial resolution, and prevents timely adaptive management measures. Although MBT is necessary in order to describe new species , emerging molecular tools can serve to rapidly document biodiversity. Molecular techniques, such as metabarcoding and metagenomics,danish trolley provide a rapid alternative for biodiversity measurements in natural systems . Technical advances have increased our capacity to generate biodiversity data, by moving from DNA extracted from a single individual to environmental DNA obtained from an environmental sample in order to rapidly assess whole biological communities. Here, we focus on the application of metabarcoding: the sequencing of specific genes, used for taxonomic identification, in an environmental sample . A mix of both morphology-based and molecular-based methodologies are advocated to build robust and extended biodiversity inventories in the CCZ .

An example of a combined workflow couples morphological identification of individuals with DNA sequencing . While initially labor-intensive, this combined approach to taxonomy can facilitate later environmental assessment and monitoring by reducing the need for morphological identification as more species are described and sequenced. Additionally, a combined approach can promote standardization for data comparison among CCZ claims. For example, contractors measuring biodiversity within their own claims may be identifying the same species differently from other contractors. With a physical specimen associated with a genetic sequence, this issue could be more readily resolved even without a formal species description. Another example of a combined approach is initial genetic screening of large swaths of the CCZ to prioritize areas of interest for more detailed morphology work. It is likely that a combination of techniques is necessary in order to obtain scientifically robust data for environmental baseline and monitoring requirements set by UNCLOS and the ISA, such as those related to abundance and biomass, and genetic connectivity . This paper aims to evaluate scientific and economic trade offs between MBT and metabarcoding of small eukaryotes in the context of deep-sea biodiversity assessment and monitoring. Specifically, we discuss MBT and metabarcoding for evaluation of deep-seabed mining impacts in the CCZ, where interest in polymetallic nodules is high , small and rare taxa are dominant , and patchiness is substantial . We consider scientific trade offs between approaches in relation to environmental assessment and monitoring objectives, as well as how a combined approach can mitigate each method’s weaknesses. Decision networks are constructed for each methodology to highlight how decisions within each approach can affect scientific outcomes and economic costs. Lastly, we assess and compare direct and indirect costs associated with each methodology in a cost-effectiveness framework.Both MBT and metabarcoding techniques are framed here as a series of choices within a workflow that can influence both scientific outcomes and economic costs. We surveyed deep-sea experts and published protocols in order to determine the steps within each methodology, and how the choices within those steps affect scientific outcomes. In most cases, scientific questions and desired outcomes dictate how choices are made, creating a range of appropriate protocols so only general steps are listed in the results.Cost-effectiveness analysis is an economic approach that evaluates outcomes and their associated costs . An action or policy can be considered “cost effective” if it is the least costly to obtain a desired outcome, or it generates the best outcome given fixed resources. CEA differs from cost-benefit analysis because, rather than answering whether an action should be taken or not, it ranks strategies to maximize their efficiency . Posed with the question of how the ISA and contractors can meet environmental requirements, CEA can facilitate choosing which methods, or combination of methods, are most least-cost cost-effective. For each methodology, experts and published protocols provided estimates of the consumables used and number of work hours taken in order to generate taxonomic data. Total cost is the sum of consumable and labor costs. Fixed costs, such as laboratory equipment and bio-informatics pipelines, were not included in our analysis. Quantity of consumables were summed. Prices were taken directly from supplier websites, and are likely an overestimate because many research institutions receive discounted prices. Common suppliers in the U.S. were used: Fisher Scientific, VWR, and Qiagen, and prices were averaged among them. Labor costs came from best estimates of work hours .In our model, output is the number of “operational species” identified. “Operational species,” or proxies for species, are commonly used in biodiversity assessments because sampled deep-sea organisms are often new to science . MBT can employ morphospecies, individuals grouped together solely by morphology, whereas molecular methods use operational taxonomic units to distinguish species . Using operational species is less costly than describing every new species discovered, which involves writing a detailed morphological description and designating a holotype.Combining morphological and genetic operational species may circumvent the need for formal species descriptions and provide a standard unit of outcome that is relevant to both decision-making and our analysis. To approximate sampling regimes in the CCZ, we looked at a subset of published studies that attempt to characterize CCZ biodiversity of sediment eukaryotes using either MBT or molecular methods . Details from their sampling designs were extracted , as well as their relevant results . This information was used to make more appropriate comparisons between MBT and metabarcoding.Scientific trade offs should be considered while comparing MBT and metabarcoding, including what data are generated and information gained from their interpretation. These are summarized in Table 3.1 and discussed below. CCZ biodiversity is dominated by small and rare eukaryotes , which may favor taking a molecular approach to biodiversity assessments. However, although there is limited deep-sea taxonomic expertise, there is also little robust genetic information on CCZ fauna.

