Nature Ecrogrow

Diet composition also influences the aging process, with low protein diets and high phytochemical intake being associated with a longer lifespan. Notably, a recent analysis suggests that the heritability of human longevity is below 10%, indicating that lifestyle choices play a major role in influencing aging and longevity. Since interventions such as CR and dieting are difficult to implement and maintain over a long period, interest has focused on identifying molecules that produce effects similar to CR . This endeavor is based on the observation that signaling pathways that are modulated by CR, including 5’ adenosine-monophosphate-activated protein kinase , mammalian target of rapamycin and sirtuin-1, can be targeted by small organic compounds. Activation of these pathways induces autophagy, mitochondrial biogenesis and expression of antioxidant and detoxifying enzymes, which together can improve cellular function. In a manner similar to CR, several organic compounds labeled as CR mimetics promote physiological functions and reduce the developmentof chronic diseases, thus improving both health and longevity. One of the main advantages of C. elegans is its short lifespan of about 20 to 25 days, allowing the rapid screening of substances that affect longevity. In addition, nematodes can be manipulated easily and single-gene deletion mutants are readily available, which facilitates the identification of signaling pathways involved in lifespan extension. Furthermore, round flower buckets many cellular pathways that control aging in C. elegans are conserved in more complex organisms, including fruit flies, mice and humans.

Modulation of the gut microbiota can also positively or negatively influence health and longevity in C. elegans. We review here the molecules and extracts derived from plants and fungi that are known to extend the lifespan of C. elegans, and discuss the possibility of using these substances in humans.A survey of the literature indicates that a large number of molecules and extracts from plants and fungi extend the lifespan of C. elegans . Many of these natural substances are consumed in the human diet, and are found in vegetables, fruits, mushrooms, spices, tea, coffee and wine, while other extracts are derived from herbal and fungal remedies used in traditional Chinese medicine . Some pharmaceutical drugs were originally derived from plants and fungi, such as acetylsalicylic acid , lovastatin and metformin, as well as molecules that were isolated from herbal remedies, including celastrol, huperzine A and triptolide . In addition, many of the plant and fungal extracts and molecules included here are used as dietary supplements .While many natural substances can extend the lifespan of nematodes, they act by regulating a small set of cellular pathways . One of the main cellular pathways that control C. elegans lifespan is the insulin pathway induced by food intake. This pathway consists of DAF-2 , several conserved protein kinases, and DAF-16 . In nematodes, insulin-like peptides bind to DAF-2 and induce intracellular signaling that leads to phosphorylation of DAF-16, thereby sequestering the transcription factor in the cytoplasm; in the absence of insulin-like peptides and DAF-2 signaling, as occurs when food is scarce, DAF-16 migrates into the nucleus where it induces expression of several genes including heat-shock proteins and antioxidant enzymes like superoxide dismutase and catalase , as well as autophagy-related proteins.

Another pathway activated by food intake involves the target of rapamycin , which is activated by nutrients and amino acids . Inhibition of TOR activates skinhead 1 , the homolog of nuclear factor erythroid-2- related factor proteins, and defective pharyngeal development protein 4 , the homolog of human FOXA proteins, leading to expression of detoxifying enzymes and activation of autophagy, respectively. TOR inhibition also activates autophagy by inducing basic helix-loop-helix protein 30 , the homolog of HLH transcription factor EB. In addition, the nicotinamide adenine dinucleotide -dependent protein deacetylase Sir-2.1, the homolog of human sirtuin-1, induces anti-aging effects at least in part by stimulating DAF-16 activity . Phytochemicals were previously believed to produce beneficial effects on health and longevity mainly by acting as antioxidants that scavenge reactive oxygen species .However, several lines of evidence indicate that these molecules may act in other ways, notably by inducing stress resistance and anti-aging pathways. Accordingly, the antioxidant properties of phytochemicals in vitro do not correlate with anti-aging effects in C. elegans. Moreover, some phytochemicals can, instead, extend C. elegans lifespan by inducing ROS formation, which in turn leads to expression of SKN-1 and antioxidant enzymes that protect from oxidative stress by inactivating ROS. For example, theophylline, a methylxanthine compound found in cocoa, chocolate, tea and guarana, slightly increases ROS levels in C. elegans, which prolongs lifespan and increases resistance to the ROS-producer juglone. Plant molecules that induce ROS formation may activate c-Jun N-terminal kinase 1 and DAF-16 . Other phytochemicals activate SKN-1 and lead to reduction of ROS in a similar manner .

While several plant-derived compounds extend lifespan in nematodes, conflicting results have been obtained in some cases, possibly due to differences in study design or experimental conditions. For instance, the Caenorhabditis Intervention Testing Program, which aims to identify antiaging compounds that prolong lifespan in genetically diverse cohorts of C. elegans, reported that aspirin does not extend lifespan, contradicting the results of previous studies.It has been proposed that many molecules derived from plants and fungi induce stress resistance and defense mechanisms via hormesis, i.e., which posits that cellular stress that is detrimental at high intensity can produce health benefits at low intensity. By activating autophagy, mitochondrial biogenesis and expression of antioxidant and detoxifying enzymes, plant and fungal products reduce cellular damage and improve cellular functions, thus reducing aging and extending longevity. This mechanism is consistent with the concept that, under conditions of stress such as CR, the organism allocates more energy for resistance and survival, instead of growth and reproduction. The hormetic dose-dependence is observed in several studies listed in Table 1. For example, treatment of C. elegans with an extract of Siberian ginseng extends mean lifespan by 5% at low dose and by 16% at intermediate dose , whereas the same extract reduces mean lifespan by 23% at high dose. Similar hormetic doseresponses involving lifespan extension at low doses and lifespan shortening at high doses were obtained for plant extracts of Rhodiola rosea and mistletoe, and for the tea polyphenol epigallocatechin gallate, to name a few. However, this dose dependence has been largely overlooked in many studies, while in other cases, a relatively narrow range of concentrations tested may have prevented the observation of hormetic dose-responses. Another observation suggesting that plant and fungal compounds extend lifespan via hormesis is the fact that stress resistance pathways are activated in the treated worms. Thus, many plant and fungal compounds that include 4,4’-dimethoxychalcone, glucosamine, nordihydroguaiaretic acid , resveratrol and spermidine extend the lifespan of C. elegans by activating autophagy , which in itself is a typical cellular response to stress. We also observed that polysaccharides isolated from the medicinal fungus G. lucidum extend the lifespan of C. elegans by inducing autophagy . In addition, several plant and fungal products increase the levels of HSPs and antioxidant and detoxifying enzymes , reflecting a cellular response that aims to maintain homeostasis in response to stress. Plant and fungal compounds can also induce mitochondrial biogenesis via a process referred to as “mitohormesis”.

High levels of ROS usually induce cellular damage, but as mentioned above some phytochemicals can induce the formation of low levels of ROS which in turn induce stress resistance mechanisms. In this case, cells respond by forming new mitochondria which in turn may improve cellular function and longevity. Examples of natural compounds that act this way in nematodes include EGCG and glucosamine . Of note, excess intake of antioxidants such as vitamins C and E may reduce the health benefits of anti-aging interventions like exercise in humans by preventing mitohormesis. In the studies consulted, plant and fungal extracts and molecules extend mean or median lifespan of nematodes by an average of 4 to 63% . These lifespan extensions are consistent with the hormetic effects observed in a large number of studies reporting the responses of microbes, plants and animals to various forms of biological stress, in which maximum effects of 20–90% above control were reported. While hormetic responses may be relatively modest in magnitude, they are nevertheless highly significant in view of their overall impact on health and longevity. Of note, plastic flower buckets wholesale only some plant or fungal substances increase maximum lifespan, producing increases ranging from 7 to 68% . While a description of the effects on maximum lifespan may have been omitted in some studies, this observation nonetheless suggests that the treatments may reduce the number of deaths in adult worms at some point in time but fail to extend the lifespan of old worms. Given that hormetic effects have been attributed to an overcompensation of homeostasis-regulating mechanisms and may thus rely on the capacity to maintain homeostasis, the absence of effects on maximum lifespan in some studies may indicate that very old individuals are unable to maintain homeostasis in response to biological stress, possibly due to a loss of resilience. Consistent with this possibility, feeding C. elegans with metformin late in life produces toxic effects and reduces lifespan by exacerbating age related mitochondrial dysfunction, unlike the lifespan enhancing effects of metformin seen in younger worms. Similarly, the lifespan-extension effects of EGCG decline with age. This indicates that CR mimetics—and possibly other anti-aging interventions that work through hormesis—may be ineffective and even detrimental in very old individuals.While studies in C. elegans have focused on extension of lifespan, many reports showed that natural substances that extend lifespan also produce beneficial effects on health span. For instance, plant-derived polyphenols such as chlorogenic acid, which is found in vegetables and coffee, improve insulin sensitivity and mobility in the treated worms. Similarly, carnosic acid, a diterpene compound isolated from rosemary , improves mobility and aging-related pigmentation and neurodegeneration in nematodes. These observations are consistent with the view that interventions that prolong lifespan may also improve physiological functions and reduce development of chronic disease. Recent studies suggest that some of the beneficial effects on health and longevity in nematodes may take place via modulation of the gut microbiota. A key study showed that Escherichia coli mutants deficient in some biochemical components can extend nematode lifespan. This study reported that production of the polysaccharide colanic acid by gut bacteria can extend lifespan and reduce age-related pathologies by inducing the unfolded protein response in the host. Similarly, metformin can extend lifespan and regulate host lipid metabolism via production of the metabolite agmatine by the gut microbiota. Other studies showed that a strain of the probiotic Lactobacillus rhamnosus or Weissella bacteria activated the DAF-16 pathway and extended C. elegans lifespan compared to feeding with E. coli . However, these results may also be partially explained by the observation that E. coli becomes pathogenic for old worms and feeding with less pathogenic bacteria may therefore extend nematode lifespan. Given that major differences exist between gut microbiota composition in C. elegans and humans—including the fact that the gut microbiota in nematodes studied in vitro usually consists of a single bacterial species provided as food— further studies are needed to assess the relevance of these observations in humans.Recognition of the potential importance of homologous recombination in the evolution of bacteria has been steadily growing since the work of Smith et al. . Recombination of homologous donor DNA into the bacterial chromosome appears to be ubiquitous, although the relative importance of recombination versus mutation in driving evolutionary change varies widely among species . Homologous recombination typically involves relatively small pieces of DNA , which suggests entry of donor DNA into the bacterial cell via transformation. However, not all species with significant levels of recombination, such as Escherichia coli, are typically competent for transformation , and it is also possible that large pieces of DNA entering the cell via conjugation may be cleaved into smaller pieces before recombination occurs. Regardless of the processes that make donor DNA available, it is clear that homologous recombination in bacteria is an important mechanism of genetic exchange. Like sex in eukaryotes, recombination blends genetic variation and as such acts as a cohesive process that can inhibit the subdivision of taxa , but when the donor DNA comes from a genetically differentiated population, recombination can dramatically increase genetic diversity. However, the critical issue raised by Smith et al. of why the relative rate of recombination is so variable across taxa remains unresolved. This issue is unlikely to be resolved until we understand more about the benefits of homologous recombination.

Similarly, some robust annual populations were able to produce enough flowers over the extended growth season in this mesic habitat to outperform the focal population. Conversely, fast-cycling annuals appeared developmentally unable to exploit the longer growth season in this habitat, flowering earlier at a small size and producing few flowers . The relatively low performance of the montane perennial ecotype could reflect inbreeding depression and/or a bet-hedging strategy that prioritizes adult persistence through below-ground rhizomes at the expense of reproductive output in any given year . Together, the relative performance of both immigrants and hybrids was quadratic with phenotypic divergence, suggesting that ecologically intermediate genotypes enjoy a fitness advantage whereas increasing phenotypic divergence results in immigrant inviability or, potentially, reduced hybrid performance. This pattern may be common during the early stages of ecological divergence due interactions between inbreeding depression and divergent adaptation . I found strong support for this hypothesis by manipulating the inbreeding history prior to hybridization, suggesting that, in many systems, selection against immigrants and hybrids may not be the earliest or strongest barriers to evolve. Indeed, procona system several studies have failed to find selection against immigrants or hybrids even when other ecological barriers are present.

Several lines of evidence suggest that the traits underlying reproductive isolation in this study are the result of divergent selection between annual and perennial habitats. The trade-off between rapid flowering and vegetative growth is a major axis of phenotypic divergence in this species complex that is determined by multiple pleiotropic QTL . Early flowering is under strong selection in fast-drying annual habitats, whereas later flowering and/or greater vegetative growth are favored in coastal and montane perennial habitats . Correspondingly, flowering time isolation in immigrant populations was greater for annuals than inland perennials, whereas immigrant and hybrid fitness was greatest for inland perennials that invest in vegetative growth. Reduced viable seed set could be due to pollen-pistil incompatibilities preventing fertilization or early-acting genetic incompatibilities in developing hybrid seeds. Although the traits driving these barriers are as yet unknown, the relationship between crossing barrier strength and phenotypic divergence suggests a role for natural selection. Crossing barriers with the focal population were stronger in inland perennial populations than annual populations, and this pattern could reflect differences in life history strategy. Fecundity selection is strong in annual populations but weaker in perennial populations, where other components of fitness including survival and growth also shape the pattern of selection . Relaxed fecundity selection in perennial populations could allow more rapid genetic divergence in loci related to pollen-pistil interactions or seed development, potentially increasing the likelihood of incompatibilities.

Future research should identify the mechanisms underlying crossing barriers to test this hypothesis.What determines whether partially isolated taxa will evolve into good species, remain partially isolated ecotypes, or collapse into a single population?Parallel ecological contrasts have yielded variable progress toward genetic isolation among White Sands lizards , lake-stream stickleback , insect host-races , and mimetic butterflies . Several hypotheses have been developed to explain variation in progress toward speciation, including the strength and consistency of selection, the number of traits or loci mediating adaptation or isolation, and opportunities for gene flow and reinforcement . I found no evidence that reproductive isolation was related to geographic distance, a proxy for opportunities for gene flow. Alternatively, individual barriers and total reproductive isolation with a focal montane perennial population were correlated with phenotypic divergence. Yet, the strength of total isolation was still incomplete and dependent on environmental variation between years as well as the history of inbreeding. Reproductive isolation with a montane perennial population is weaker than reproductive isolation between annual and coastal perennial ecotypes in this species . In annual populations, late-flowering coastal perennial genotypes face nearly complete immigrant inviability due to their inability to reproduce prior to the onset of drought. In coastal habitats, annual genotypes have reduced fitness due to salt spray and flower earlier than the native coastal perennial genotypes, while F1 hybrids exhibit strong heterosis. Together, reproductive isolation in these habitats ranges from 0.93 – 1.00 , exceeding estimates from this study which ranged from 0.60 – 0.76 for annual populations including hybrid fitness. The differences in reproductive isolation among these life history ecotypes suggests that strong viability selection early in the life-cycle, due to drought or salt spray, is an important factor in the rapid evolution of strong reproductive isolation.

Drought avoidance traits are highly correlated among populations of M. guttatus , providing support for the view that strong selection on few traits, such as rapid development or salt tolerance, promotes speciation . However, quantitative genetic studies have demonstrated a polygenic basis for both flowering time and salt tolerance in this species , such that selection on individual loci may be weaker. Negative pleiotropy between early flowering and vegetative rosette production could generate fitness trade-offs between annual and perennial habitats , whereas Lowry et al. found no fitness costs for salt tolerance QTL in an annual habitat. Thus, although conceptually useful, distinguishing between the stronger selection and multifarious selection hypotheses may be difficult in practice.The broader community of microbes within a host, the microbiome, can determine the health status of an individual. Many microbes provide beneficial functions for the host including metabolism and immunity. In honey bees, certain Lactobacillus strains offered protection against a microsporidian and bacterial pathogen. Similarly, in bumble bees, increased microbiome diversity was linked to reduced infection by the trypanosomatid parasite Crithidia. In Osmia ribofloris, the pollen provision microbiome is crucial for larval development. Therefore, it is important to characterize and understand the microbiome to understand bee health. Our current knowledge on the microbiome of bees is predominantly based on honey bees , and to a lesser degree bumble bees. Both of these are highly social and closely related members of the corbiculate apid bees, and as such they share a very similar core microbiome. Outside of these genera, the bee microbiomes sequenced so far do not conform to the Apis and Bombus models. Even within the corbiculates, the stingless bees and the orchid bees lack some of the most common symbionts of Apis and Bombus, although several related symbionts are shared amongst the corbiculates. Looking more broadly, bacteria thatwere previously classified as Lactobacillus but have been recently split into the genera Apilactobacillus, Bombilactobacillus and Lactobacillus sensu strictu are some of the few symbionts common to multiple bee taxa including Apis, Bombus, the small carpenter bee Ceratina, megachilid and halictid bees. Microbe acquisition in Apis and Bombus occurs within the hive, facilitated by nestmate interactions or transfer from feces. While honey and bumble bees live in large groups, this level of sociality is rare among bees, the vast majority of bee species being solitary.