In pre-agricultural societies, zoonotic disease disproportionately affected those who came into contact with animals and their products during hunting and gathering. In Neolithic and post-Neolithic European and Middle Eastern societies, conversely, a greater proportion of individuals came into close contact with concentrated animal pens and therefore became more liable to infection from diseases that followed their byproducts.As Polgar has shown, indeed, the domestication of animals has historically increased the spread of zoonotic diseases including anthrax, tuberculosis, and even types of influenza. Students and researchers should consider the paleo-archeological insights above as they try to understand why Native Americans were often so vehement in their immediate opposition to European agricultural models that concentrated cattle in farms and/or stored grain in newly constructed central warehouses. The development of those models, after all, accompanied the growth of massive disease outbreaks among Native Americans from the 1500s. The primary historical sources unearthed in the work of Anderson and Cronon, for example, would provide one point of reference: in New England, enclosed farms set up by seventeenth-century English settlers seemed to encourage the spread of infectious diseases, whether zoonotically or due to the increased concentrations of peoples.Bovine strains of tuberculosis arrived with European cattle, as did tuberculosis bacilli and influenza strains in Swine,raspberry cultivation pot as well as the trichina worm.Spanish settlers in California and the Southwest created ranches with similar effects, albeit in a slightly different colonial context.

Native Americans, according to one 1674 colonial report, perceived English cattle as “Unwholsom for their Bodies, filling them with sundry Diseases.” As Anderson has suggested in a discussion of human diseases that seemed to correlate with animal outbreaks, those Native Americans “who survived an initial bout of disease often emerged in a weakened state, vulnerable to subsequent ailments that would not necessarily have imperiled a healthy individual.”New England Native Americans caught up in King Philip’s War often “began their hostilities with plundering and destroying cattle,” according to one witness. Large-scale killings of domestic animals continued throughout the war, and Native American hostility to the animals – and their owners – extended to mutilation and torture of cows in particular.Assessing the imposition of domesticated agriculture by Europeans during early contact, Cherokee-American anthropologist and historian Russell Thornton has thus suggested that “the reasons for the relatively few infectious diseases in this [western] hemisphere [prior to European contact] surely include… the existence of fewer domesticated animals, from which many human diseases arise” – unlike those that later grew up due to grain storage and transit patterns which differed from hunter-gatherer lifestyles as well as their own pre-contact forms of land management and crop cultivation.As biological anthropologists have shown, some precontact Native American communities were likely familiar with the association between cultivated animal lots and disease, albeit in more isolated settings. Pueblo Native Americans had witnessed the spread of diseases in areas contaminated by turkey dung, most probably salmonella and Shigella.Turkeys had been domesticated in the northern Southwest, likely from populations of Merriam’s wild turkey. In most cases Pueblo communities demonstrated the capacity for mixed land use between animals and cultivated crops, without zoonotic diseases. But their example at least suggests that some communities may have been aware of the potential disease association, if conditions became less optimal.

To be sure, there remain significant risks in using a conceptual distinction between Paleolithic hunter-gatherers and Neolithic agriculturalists to understand changing Native American health outcomes after European contact. The link between negative Native American responses to European domesticated farming and the problematic health patterns associated with Neolithic agriculture must not be emphasized too specifically, of course; not least because the latter occurred between 8,000 and 10,000 years prior to the Native American encounter with colonial-European agriculture. Yet it is at least possible to draw broad conceptual associations between the two studied periods. Just as in paleo-archaeological records detailing the rise of Neolithic grain production and animal husbandry, source material relating to the Native American-European encounter demonstrates the potential for zoonotic diseases to proliferate in regions that were required to adapt to more concentrated forms of land use . Rather than highlighting a simple biological exchange of disease, then, students could point to the specific interventions of European enclosure and domesticated cattle-raising, which made infectious maladies even more potent and widespread.They would consider the methodologies and conclusions of Armelagos, as well as those provided by other scholars of the move from Paleolithic ecology towards Neolithic agriculture. Having done so, they would be in a position to draw general inferences – and even conclusions – as they assess historical source material for the Native-American-European encounter and the growth of zoonotic diseases, over a relatively wide geographical basis and a relatively broad space of time. The purported difference between Native American hunter-gatherers and European pastoralists becomes rather more problematic if it is used to de-emphasize the role of indigenous agriculture and formal crop cultivation prior to European contact. In order to avoid such a crude assertion, students would do well to assess our developing understanding of the “Hopewell tradition”, which describes the various aspects of the Native American cultures that developed along rivers in the northeastern and Midwestern United States from 200 BCE to 500 CE.