Indeed, in the other bee species studied so far, much of their microbiota appears to be gained from the environment rather than through social transmission. Therefore, differences in environmental and pollen-associated bacteria may have larger impacts on wild bee development than for the highly social corbiculate bee species. Microbial acquisition from the environment may be influenced by the diet of the bee. As for bees, flowers harbor a variety of microbes, which can potentially be passed to foraging bees. Crithidia can be transmitted between foraging Bombus at flowers and communities of pollinators have been found to share microbes. For bees that use foliage to line their nests, procona valencia buckets both flower and foliar source affect their pollen provision microbiome. However, there are also many more complex factors to consider such as flower morphology, volatiles and even the secondary compounds produced by the microbes themselves, that can alter floral bacterial communities and transmission to pollinators. Therefore, diet may be an important factor to consider when looking at the wild bee microbiome, which is thought to be largely environmentally sourced. To conserve wild bees, we need to understand their health, and their associated microbial symbionts. It seems likely that the microbes present in the environment, and therefore those gained environmentally by bees, will vary geographically with changes in climate, interacting insect species and floral communities. Ceratina calcarata Robertson, 1900 is a small carpenter bee species that is a widespread and prominent pollinator across eastern North America. This species nests in the dead stems of various plants, commonly raspberry and sumac. The plants it nests in also produce flowers, potentially biasing pollen collection and thereby microbial acquisition. This bee constructs separate brood cells within the stem nest, each provisioned with a single pollen ball on which an egg is laid . This brood provision is the only source of food given to the offspring until it reaches maturity. Study of these brood provisions from nests at the northern extent of its range found they contain multiple pollen species and a diversity of microbes dominated by Lactobacillus, Wolbachia, Acinetobacter and Sodalis. However, C. calcarata is found across a broad geographic range in eastern North America and acquires at least part of its microbiome from the environment, therefore its microbiome may vary geographically with corresponding changes in climate and floral landscape. The aim of this project was to investigate whether the microbiome of C. calcarata varies geographically by sequencing brood provisions spanning this species’ range across the eastern United States. Specifically, we asked whether pollen or bacterial species vary in composition or diversity among sites and if there are identifiable plant/microbe associations. We also asked whether foraging was biased by the proximity of nest plant flowers.The floral resources utilized by C. calcarata differed between regions, brood provisions being dominated by different pollen genera in each state, showing this generalist bee’s local adaptation to regional floral communities . Foraging preference was not biased towards flowers present on the host nest plant, indicating that spatial assortment of floral resources alone does not determine foraging preferences. Despite changes in floral resources, the same core microbes dominated brood provisions across all states, although the relative abundance of these groups did vary between region . Our overall network analyses identified some correlations in plant and bacterial occurrences, however the broad changes in floral diet between states did not correspond to large changes in the bacterial community, suggesting that these floral–bacterial associations are transient or non-obligate . There were a number of core bacterial genera found across all sites but the relative abundance of these varied strongly . Comparison to McFrederick and Rehan’s study in New Hampshire suggests there may also be annual variation within sites. In 2016, Lactobacillus was the most common genus, while we recovered Sodalis and Wolbachia as the top two genera in the current study . Being obligate facultative endosymbionts in many insect species, the occurrence of Wolbachia and Sodalis is likely due to contamination from mites or other parasites, or transfer directly from the mother’s crop rather than through any specific floral sources. A major limitation of amplicon sequencing studies is that they can only determine the presence or absence of an organism’s DNA, not whether that organism is metabolically active, and this holds true for all bacteria recovered in our samples. This aside, it is interesting that Wolbachia contamination is so prevalent, and future microscopic examination of pollen material for mite infestation and tests of possible vertical transmission via pollen are needed. Lactobacillus was only present in 2.2% of reads in the New Hampshire samples for this study. Within Georgia, the abundance of bacterial ESVs differed between nests in Rubus and Rhus but significant differences disappeared when the phylogenetic similarity of bacteria was considered. This suggests there could be some differences in the abundance of microbial species or strains between nesting substrates but overall the taxonomic distribution of bacteria in the brood provisions is similar. Nesting substrate, therefore, has a smaller or negligible effect on bacterial abundance compared to differences among states. Ceratina calcarata foraged from a slightly greater phylogenetic richness of floral genera in New Hampshire than in Georgia. The phylogenetic richness of floral genera in Missouri did not significantly differ from either Georgia or New Hampshire, perhaps because of its mid-lying geographic position and climate. As expected, our reanalysis of the New Hampshire data with 99% ESV matching recovered fewer genera than in McFrederick and Rehan, who found 110 genera compared to this study with 65. The genera not recovered in our reanalysis were all present in less than 1% of reads in the original study. We identified the same five genera as being the most abundant , these genera accounting for 92% of the reads .

In addition to contributing to a better understanding of how change in landscape use, particularly urbanization, affects pollination-plant interactions, the study illustrates the importance of use of neighboring lands for pollination services.Our study system was located around Brentwood, in east Contra Costa County, California, where natural, agricultural, and urban areas intersect with each other within a 20620 km region . A county water district , regional park district , and California state park all fall within the region, leaving large areas of land protected from development. This protected land consists mainly of grasslands and oak woodlands, some portions of which are managed for grazing. East Contra Costa County has had a farming community presence since the late 19th century. The agricultural areas of Brentwood, Knightsen, and Byron mostly consist of orchards , corn, alfalfa, and tomatoes . A housing boom in the 1990s led to massive residential growth in the area. The city of Brentwood has grown from less than 2500 people in the 1970s to over 50,000 today , blueberry in pot and nearby Antioch has now over 100,000 residents .Bee Visitation We observed visits by all bee species to yellow starthistle at all sites 3 times for a 30 min period for a total of 90 min of total observation time per site within the same 2 wk period in August 2011. AM was defined as being between the hours of 9:30–11:30, Mid-Day as between 11:30–13:30, and PM as between 13:30–15:30. All observations were conducted by the same individual to avoid sampling biases. Also recorded at each observation period were approximate number of blooms, and wind and temperature simultaneously .

Bees were not netted for later identification as we did not want to interfere with visitation to starthistle during this study. Instead, we used a modified protocol of citizen scientist observation surveys with 15 expected bee morphotypes that correspond to 30 possible genera known to occur in the region . The observer slowly walked through the yellow starthistle patch, and upon reaching patch edge, returned on a path at least 3 m away from the previous, and recorded the morphotype classification of all bee visitors within 1.5 m on either side of the transect. Seed Set Yellow starthistle has composite flowers, which are aggregations of anywhere from 20–80 florets. At each site, 12 yellow star thistle buds were randomly selected from different plants and covered with a mesh bag. Yellow starthistle blooming cycles have been described in detail in other publications. We selected buds at stage BU-4, when buds had no yellow petals exposed, but had well-developed straw-colored spines. When in full flowering, 10 bags were opened for a 4 hour period from 10 am to 2 pm, while 2 were kept closed as controls to verify that self-pollination was not occurring. At the opening and re-closing of the bags, the number of florets that had their stigmas extended were counted. Later, when flowers were fully mature , seed heads were collected, and later dissected in the lab. Viable and non-viable seeds in yellow starthistle seed heads are easily distinguishable based on color and shape. Because yellow starthistle requires pollination to produce viable seeds , non-viable seeds represent pollen limitation occurring during the 4-hour period that the flowers were exposed to pollinators.

All seeds were counted to compare ratios of viable to non-viable seeds. Any seed predation was noted, and when possible, the seed predator was identified. Analyses All analyses were done in R 2.15.1 . Because each site had an AM, Mid-Day, and PM observation event, there were a total of 36 observation events, each with unique wind and temperature recordings, and visit observations of the 15 bee morphotypes. From these, we calculated the total number of bee visitors, total number of bee morphotypes, Shannon diversity of morphotypes, and morphotype evenness. The spatial autocorrelation of all bee visitor response variables was assessed by Mantel tests in R package ade4, using the average values for each time of day at each site. Spatial autocorrelation was not detected . To test for the effect of land use type on each of the response variables we used a generalized linear mixed model using the R package lme4. We designated land use type, bloom category of flowering patch, observation time period, wind, and temperature as fixed effects and site as a random effect. Natural land use and AM observation time period were the model baselines for the categorical variables of land use type and observation time. Shannon diversity and evenness were fit with Gaussian distributions while all other variables were fit with Poisson distributions. In comparing the ratios of viable seeds to total seeds vs. the ratio of viable seeds to counted stigmas, we found that there was a strong correlation between these metrics. To look at the effect of land use type on seed-set, we therefore decided to utilize the ratio of viable seeds to total seeds in each seed head that did not experience seed predation, because of error in counting the number of stigmas .

We then used a generalized linear mixed model fit with a Binomial distribution, with land use type as a fixed effect and site as a random effect. Finally, we tested for an effect of floral visitor observations on yellow starthistle seed set at each site. We averaged the number of visits from each morphotype across temporal observation events at the same site. Morphotypes that averaged at least one visit per 30 minute observation window were included as fixed effects in alinear mixed model fit with a binomial distribution, with site as a random effect and the ratio of viable to total seeds as the response variable. We also modeled the effects of total bee visitation, morphotype richness, and morphotype diversity on seed set ratios. Our results show that rates of bee visitation and seed set vary among urban, agricultural, and natural landscapes, demonstrating the importance of land use in the dynamics of plant-pollinator interactions. We suggest that these effects are at least in part explained by floral availability, a vital bee resource, which can be highly variable among different land use types. For example, in August there are few plants in flower besides yellow starthistle in the natural areas of Contra Costa County, California, whereas in urban and agricultural areas there are many exotic plants and supplementary inputs available . From pantrapping of bee specimens in the region , we know that total bee abundance is highest in the spring in natural areas. However, towards the end of the summer when yellow starthistle is in flower, there is little difference in collected bee abundance between human-altered landscapes and natural areas, and human-altered areas may even exhibit overall higher bee abundance. Our results of bee visitation to yellow starthistle support this pattern. Agricultural areas have large populations of managed honey bee colonies, so one would predict visitation to yellow starthistle by honey bees to be positively associated with surrounding agricultural land use. By contrast for native bees , the highest rates of visitation to yellow starthistle were in sites with more surrounding urban land use. Urban gardens have many exotic plants, often selected for aesthetic purposes, many of which are in flower later in the season than most California native plants. In addition, many of the plants in urban areas both directly and indirectly receive supplementary resources, particularly water, that further extend their flowering time. Even though agricultural areas also have supplementary resources, the main crop in flower in East Contra Costa County later in the season is maize, plastic planter wholesale which is wind pollinated. There may be multiple impacts of exotic plants in urban areas. By filling the phenological flowering gap noted above, they may help attract even larger populations of bees into the urban landscape. In addition, bees in urban sites may be behaviorally more likely to visit non-native plants due to the increased encounters they have with novel plants. In agricultural and natural landscapes, a positive correlation between pollinator visitation and seed set is typical. Surprisingly in our system, in human-altered landscapes, higher total observed bee visitation did not result in higher proportions of seed set, as would be expected. In fact, urban areas, despite receiving the highest rates of native bee visitation, exhibited the lowest rates of seed set.

Conversely, natural areas, which received the lowest amount of total bee visitation, had the highest rates of seed set. We suggest 2 possible explanations for this discrepancy between pollinator visitation and rates of seed set: 1) pollinator efficiency; and/or 2) the composition of the local flowering community. Depending on the plant, certain pollinator species are much more effective than others. For example, Osmia, Habropoda, and Apis, have been found to produce varying amounts of seed set as a result of a single visit to blueberry, but these results vary slightly depending on the blueberry variety. In the case of yellow starthistle, it is likely that the most frequent visitors are perhaps not the most efficient. When we directly compared average seed set at each site against visitation rates, we found a significant positive association with the medium hairy leg bees. The medium hairy leg bee morphotype includes those species which fall in both the Tribes Emphorini and Eucerini. Emphorini are known to largely be oligolectic , meaning they specialize on certain plant groups, which theory suggests would make them more efficient pollinators than generalists. The medium hairy leg bee morphotype was not significantly associated with any of the land use typesIt was also the only group that was observed most frequently during morning sampling, perhaps reflecting a difference in when yellow starthistle is most receptive to pollination. Despite the overwhelming abundance of honey bees in agriculture areas, we did not observe higher seed set in those regions, consistent with the observation that honey bees can be poorer pollinators than other species.It is also important to note that this study used a morphotype classification, and there may be multiple species that fit within the same morphotype that provide varying degrees of pollination services. It is possible there are rare, but highly efficient, pollinators that were rarely observed during the sampling period, or were lumped together with a more frequently observed morphotype. An alternative explanation for the lack of an association between floral visitation and seed set is that higher plant diversity in urban and agricultural areas may decrease pollinator efficiency. Previous research has shown that invasive alien plants can have a negative effect on native plant communities by acting as attractors for pollinators, or decreasing pollinator efficiency by providing a wider range of resources for pollinators to visit, with the consequence that visitors transfer pollen from non con-specifics, potentially clogging stigmas and reducing pollination success. In this case, our target plant, yellow starthistle is indeed considered an invasive alien plant, but the hypothesis of it being in a novel diverse community could lead to a similar effect on the frequency and quality of pollination services that it receives. In sites where there are many other potential plants to visit and accompanying decreased floral fidelity leading to diverse pollen loads, one predicts decreased pollinator efficiency. Abundant sources of exotic plant pollen could occur in areas where there is a greater diversity of nearby plants for pollinators to visit. This explanation might account for the observation that shield-tipped small dark bees were negatively correlated with seed set. We selected yellow starthistle as the target plant for this study because of its ubiquitous distribution, reliance on pollination, and its attraction for a wide set of visitors; it is also a highly invasive and undesirable plant. Previous research on yellow starthistle has found that its invasion can be facilitated other non-native pollinator species such as the honey bee, Apis mellifera, and the starthistle bee, Megachile apicalis, which is included in the medium striped hairy belly bee morphotype. However, the abundance of bees in both of these 2 morphotypes were most closely associated with agricultural areas, which did not have the highest rates of seed set as would be predicted by visitation alone. Our results indicate clearly that bee visitation in human-altered landscapes can be higher than that in comparable natural areas, especially towards the end of the flowering season when there are few resources available in natural landscapes.

As the occurrence of drought proliferates globally due to increased aridity resulting from anthropogenic climate change , drought-induced pollen limitation as mediated by pollinators may become a common and pressing concern in ecosystems worldwide. The degree of pollen limitation partly depends on how pollinators move, and thus transfer pollen, amongst flowers within and between plants. For example, increased pollinator visitation within the same plant could increase instances of self-pollination, which may heighten inhibitory effects of drought on reproduction. But if pollinators increase rates of outcrossing or preferentially forage on plants producing higher quality pollen, then pollen limitation resulting from reduced water availability may be alleviated. Chapter 1, in part, is currently being prepared for submission for publication of the material. Gambel, Jess; Holway, David A. The dissertation author was the primary investigator and author of this material.Drought represents an increasingly prevalent abiotic stressor in terrestrial ecosystems . For plants, water stress decreases plant turgor, leaf water potential, and stomatal conductance, leading to reduced photosynthetic activity and slower cell growth . Accordingly, effects of drought can lead to diminished reproductive investment: decreased flower production , reduced flower size , reduced pollen production and viability , diminished nectar volume and sugar content , collection pot modification of floral coloration , and altered emission or composition of floral volatile organic compounds .

Changes in floral traits caused by drought may subsequently influence pollinator behavior and, in turn, plant reproductive success . The roles of different pollinators in mediating how plants respond to drought will be influenced by their behaviors. Generalist pollinators, for example, visit a diversity of plants, sometimes from many different families, for nectar and pollen, whereas specialists obtain pollen and nectar from a limited number of related floral hosts and often depend on resources from specific host plants to reproduce . Bees provide excellent examples of this continuum. Polylectic bees collect pollen from many unrelated plants, but specialist bees are restricted to pollen collection from few related species . Accordingly, specialists may be expected to exhibit higher floral constancy  than generalists, which they do, on average, and this behavior contributes to the effectiveness of specialists as pollinators . However, exceptions also exist . As drought stress affects a suite of floral traits, it often results in reduced visitation by pollinators . Specialist pollinators that depend on pollen from a species or genus of plant will be unable to switch resources as a result of plant-to-plant variation in floral resource quality. Generalists, in contrast, may exhibit selectivity for high-quality floral resources given that they have a broader set of resources available to them. While generalist pollinators are considered more resilient to habitat and climatic disturbance compared to specialists , few studies have compared how specialist and generalist pollinators respond to drought conditions.

Minckley et al. , for example, found that bees specializing on creosote bush, which does not flower in drought, failed to emerge and visit creosote during a drought year; however, specialists of mesquite, which flowers independently of rainfall because of its ability to use tap roots to access groundwater, were able to remain active. Conversely, Mayer and Kuhlmann discovered that during a drought year, specialist and generalist bees of Rediviva emerged on time with the normal flowering season despite bloom being postponed by five weeks; this asynchrony resulted in the loss of pollen collection by bees.Here, we use field experiments to examine these relationships for cultivated squash pollinated by honey bees , which are generalists, and squash bees pruinosa, E. strenua, which specialize on Cucurbita to such an extant that they require pollen from these plants to reproduce. The squash system is highly appropriate for this type of investigation. Given that Cucurbita do not self-pollinate , they need insects to pollinate their flowers to produce fruit and seeds. Moreover, squash plants have separate male and female flowers that are large and short-lived ; these attributes facilitate examination of pollinator behavior and responses by plants. We test three predictions concerning how specialists and generalists respond to plants experiencing a gradient of drought stress and how these changes in foraging behavior may affect plant reproduction. First, generalists should exhibit selectivity while specialists should be indiscriminate in terms of displaying preferences in the quality of floral resources. Second, higher selectivity by generalists should translate into increased transfer and deposition of pollen from male flowers of non-drought stressed plants onto floral stigmas of female flowers of non-drought stressed plants . Third, increased deposition of pollen from non-drought stressed plants could increase fruit set and seed set if pollen from drought stressed plants is low quality.