In these regions, tropical domesticate species of gourds, such as Cucurbita pepo, were introduced from Mesoamerica, well before the 2000 to 1000B.C period that scholars once linked to the first domestication of North American plants in the region. Scholars have recognized Curcurbita at the subspecies level and have thus made the convincing suggestion that the Hopewell cultures of North America created a second independent center of domestication for the species, just as they did with other plant species: Pumpkins, marrows, and other gourds were first domesticated in Mesoamerica, while acorn squashes, scallop squashes, fordhooks, crooknecks,low round pots and a variety of gourd species were then cultivated in North America. The domestication of indigenous eastern North American seed plants can thus be categorized in four species: Cucurbita pepo, Helianthus annuus, Iva annua, and Chenopodium berlandieri.During the summer and fall periods, for example, pseudo grain seed-like chenopods became an important starch source for some Native Americans from modern-day Arkansas to eastern Kentucky, at latitudes from northern Alabama to central Ohio, from ca. 1800 B.C. until ca. A.D. 900 or later. Evidence suggests that hunter-gathering practices in these regions were supplemented by the domestication of those and similar chenopods .Thus it is increasingly clear that many North American societies modified parts of their ecological environments even prior to the proliferation of maize production. The latter responded to demographic distress on the one hand, but also may have contributed to certain declining health outcomes, on the other hand . The four indigenous species that were cultivated prior to and even after the introduction of maize, conversely, were likely the product of a much larger context of “stable long-term adaptations and broadscale niche construction efforts that were carried out in the absence of any carrying-capacity challenges or seriously compressed and compromised resource catchment areas.” Their cultivation, alongside other “crops” such as berries and tubers, had required, among other things: differential culling of trees, expanding natural strands of floodplain seed plants, artificial fires, and establishing “orchards” of fruit and berry-producing species.Similar patterns of cultivation could also be detected in other regions, such as California and the American Southwest, as well as the wild rice regions of the central Great Lakes . In 1541, in what is modern-day eastern Texas and western Louisiana, Spanish colonizers such as Hernando de Soto noted that communities of Karanka was cultivated corn, beans, squash, sunflowers, and tobacco.From around A.D. 900 in the riverine “horticultural villages” on the Great Plains, along the Missouri and its tributary rivers flowing into the lower Mississippi, beans, squash, melon, corn, and sunflowers were cultivated by Caddoan speaking Native American communities. Each village also maintained hunting territories where animals were stalked from the late-summer onwards. Thus, here and elsewhere, it is inaccurate to highlight a dichotomy between indigenous horticulture and hunter-gatherer patterns prior to the period of first European contact.Precontact horticultural communities often “retained hunting and gathering practices as regular supplements and insurance against occasional shortages.”After European contact, to be sure, many North American horticulturalists tried to revert to “full time hunting and gathering” as a means for sustenance; even while some in New England, among the Cherokee of the South, and the Navajo of the Southwest, remained as pastoralists.Greater reliance on hunting and gathering after contact represented an indigenous response to the curtailment of horticulture, or its problematic limitation and enclosure, by new European forms of crop rotation and animal husbandry. That response, however, set up a chain of circumstances that resulted in the permanent loss of autonomous access to hunted meats and indigenously cultivated plants by the second half of the nineteenth century. From the late-sixteenth century, Spanish, French, and English settlers in coastal North America tended to overlook the possibility for symbiosis between hunter-gatherer and horticultural methods of sustenance, which often oscillated in relative importance according to the season.