In seasonally dry environments, water stress likely affects floral resource quality on a regular basis, and pollinator behavior may play an important role with respect to how those resources move amongst plant species. This study represents a novel investigation into how the effects of drought on plant reproductive success hinges on the behavior of specialist and generalist pollinators.We used a drip-line system to irrigate plants every morning with the daily amount of irrigation held constant until plants were three weeks old. After that time, when plants were mature enough to survive drought stress, we divided them into two groups. Plants either received 2.2 L water/plant/day or 0.35 L water/plant/day . Plants in the two irrigation groups were spatially interspersed with respect to one another. We used a FieldScout TDR 100© soil moisture meter to take 2 – 4 replicate measurements of volumetric water content in the soil at 20 cm below each plant one hour after watering, 2-3 times per week for the duration of the season . Volumetric water content decreased by an average of 10% for plants in the low-irrigation group compared to the high irrigation group . Mean volumetric water content, however, varied from 38 – 51% to 24 – 48% . Given that soil moisture levels exhibited substantial variation within each irrigation group, we considered soil moisture as a continuous variable in most statistical analyses but use treatment group designations in the organization of the experiment. Within the high-irrigation and low-irrigation groups, plants were randomly assigned to either a bee-pollination group or a hand-pollination group . Plants in each pollination group were spatially interspersed. Hand pollination was used to control the source of pollen and to examine the subsequent effects in terms of plant reproduction. Once squash plants began to flower in mid-July, flowers on hand-pollinated plants were bagged prior to opening to prevent bee visitation . For bee-pollinated plants, we measured traits on a subset of female and male flowers that we bagged before they opened to prevent bee visitation . On the morning that bagged flowers opened, we detached them from the plants while still bagged and then carefully removed each flower from its bag. On each flower, we measured corolla width, nectar volume, nectar concentration, pollen mass , and pollen viability . Appendix 2.1 describes methods used to measure each floral trait. Throughout the season, we kept daily tallies of the number of male and female flowers open on each plant to assess how soil moisture variation affected plant-level, seasonal flower production. For bee pollinated plants we video-recorded flowers to quantify pollinator behavior and frequency of visitation, 10 plastic plant pots and used fluorescent pigments to investigate how bees transport pollen among plants grown under different levels of soil moisture. We recorded bee visitation on high-irrigation and low-irrigation plants concurrently; therefore, each day bees could move freely between plants in each irrigation group.

Videos of male flowers and female flowers were always recorded between 0700 – 0900. For every video, we set the video camera close enough to each flower to fill the frame of the video but far enough away such that bee visitation did not seem to be affected. For each video of a female flower, we counted the number of bee visits per unit time, and for each visit measured the time that each focal bee spent in contact with the stigma and drank nectar. For each video of a male flower, we counted the number of bee visits per unit time, and for each visit measured the time that each focal bee contacted the anthers, collected pollen, and drank nectar. We also conducted plot-level surveys of bee visitation to all open flowers each day . We used powdered DayGlo© fluorescent pigments to study patterns of pollen movement by bees . We used flat toothpicks to apply pigments to the anthers of all open male flowers prior to bee access to flowers . Male flowers in the low-irrigation group received one pigment color, whereas male flowers in the high-irrigation group received the other pigment color. Color assignments were switched daily. On the stigmas of bee-pollinated female flowers, pigment particle counts were positively correlated with pollen counts . Therefore, the number of pigment particles can serve as a proxy for the amount of pollen moved by bees from the anthers of male flowers to the stigmas of female flowers and also reveal patterns of pollen movement among plants in the two irrigation groups. We measured pigment deposition on the stigmas of 56 bee-pollinated plants. For plants with multiple stigma samples , we used mean values as data points. To hand-pollinate female flowers, we first applied fluorescent pigments to two male flowers as described in the previous paragraph and then removed pigment and pollen from the anthers of these flowers. We combined the pollen-pigment mixture from the two flowers in a petri dish and used a cotton swab to generously apply this mixture to the entire stigma of each female flower . After hand-pollination, we rebagged flowers with breathable mesh bags to exclude pollinators while simultaneously permitting flowers to experience similar conditions as those experienced by flowers open to bees . See Appendix 2.2 for additional information on pollen and pigment deposition on hand-pollinated stigmas. We allowed pollen to germinate on bee and hand-pollinated stigmas for 24 h before collecting stigmas from female flowers setting fruit. This amount of time allowed for pollen grains to fertilize ovules . We stored refrigerated stigmas in 100% ethanol , and later used a dissecting microscope at 40x magnification to count the number of different colored pigment particles deposited on the stigmas . We then dyed the stigmas with basic fuchsin solution and used a dissecting microscope at 50x magnification to count the number of deposited pollen grains . We also counted stained grains present in the ethanol solution to obtain an estimate of the total pollen deposited on the stigma. We estimated pollen deposition on 48 bee-pollinated plants; for plants with multiple stigma samples, we used mean values as data points. Fifty days after pollination , we harvested mature fruits from 47 bee-pollinated plants and 19 hand-pollinated plants. Seeds were removed from fruits in the lab, and then dried, counted, and weighed. We used total seed weight per fruit to estimate seed set. For plants with multiple fruits, we used mean values as data points. We used R version 3.6.1 for all data analysis and used the package ggplot2 to prepare figures . For all general linear models, we inspected q-q plots to test for normality, used Bartlett tests to assess homogeneity of variances, and tested the residuals of each model with the Shapiro-Wilk test for normality. We used simple linear regressions to assess how soil moisture affected the floral traits listed in Table 2.1. For plants in which more than one male or female flower was measured, we used mean values as data points. For the analyses of floral traits, the following response variables were right-skewed and thuslog10 transformed to improve normality of the residuals prior to analysis: male flowers produced, female flowers produced, male flower size, and nectar volume in male flowers. The proportion of viable pollen was left-skewed and thus square transformed to improve normality. To examine how bee visitation and behavior changes with respect to plant soil moisture , we used separate general linear models for honey bees and squash bees with soil moisture and total flowers available in the plot as fixed factors. We added flower availability to the model because the number of flowers available to pollinators increased with plant soil moisture . For analyses of bee visitation to male flowers, see Appendix 2.2 for information on how variables were transformed to improve normality. For the analysis of visitation to female flowers, Eucera visitation rate was right-skewed and thus arcsine square-root transformed to improve normality of the residuals.

The influence of large corporations had an average score of 6.6. This theme emerged in all of the focus groups, though it was much more strongly held by some individuals. One participant said, “The huge conglomerates that are controlling agriculture really, really bother me,” and others named specific multinational food processors and chemical companies whose motives they distrusted. Some participants blamed these corporations for the low prices that farmers receive for their products and the loss of family farms. How far food travels was the lowest-ranked topic on the survey, with a score of 5.8. Focus group participants had various reasons for their interest in this topic, involving economic, food safety, or environmental concerns. Most focus group participants wanted to know the country of origin of their food. “I guess I’d like to know [where fruits and vegetables are from] because I’d like to know are we producing our food or are we actually reaching out into other countries?” said one participant. Some participants wanted to support the U.S. economy, while others went further and expressed interest in supporting their local economies. Another stated reason for wanting this information was concern about the safety of imported food, such as the presence of pesticides banned in the U.S. or contamination with microbial diseases. Finally, some participants wanted to know how much fossil fuel was consumed in transporting their food. Of 60 survey respondents who identified additional topics in a write-in section, 22% had reservations about genetically engineered food, best indoor plant pots and 15% wanted more information on pesticides.

Other interests identified by more than one respondent were freshness, where food was grown, and the fate of food waste.As a soil scientist with the Center for Agroecology and Sustainable Food Systems , Marc Los Huertos helps farmers on the Central Coast manage nitrogen levels to maximize harvests and minimize pollution. Los Huertos is also part of a growing global effort to address the problem of farm-generated nitrogen pollution. Just back from the Third International Nitrogen Conference in Nanjing, China, Los Huertos has a sobering message for farmers: “China is ramping up agricultural production, and strong international environmental regulations could be what saves U.S. farming from a formidable competitor,” said Los Huertos, who manages the Center’s research program on water quality monitoring in a number of Central Coast watersheds. “I saw hundreds of miles of greenhouses,” Los Huertos said of a three-week tour of the Chinese countryside that followed the Nanjing conference. “If they can figure out how to get their produce here fast enough, the Chinese could outcompete U.S. farmers in no time at all.” Convinced that U.S. farmers have a huge stake in regulations that would force global competitors to clean up their act, too, Los Huertos is eager to increase public understanding of agriculture-related nitrogen pollution. “My job is to prepare farmers for policies that might affect them, whether at the state, federal, or international level, so I went to China to get a sense of the international movement,” said Los Huertos.Nitrogen accumulation reduces biodiversity, acidifies soil and water, degrades coastal environments, reduces forest productivity, contributes to the greenhouse effect, and depletes the ozone.

“Reactive nitrogen is so high in the developed world that we’re polluting ourselves out of clean air, drinking water, and biodiversity,” he said. Although essential to life, nitrogen must be converted from a gas to a reactive form to be usable by most organisms, including plants. The accumulation of reactive nitrogen in the environment is largely a result of the conversion of enormous quantities of nitrogen into fertilizers that are used in the production of food and fiber. Reactive nitrogen is also a by-product of fossil fuel combustion for transportation and energy production. A significant portion of nitrogen in fertilizer is never taken up by plants and instead runs off, contributing to the “cascade” of atmospheric and aquatic nitrogen accumulating in many regions of the world—even as most of Africa and parts of South America and Asia suffer from a deficiency of reactive nitrogen in the soil. In Nanjing, about 800 conference participants approved the “Nanjing Declaration on Nitrogen Management,” which urges the United Nations Environment Program to promote understanding of the nitrogen cycle, assess consequences of its disturbance, provide policy advice and early-warning information, and promote international cooperation. With Center director Carol Shennan and researchers Claire Phillips and Alex Fields, Los Huertos monitors nitrogen in several important waterways along the Central Coast, including the Pajaro River and around the Elkhorn Slough, one of the largest remaining tidal wetlands in California. Nitrogen levels in Central Coast agricultural watersheds have steadily increased since the 1950s, when levels of <1 ppm were typical, according to state records compiled by Los Huertos. Today, Los Huertos regularly documents levels of 10 ppm in May and 20 ppm in the fall in the Pajaro River. Drinking water standards allow for a maximum of 10 ppm. Unlike some coastal areas where fertilizer runoff has wiped out marine life, Monterey Bay circulates the ocean water and flushes nutrients through the ecosystem. This mixing and upwelling make it difficult for scientists to assess how nitrogen runoff affects the bay, but it certainly has a role in the freshwater streams, according to Los Huertos. “We know we have excess nitrogen on the Central Coast, and farmers and the state and federal government are struggling with finding ways to control polluted runoff,” said Los Huertos.

In other coastal areas, runoff from nitrate-based fertilizers has had devastating consequences. In the Gulf of Mexico, a 5,000-square-mile area from the mouth of the Mississippi River almost to the Texas border is overrun with nitrates each summer, triggering an algae bloom that severely reduces oxygen levels until late September.As “alternative food movements” have gained momentum, they have helped transform institutions from the U.S. Department of Agriculture to the University of California, argues Allen. She notes that, “Universities across the country have sustainable agriculture programs, and the USDA has programs that were unheard of 20 years ago.” In her book, Allen examines the shortcomings of the current conventional agriculture system, and the ways that alternative agrifood movements are addressing problems such as environmental degradation and lack of food security. She analyzes the interactions of alternative movements with mainstream institutions such as the USDA and land grant agricultural research system, describing the way their research agendas and methods are beginning to change. She addresses the importance of building broad-based alliances for developing alternative agrifood systems, and some of the emerging connections between groups working for environmental change and those concerned with social issues. Allen also documents some of the problems with the current efforts to reform the conventional agricultural system. She points out the way that, in an effort to avoid controversy or upset the status quo, alternative ideals such as social justice may be watered down or slighted within traditional institutions such as academia or extension programs. Allen warns that some of the problems of the dominant agrifood system are being repeated within the movement toward a more environmentally sound and socially just system, and suggests ways to avoid such repetition. She also critiques the drive toward food-system localization as a strategy for the sustainable agrifood system movement, noting for instance the enormous differences in wealth and resources from one community to another. Allen is particularly concerned by what she sees as two major problems in the movement to develop a more sustainable agriculture and food system: the lack of a coherent vision, and the paucity of attention being paid to social justice issues. Although “socially just” is now included in most definitions of sustainable agriculture, blueberry container size along with “environmentally sound” and “economically viable,” Allen believes such issues as living wages, gender inequities, and land tenure are still receiving short shrift. Until such issues are seriously addressed, she argues, a truly sustainable agriculture will continue to elude us. Lack of a coherent message is also a handicap. “One of the major things I try to do in this book is to focus on the way people are thinking about and portraying issues in the sustainable agrifood movement. When you have a social movement that doesn’t have a lot of access to traditional power or resources, your main tool is your ability to frame an issue and convince people of its importance. I feel like the sustainable food movement has not yet done a good enough job of that,” said Allen. Within the movement itself, people are doing all kinds of activities—from running community gardens, promoting locally grown foods, and supporting family farmers, to creating food security councils. According to Allen, “Most people working in these areas recognize that they’re working on a small part of a much bigger issue.

For the movement to become strong and vigorous, there needs to be a coherent, well-articulated platform that bring people together, even thought they’re doing different projects. They need to be meeting the needs of a wide range of people so that people can feel that this movement is for and about them.” Allen addresses this point in the book’s closing chapter, “Working Toward Sustainability and Sustenance,” where she writes – “An articulated vision of a sustainable and food secure society would help engage and unite diverse constituents for an alternative agrifood movement. This is crucial because one of the fundamental requirements of a social movement is a problem statement and a way of expressing that problem—a clear discourse.” With a clear message in place, Allen sees the potential for the alternative agrifood movement to catalyze even larger movements for social and environmental justice—movements in which everyone can play a role. “Participation in the movements need not mean becoming a full-time activist, researcher, or producer. People can participate effectively as consumers by changing their own perceptions and practices . . . Participation in everyday forms of resistance, like choosing foods grown without pesticides, may seem small in comparison to the enormity of the problem, but they can have significant effects.” Together at the Table is part celebration, part cautionary tale, and in the end, a call to action for people working in the alternative agrifood arena to come together and create a democratic social movement with a well-articulated message. “At this point,” writes Allen, “the contemporary American food and agriculture system sustains neither humans nor the environment. Agricultural policy and administrative agencies in their current forms are unlikely to develop effective solutions to problems of poverty, poor health, and environmental degradation.” The alternative agrifood movement has made great strides toward addressing these problems, but must go further to create a truly sustainable system. Together at the Table is geared toward those teaching about agriculture and food system issues, as well as policy makers, activists, and others interested in the transformation of the U.S. agriculture and food system. Aphids’ ability to contaminate a broccoli head has sometimes led to zero-tolerance spray thresholds in conventional broccoli production , thereby causing ecological harm. Minimizing or eliminating sprays for aphids requires knowing more about how they affect broccoli production, and how alternative controls such as natural enemies can affect aphid populations. Diego Nieto, a researcher with the Center, spent two field seasons examining aphid dynamics in an organic broccoli system to determine the way that factors such as the time of the cropping season when aphids arrived, the location of the aphid colony on the plant, and the abundance of natural enemies influenced the broccoli harvest. The study is part of Nieto’s masters’ degree research at San Jose State University. Nieto found that cabbage aphids predominantly colonized the outer leaves of a broccoli plant. These colonies, however, did not significantly influence broccoli harvest. In each of the study’s two field seasons, only aphids located at the center of the plant were correlated with head infestation, making the head unmarketable. Aphid arrival time into a field was strongly correlated with eventual harvest, with early arriving aphids being less likely to infest a head. This was in part due to higher numbers of natural enemies, particularly the larvae of syrphid wasps , which developed in response to the presence of aphids early in the season. Because natural enemies such as they syrphid wasp were able to control aphids arriving early in the season and had a positive effect on the harvest, Nieto recommends that future research on alternative controls for aphids focus on management practices that encourage the early establishment of natural enemies.

These fruits and vegetables displayed time-dependent differences in insect resistance strongly suggesting temporal fluctuations in diverse metabolites, some of which may have important human health impact. Whether continued promotion of circadian periodicity postharvest can also improve longevity of tissue integrity and phytochemical content in diverse vegetables and fruits, as we have shown with kale, cabbage, lettuce, and spinach, remains to be investigated.Plant-based meat is a brand new food category that has attracted widespread media and investor attention since its introduction in 2017. In contrast to other meat substitutes , plant-based meat products are being marketed as indistinguishable in taste and appearance to meat. Producers of plant-based meats aim to compete more directly with, and eventually replace, meat. The appearance of these items beginning in 2017 has drawn a significant amount of interest from environmentalists, conservationists, and animal welfare advocates, as they hope it will result in lower demand for beef and wilderness conversions to pasture required to raise it . The potential is massive. Meat and dairy account for 15% of global greenhouse gas emissions , and the emissions produced by a kilogram of beef can be as much as ten times higher than pork or chicken and twice as high as the second worst offender, lamb . For those concerned about biodiversity, conversion of land to grazing pasture or feed agriculture is the leading cause tropical forest deforestation in much of the world . There is a lack of political will to support the imposition of new taxes on meat products.

Therefore, square plant pots cycling of light treatment with darkness periods may not only maintain clock function but may also avoid physiological damage that may occur in plant tissues under too much light. In addition to improvement of green leafy vegetable appearance by postharvest storage under light/dark cycles, we found that this postharvest storage treatment of plant crops may improve human health benefits through maintenance of phytochemical content . Chlorophyll, responsible for the visual appeal of green leafy vegetables, also has beneficial impact upon human health upon ingestion. Chlorophyll can limit efficacy of carcinogens, such aflatoxin B1 and can activate Phase II detoxifying enzymes. Glucosinolates, sulfurcontaining compounds that play a major role in Brassicaceae plant herbivore defense , also underlie the human health benefits attributed to Brassicaceae vegetable consumption. For example, the glucosinolate glucoraphanin has potent anticancer activity. Previous studies have shown that glucosinolate levels can be maintained by refrigeration or exposure to radiation; here we find that post-harvest storage under light/dark cycles can also lead to sustained glucosinolate levels .Light/dark cycles also maintain the circadian clock function of other edible crops after harvest, including zucchini, carrots, sweet potatoes, and blueberries.