Instead, Europeans noted the Native-American reaction to their presence – a reversion to hunting and gathering and revulsion for their own domesticated agriculture – and erroneously assumed that they solely engaged in nomadic hunting patterns. This attitude “contributed to the notion that removal of eastern nations to Midwestern reservations would solve problems of conflict between expanding Euro-American populations and the Indians’ loss of hunting lands.” Among English colonizers in the eastern seaboard, the view that Native Americans refrained from land cultivation was indeed key in defining the territory as res nullious – empty of privately managed land and thus legitimate for colonial settlement. A similar assessment took place among Spanish colonizers in present-day California and the Southwest, albeit on a different scale.As they moved towards an increasingly central migration trajectory in the face of European colonization, various indigenous communities from the East, the Great Lakes, and the West often adopted European firearms and horses to hunt in new nomadic patterns. Shoshone tribes from the central and northern Mountain West adopted Spanish horses and introduced them to other indigenous communities in the Great Plains. Algonquians such as the Blackfeet, Gros Ventres, and Araphos, as well as some Cree and Ojibwa tribes, “abandoned forest hunting and gathering to become mounted nomadic hunters on the Great Plains” – thereby interacting with other tribes who had adopted Spanish horses as a means to hunt for new food sources. A northern Athapaskan group, the Sarsis, as well as some Comanches, similarly adopted horse nomadism. By the later-eighteenth century, previously horticultural Cheyenne communities entered the Plains, coming to rely on hunted buffalo and bison. Siouan and Caddoan horticulturalists along the streams and rivers of the eastern Great Plains sometimes also switched to horse-nomadic hunting-gathering practices after their traditional forms of plant cultivation and hunting were threatened by the interaction between European settlement and Native American warfare. Pawnee Indians, as well as some Hidatsas on the upper Missouri, moved towards horse-mounted nomadism. Through the eighteenth century, Siouan-speaking tribes gravitated from horticulture towards bison hunting, shifting west and leaving the bottomlands of the Ohio and Mississippi rivers. In most of these cases, as Snow has pointed out, “people were not just responding to the attraction of nomadic hunting. There were by this time [around 1700] also strong direct and indirect pressures from the east, brought on by European settlement and expansion.” Initially, health profiles seemed to increase among various new Plains Native American communities. As Heckel has argued, using data from births between the 1830s and 1870s on the Great Plains, their new proximity to bison and other animals likely benefited the association between greater height and nutritional density. Yet as these communities adopted new forms of hunting, competition with European settlers in the region coupled with over efficiency so as to diminish their access to the area’s sources of animal protein and fat. By the later part of the nineteenth century, therefore, many Native Americans found themselves unable to rely on traditional nutritional interactions between horticultural and hunter-gathering products. Worse, they soon began to lose access to micro-nutrients and macro-nutrients from fast diminishing populations of bison. Relative to other European settlers, indeed, their height advantage diminished somewhat.The narrative above raises further implications for students and researchers, beyond the issue of zoonotic disease and concentrated settlements: if hunting and gathering as well as indigenous forms of crop cultivation were disrupted by the imposition of European agriculture in North America from the late-1500s, how else can we measure the historical symptoms and effects of declining health following the change to the Native American ecological landscape?

The intermittent water seals treatment was applied using a temporary sprinkler system installed in the plots following fumigation and the post fumigation tillage operation; water was applied four times in the first 2 days after fumigation: 0.5 inch after 3 hours, 0.2 inch after 12 hours, 0.2 inch after 24 hours and 0.2 inch after 48 hours. All plastic films were removed 10 days after fumigation. Fourteen days after the initial 1,3-D fumigation, the metam sodium treatment was applied through sprinklers at 160 pounds per acre in 2.75 inches of water. For the dual application treatment, 21 days after the initial treatment, soil was inverted with a moldboard plow and an additional 1,3-D treatment was applied with the previously described Telone rig and rolling operation. Fumigant emissions from eight 1,3-D treatments — two application shank types times four surface seal methods — were monitored in three replicate plots for 10 days following the initial application. Emission of 1,3-D from the soil surface was monitored using previously described dynamic flux chamber techniques . Briefly, a flow-through flux chamber with a 10-inch-by-20-inch opening was installed on the surface following fumigant injection and installation of the films or after the initial water seal treatment . These chambers allow semi-automated,fodder systems for cattle continuous sampling of fumigant concentrations in the air above the surfaces. The cis– and trans-isomers of 1,3-D were trapped in charcoal sampling tubes .