As such, the only viable strategy for plant-based meat to gain market share from traditional animal-derived meat is to compete on price and taste. Some futurists have suggested that technological advancements may make this inevitable in the future , but currently PBM is far more expensive. While alternative protein sources have gained market share in recent years, it remains to be seen whether they will be able to replace their animal-based Researchers have sought to better understand the potential for PBM, but because it is so new, much work has been limited to stated preference surveys, which rely on hypothetical choices. Researchers have generally found that even if offered large price reductions, the market share for PBM is likely to stay below 20% of ground meat . Research that takes advantage of retail scanner data has sought to examine substitution patterns, but without individual level data, can only say limited things about who the customers are . Many of the existing stated preference studies identify those already predisposed to meat alternatives as the most likely to purchase PBM, and also find a not insignificant amount of the demand comes from those being pulled into the meat market , yet researchers have also found that most PMB purchasers also bought meat or ground meat. Understanding both who PBM purchasers are in the real world and how their consumption is affected is critical to understanding if PBM has a real potential to replace beef and other meats, or if PBM is simply a new category of meat alternative that is mainly competing with other kinds of low emissions foods like veggie burgers, tofu, or chicken. As data availability has increased some researchers have been able to use household scanner data to begin to answer these questions, but there are limited sample sizes due to the small size of PBM market share.

In particular, this work has shown us that PBM purchasers did not reduce their ground beef purchases after they first bought PBM, and that just more than half of PBM purchasers bought it again . This paper has the advantage of proprietary data from a nationwide grocery chain that goes beyond home scanner data. With this data, I am able to draw a very large sample of households who have bought PBM at least once and have a long history of their purchases before and after. With this dataset, I am able to draw more fine conclusions about what attributes are related to purchasing and repurchasing PBM, as well as if PBM is able to spread to customers who are more likely to be substituting away from meat. In addition, because of how promotional pricing is determined at this nationwide chain, I am able to run event study regressions to test the theory that PBM has is a robust substitute for beef in grocery stores.The data for this study are proprietary data from a single nationwide grocery store chain, which operates in a number of different regions and under a number of different store ordividion names. Over 90% of sales across all brands are linked to an individual membership card that is theoretically assigned to a single household, although some people may share their membership card. When a customer applies for a membership card, some but not all have provided certain information that has allowed the grocery chain to match them with data from a credit company who provides estimates of the head of household’s age and race1 , and the size and income of the household. Prior studies using person level scanner data have been limited by the number of households that have ultimately purchased plant based meat. In order to ensure a large sample size, every household that purchased plant-based meat from its first limited introduction in 2017 to the end of 2019 was included, and a random sample of all households who did not purchase PBM in the same period was included as a comparison. While PBM was only first introduced in limited stores in mid 2017, all purchases since the beginning of 2016 are included in the data. This allows me to characterize households by their purchases in prior periods, as well as flexibly examine what types of purchases could ultimately predict who will buy PBM and who will rebuy it, plastic potting pots with the ultimate aim of trying to better understand if PBM are attracting the types of customers who are likely to substitute it for real meat. About 40% households did not have a full credit data match, either because they did not share enough data when they signed up for their membership card to be linked in the credit company’s database, or because one of the demographics estimates was missing for other unknown reasons. Households whose first trip was later than the 12th week of 2016 and whose last trip was before the 40th week of 2019 were also dropped. The spread of average trips per week per household between those that had and those who hadn’t bought PBM were found to be fairly different. This makes intuitive sense, as households that recorded few trips were more unlikely to have purchased any specific product item coded as a UPC. As a result the sample was trimmed to make the distribution of trips more similar: only households with more than 0.85 trips per week and less than 5.85 trips per week were included.

After all these cuts, we were left with 134,167 households who had bought PBM at least once and 60,269 households that had never bought PBM. In order to test if political partisanship has had an effect on demand for PBM, an additional demographic variable was created by connecting the zipcode of the most frequented store by each household to precinct level voting data from the 2016 presidential election compiled by the New York Times. Because the precinct that a store is in might be different from the surrounding area, the percentile Clinton vote of each precinct’s surrounding area is used, which the New York Times describes as “a measure based on the choices of the nearest 100,000 voters, as well as those within a 10-mile radius”. Plant-based meat beef were first rolled out in select areas in mid 2017, so the entire 2016 year is used as a pre-period to establish what households spent their money on before PBM existed. Five different pre-period variables were created due to assumptions of importance. Four variables were defined as the percent of expenditures in the pre-period that were spent on meat, ground beef, veggie burgers, and tofu. In addition, a household specific low meat indicator was defined as equal to one if a household spent less than 5% of expenditures in the pre-period on any meat. In order to expand the potential important relationships of pre-period purchases to not just the four goods of interest, but to any goods, two levels of UPC categorization used by the grocery chain were used. All UPCs are organized into 57 ’Groups’ and the more specific 459 ’Categories’ and those divisions were used for percent of expenditures in the pre-period calculations.There are three outcomes of interest: buying plant-based meat, rebuying PBM, and the changing demographics of who is buying PBM for the first time. Simply buying PBM is of obvious interest, but rebuying it may be even more important. If PBM is going to replace real meat, it will have to become a regular part of customers’ market basket. Simply knowing who the buyers and rebuyers of PBM are will not in itself provide a causal estimate of how much meat we expect PBM to replace, but it can tell us how optimistic we are about its ability to outcompete meat. Even the most optimistic PBM evangelists do not expect PBM to make a large dent in meat sales this early in its existence, but they do often cite the fact that 80 to 90% of PBM customers also eat meat. The implication is that PBM is not just for vegetarians, but will slowly muscle out meat in these customer’s diets. While this simple fact has been shown to be true, a much closer look at who is buying and rebuying PBM will tell us more about its potential as a meat killer. Because I observe grocery sales up until the last day of 2019, however, some customers have far longer to rebuy from their first purchase than households that bought near the end of 2019. If I used a simple 1/0 variable of rebuy, then I would find that early first time buyers were far more likely to have rebought, but as will be discussed in the next paragraph, there is reason to believe that later first time buyers may be different from earlier ones, so if this timing issue is not corrected for, we may mistake these changes in who is in the market for PBM as related instead to who is rebuying it. Therefore, I limit the rebuy decision to 12 weeks after the first buy for each household, and I drop all households who bought their first PBM item within 12 weeks of the end of 2019. Less obvious is why I care about the timing of when households first bought PBM. The proponents of PBM market it as not a better veggie burger, but as a whole new category of food, so the data are witnessing how a brand new option enters the grocery market. In mid 2017, when PBM was first offered for sale on grocery store shelves, it would not be surprising if many of the first time customers were highly knowledgeable about meat and animal alternatives and that those purchases were unlikely to be replacing much meat. That, however, is much less important than how the market evolves.

Conversely, warmer temperatures may lead to increased exposure to pathogens and pests or to reduced survival due to intensifying summer droughts or extended winter freeze–thaw cycles . It should be noted that any herbarium-based study of this magnitude is susceptible to the criticism that it includes potentially faulty records, either because of differing biases among collectors in the timing and location of collection, or because of limited documentation of the error distances associated with georeferencing of each specimen. Previous examinations of herbarium collections have found, for example, that collection effort is often concentrated at locations that are easily accessed and may also avoid periods of severe inclement weather such as intense storms or blizzards . However, multiple studies have determined that estimates of phenological change keep pace with estimates of phenological change derived from in situ data sources, indicating that collector preferences in the timing of collection are unlikely to produce systematic bias in the resulting estimates of flowering time or phenological advancement . Similarly, while the rarity with which estimates of georeferencing accuracy are recorded in digital specimen data limits our ability to directly analyze the effects of georeferencing errors on this analysis, blueberry pot such errors are more likely to be a source of noise rather than of systematic bias in a study of this scale.

To produce systematic biases in the resulting data, locations associated with large error distances would be required to be biased toward locations with frost risks that differed in a specific direction . Furthermore, such biases would be required to persist across records produced and georeferenced by many different collectors and multiple independent institutions, all of which would be required to exhibit similar directional or climatic biases. It should also be noted that these results represent broad regional patterns in frost risk among 1,653 taxa across a large portion of the continental US. As this study documents, a significant proportion of taxa have exhibited increased frost risk post-1979. While beyond the scope of the current study, certain regions or floras have likely exhibited lesser reductions in frost risk than were observed across the broad spatial scales examined in this study. Furthermore, examinations of frost risk to various crop species have indicated that microclimate variations that occur at smaller scales than can be observed in this study may also play significant roles not only in determining local temperature but also in the process of ice nucleation, thereby affecting the resulting risk of frost-related damage to plant reproductive tissues . Nevertheless, the results presented here are consistent with broad-scale models of past and present frost risk to vegetative tissues among native tree species , indicating that, for the majority of species and in the majority of locations, frost risk to reproductive tissues is likely to be decreasing as a result of progressive climate changes.