The two 1,3-D isomers were summed as total 1,3-D for data analysis and reporting. Individual tubes were removed from the flux chambers every 3 to 6 hours and stored frozen until laboratory processing. Emission flux and cumulative emission during the 10-day monitoring period were calculated based on surface area and air flow rates through the flux chambers, and treatment differences were compared using analysis of variance . The concentration of 1,3-D in the soil-gas phase was determined 6, 12, 24, 48, 120 and 240 hours after treatment. At each time point, samples were collected using a multi-port sampling probe and a system of gas-tight syringes to draw air from eight depths through charcoal sampling tubes. Samples were stored frozen until analysis. In the laboratory, all samples were processed using procedures described by Gao et al. . Briefly, sample tubes were broken and trapped fumigants were extracted from the trapping matrix with ethyl acetate and analyzed using a gas chromatograph equipped with a micro electron capture detector .Pest control efficacy was evaluated using citrus nematode bio-assay counts, fungal dilution plating, and weed emergence counts and biomass collections from each replicated plot. The pest control data from this research station emission flux experiment were reported in Jhala et al. .In addition to the emission flux and efficacy study conducted at KAC, two field trials were conducted in commercial nurseries to evaluate pest control efficacy and nursery stock productivity. Fumigation and surface treatments in the nursery experiments were the same as in the flux study with minor exceptions. The commercial nursery trials were arranged as randomized complete block experiments with a split plot arrangement of 1,3-D treatments.

The whole plot factor was surface treatment, and the split plot factor was the shank type. Individual plots in these experiments were 22 feet by 90 feet, and each treatment was replicated four times.In 2007, the experiment was established in a garden rose nursery near Wasco. The soil at the rose nursery site was a McFarland loam with pH 6.2, 0.9% organic matter and 74% sand, 13% silt and 13% clay. Treatments were applied on Nov. 7, 2007, when the soil temperature was 64ºF and soil moisture averaged 9.2% w/w from 2 to 5 feet. The experiment was repeated in 2008 in a deciduous tree nursery near Hickman, in a Whitney and Rocklin sandy loam soil with pH 6.5, 0.8% organic matter, and 66% sand, 23% silt and 11% clay. Treatments in the tree nursery trial were applied on Aug. 13, 2008, when the soil was 80ºF and soil moisture ranged from 5.0% to 12.6% w/w in the top 5 feet. Immediately following 1,3-D application, a disk and roller were used to compact the soil and disrupt shank traces and HDPE and VIF were installed using the Noble plow rig. For the water seal main plots, a temporary sprinkler system was installed after the post fumigation tillage operation and intermittent water seals were applied: 0.5 inch after 3 hours, and 0.2 inch each after 12, 24 and 48 hours. The dual application 1,3-D treatments were applied in the garden rose experiment on Nov. 28, 2007, but were not included in the 2008 tree nursery experiment. Metam sodium was applied in 2.75 inches of irrigation water through sprinklers 14 to 30 days after the initial 1,3-D treatment in both experiments.Both nursery trials were managed by the cooperating growers using their standard practices for planting, fertilization, in-season tillage and budding and harvest operations. In the 2007 rose experiment, two rows each of the rose rootstock ‘Dr. Huey’ and the own-rooted garden rose variety ‘Home Run’ were planted as hardwood cuttings in December 2007.

Rose nursery stock was planted 7 inches apart in furrows spaced 3 feet apart, and the field was furrow irrigated during the 2008 and 2009 growing seasons. The own-rooted cultivar was harvested after one growing season in January 2009, and the unbudded ‘Dr. Huey’ root stock was harvested in February 2010 after an additional growing season. At both harvest dates, all plants in one 90-foot row were lifted using a single row undercutting digger, plants were bundled and tagged by plot, and graded in a commercial packinghouse. In the 2008 tree nursery trial, two rows each of the peach root stock ‘Nemaguard’ and the plum root stock ‘Myro 29C’ were planted with 8 inches between plants and 5 feet between rows in December 2008. The tree nursery plots were sprinkler irrigated during the 2009 growing season. Due to the market needs of the cooperating nursery,fodder sprouting system the root stocks in the tree trial were not available for harvest and grading as a part of the experiment. Pest control efficacy and crop productivity were evaluated during the 12- or 26-month nursery production cycle. Nematode control was determined using a citrus nematode bioassay in which two sets of muslin bags containing 100 grams of soil infested with citrus nematode were buried at 6, 12, 24 and 36 inches below the soil surface in each plot prior to fumigation. The initial population of citrus nematodes in infested soil was 4,086 and 3,876 nematodes per 100 cubic centimeters of soil in 2007 and 2008, respectively. The bags were recovered 1 month after fumigation, nematodes were extracted from 100 cubic centimeters of soil using the Baermann funnel protocol, and surviving nematodes were identified and counted. To evaluate the effect of fumigation treatments on soil fungal populations, ten 1-inch-by-12-inch soil cores were collected from each subplot 2 weeks after fumigation. Soils were homogenized, and a sub-sample was assayed for Fusarium oxysporum Schlecht. and Pythium species using dilution plating techniques on selective media. Pythium species samples were plated on P5ARP medium for 48 hours, and F. oxysporum samples were plated on Komada’s medium for 6 days. Emerged weeds in a 1-square-meter area were identified and counted twice in the winter following the fall fumigation and several times during the subsequent summer growing season. Nursery stock establishment, vigor and growth were monitored during the season. Visual evaluations of crop vigor were made on a scale of 1 to 7, where 7 was the most vigorous and 1 was dead or dying plants. Near the end of the growing season, trunk diameter of 10 plants in each subplot was measured 3 inches above the soil surface using a dial caliper. As previously described, rose nursery stock was harvested and graded to commercial standards ratings, but tree nursery stock was not harvested as a part of the experiment.

Data were subjected to analysis of variance, and initial analyses indicated that the shank types did not differ in their effect on any of the pest control or crop growth parameters measured. Thus, data from the two shank type treatments were grouped together within surface treatments and reanalyzed with seven treatments and six treatments . The nematode, pathogen and weed density data were transformed [ln ] to stabilize the variance prior to analysis; however, means of untransformed data are presented for clarity. Treatment means were separated using Fisher’s protected least significant difference procedure with α = 0.05.Within a surface treatment, there were no statistical differences in emission flux between the two application shank types, thus data were combined over application rig. However, significant differences in 1,3-D emission flux were observed among surface treatments . Fumigant emission flux from bare plots was two times higher than from water seals and HDPE and nearly 15 times higher than from VIF within 48 hours after treatment. Emission from water-sealed plots was reduced during the sequential water applications, but flux was similar to bare soil plots after 48 hours. HDPE film continued to give lower emission rates than the bare soil and water seals but was significantly higher than VIF. Throughout the monitoring period, VIF-covered plots had the lowest 1,3-D emissions; maximum flux was 11 micrograms per square meter per second , which was at least 90% lower than that from the bare soil plots. Relative to the bare soil treatment, estimated cumulative 1,3-D emission losses for water seals, HDPE and VIF were 73%, 45% and 6%, respectively, which were similar to reports from a previous field study .Concentration of 1,3-D immediately below the plastic film indicated that 1,3-D retention is much greater under VIF film than under HDPE . Several other studies have shown that VIF can retain substantially higher fumigant concentrations without negatively affecting nematode, pathogen and weed control efficacy or crop yield .Initial analysis of fumigant distribution in the surface 90 centimeters indicated that there were no differences between the application shanks within a surface treatment in this zone; thus data were combined over application shank types . The 1,3-D concentration was highest near the injection depth, at 45 centimeters and lowest near the soil surface, at 5 centimeters , and at 90 centimeters , but this difference diminished over time. The effect of depth on 1,3,-D concentration was most evident in water seals and bare soil plots. HDPE and VIF plots had more uniform distribution of the fumigant through the soil profile than the water seals plots, especially 48 hours after treatment. However, 1,3-D concentration under the VIF tarp was markedly higher than in all other treatments, which suggests that there could also be differences in the top 5 centimeters of soil. These results imply that the use of a highly impermeable tarp can lead to a more uniform distribution of fumigants in the soil profile and may allow satisfactory pest control with reduced application rates .Pest control data from the 2007 KAC emissions trial and a related 2008 emissions trial were reported previously and are not shown here. In general, however, there were few differences in pest control attributed to the fumigant application shanks used in the trial. Pythium species populations were lower in all treatments than in the untreated control, but no statistical differences were noted in Fusarium species populations among treatments. The high 1,3-D rates and well-prepared soils resulted in complete control of citrus nematodes in the bio-assay bags in all treatments and depths. Weed populations were variable among treatments but tended to be lowest in methyl bromide plots and 1,3-D plots sealed with VIF and highest in the water seals and dual 1,3-D application treatments. All treatments of 1,3-D or methyl bromide effectively controlled citrus nematodes in bio-assay bags buried at 12-, 24- and 36-inch depths in each plot. However, these results, which were obtained in well-prepared sandy soils with low pest and pathogen populations, may not apply to more challenging field conditions . Applications of 1,3-D sealed with HDPE or VIF and dual application 1,3-D treatments reduced Fusarium and Pythium species propagules in the soil compared with the untreated plots . These treatments were comparable to methyl bromide in controlling Fusarium and Pythium species.