While the effects of these changes will likely produce complex impacts on fruit and seed production across taxa and throughout North America, understanding the degree to which broad, systematic shifts in frost risk, phenology, and other ecological processes are occurring among taxa in response to recent climate change remains critical to understanding the broad-scale effects of climate change. Broad generalizations about the phenology of a flora at regional or continental scales, however, require historical data that are both temporally deep and spatially extensive. By leveraging the wealth of data presented by herbarium specimens and other natural history collections data, we may seek and identify broad, climate-driven patterns in reproductive phenology . By demonstrating that recent warming has produced a systematic reduction in frost risk to floral tissues throughout the North American flora, this study highlights a critical aspect of the effects of future climate change, and the likelihood that future warming will further reduce frost risk across the majority of taxa across North America.ISmith, 2019. Nevertheless, the results presented here are consistent with broad-scale models of past and present frost risk to vegetative tissues among native tree species , indicating that, for the majority of species and in the majority of locations, frost risk to reproductive tissues is likely to be decreasing as a result of progressive climate changes. While the effects of these changes will likely produce complex impacts on fruit and seed production across taxa and throughout North America, understanding the degree to which broad, systematic shifts in frost risk, phenology, and other ecological processes are occurring among taxa in response to recent climate change remains critical to understanding the broad-scale effects of climate change.

Broad generalizations about the phenology of a flora at regional or continental scales, however, require historical data that are both temporally deep and spatially extensive. By leveraging the wealth of data presented by herbarium specimens and other natural history collections data, we may seek and identify broad, climate-driven patterns in reproductive phenology . By demonstrating that recent warming has produced a systematic reduction in frost risk to floral tissues throughout the North American flora, this study highlights a critical aspect of the effects of future climate change, and the likelihood that future warming will further reduce frost risk across the majority of taxa across North America.are above 53.5°F . During the first flight, the female glues single eggs to flat surfaces on or near the flower cluster; second and third-generation eggs are laid on grape berries. Larvae form webbed nests; the first-generation larvae feed on flowers before and during bloom in Northern California; second-generation larvae feed on green berries; and third-generation larvae feed inside ripening berries. Larvae create distinctive round holes in prebloom flowers and ripening fruit, which distinguishes their feeding damage from that of other common Lepidoptera larvae found in California vineyards . Feeding damage to berries by second- and third-generation larvae exposes them to infection by Botrytis and other secondary fungi that can be economically damaging.On October 7, 2009, USDA confirmed the presence of EGVM in Napa County. A federal order issued by USDA in June 2010 initiated a quarantine area within 5 miles of all detections . Detections were defined as two or more adult moths trapped within 3 miles of each other during the same life cycle or immature stages confirmed to be EGVM by DNA analysis. The order indicated plant host species as well as plant parts, products, farming and processing equipment, and green waste residues as regulated articles that could not be transported interstate from a quarantine area except under specific conditions. The state interior quarantine enforced restrictions parallel to those in the federal order for intrastate movement of regulated articles within or from quarantine areas. In 2012, the quarantine buffer was reduced from 5 miles to 3 miles around detections. This change accommodated the program’s need to reduce the cost of implementation while acknowledging the adult moths’ short-distance natural dispersal .Immediately after the first confirmed detection in 2009, USDA, CDFA and the Napa County agricultural commissioner deployed 248 sex pheromone–baited traps to delimit the population. However, very few moths were caught because traps were deployed at the end of the third flight . In addition to the trap captures, ground surveys in 2009 recorded 26 larvae, eight pupae and one female at multiple sites in two distinct areas of Napa County. As a result, nursery pots the state interior quarantine was established in March 2010, over an area totaling 162 square miles in Napa County . In February 2010, trapping efforts expanded throughout all grape-growing regions of California — roughly 803,000 acres . Traps were deployed at densities of nine to 16 or 25 traps per square mile of planted vineyard outside and inside the regulated area, respectively . In select urban areas, traps were placed on potential EGVM host plants at a density of five traps per square mile . By the end of 2010, the quarantine area included portions of eight California counties, totaled 2,091 square miles and contained approximately 150,760 acres of vineyards . Subsequently, in 2011, traps detected moths in two additional counties, bringing the total number of regulated counties to 10 and a peak quarantine area of 2,335 square miles .

Trap captures in Napa County indicated a large, widely distributed population, whereas populations in other counties were significantly smaller and more contained . The EGVM regulatory program has relied heavily on the use of pheromonebaited sticky traps to detect moth populations. UC scientists evaluated the efficacy and longevity of four pheromone lures in replicated field experiments in Napa during the first and second moth flights of 2010 . All lures were effective for monitoring EGVM male moth populations during and beyond the period recommended by the manufacturer .In November 2009, USDA assembled a technical working group of subject-matter experts to provide urgent scientific recommendations to regulatory program managers in California. The TWG included university scientists from Italy, France, Germany, Spain, Chile and California, as well as USDA scientists and a representative of the wine grape industry. TWG members continue to meet annually to review program activities and provide technical expertise on topics as diverse as insect biology, detection strategies, handling of harvested fruit and winery waste, and management activities. Since 2010, TWG members have agreed that eradication of EGVM from California remains a realistic goal as long as the population did not become substantially more widespread than was known at that time, the grape industry remained supportive of the effort and effective control methods were available for use by the program . Over the course of the EGVM program, TWG members evaluated research data and program developments to formulate recommendations based on the insect’s biology. Government agencies matched these recommendations to political and fiscal analyses to formulate and deliver the EGVM program.Treatment areas. Treatment areas were defined within a requisite distance from all detections and included agricultural, residential and commercial properties. In 2010, the distance was not standardized, so the size of the treatment areas varied by county. Following a review of the scientific literature suggesting that EGVM are short-distance fliers, the TWG recommended a treatment area within 1,640 feet of all detections regardless of when the detection occurred. From 2013 onward, the TWG modified this recommendation to account for timing of the detection: Treatment areas came to be defined as within 500 m of detections occurring in the current year and previous 2 years. Within the treatment areas,grape and olive were the targeted hosts of concern, and total vineyard acreage varied considerably by county and year . The specific combination of tools used in treatment areas differed by land use and occurrence of potential host plant species. Insecticide program. The recommended insecticide program for EGVM in California vineyards targets the eggs and larvae and includes at least one application of a conventional insecticide or at least two applications of an organic insecticide for each of the first two generations . Although treatment of the first generation is not typical in the Palearctic regions, the TWG determined that treating the first two generations in California would provide the greatest opportunity to eradicate populations. In early 2010, UC scientists provided an exhaustive list of potential insecticides for EGVM management based on a review of the scientific literature. From this list, EGVM program leaders made a concerted effort to identify and recommend products that would provide selective control of EGVM while minimizing risks to nontarget organisms and the environment. The availability of organic treatment options ensured that growers could maintain organic certification while complying with the eradication effort. Pesticide use reporting data for Napa County indicate that growers used a combination of the recommended materials . Insecticide efficacy trials. UC scientists conducted field trials in commercial vineyards in Napa in 2010 to evaluate the efficacy of registered insecticides for EGVM. Chlorantraniliprole, methoxyfenozide, spinosad and Bacillus thuringiensis provided control of young larvae; abamectin, indoxacarb and spinetoram provided the best control of mature larvae . These results were widely distributed to the program team and grape growers. Insecticide treatment. Selective insecticides are most effective if applied when the pest is at its most susceptible stage . In Napa County, UC scientists monitored the male flight, egg and larva development and calculated degree-days from a biofix of January 1 for each life stage . Referencing these observations and calculations to local weather data and vine phenology, UC scientists then determined the optimal timing for insecticide applications for all affected locations in California.

The rationale for doing so was to realistically simulate the consumption of BBs with an MHF meal while maintaining the same nutrient composition of each test meal. A registered dietitian designed the pretest dinner and the MHF breakfast by using the Nutrient Data System for Research software version 2011, developed by the Nutrition Coordinating Center of the University of Minnesota in Minneapolis, Minnesota and ProNutra software. The BB powder was provided by the US Highbush Blueberry Council and was composed of a 50/50 mixture of 2 varieties of highbush BBs, Tifblue and Rubel . Whole BBs were freeze-dried, milled, and stored in sealed aluminum cans with a desiccant at 220 C. The placebo control powder and 2 different servings [2 and 4 servings] of BB powder preparations were made to match: color , flavor , fat , carbohydrates , protein , and fiber , and vitamin C of the preparation containing 4 servings of BB powder . Nutrient content was confirmed by chemical analysis at Medallion Labs.EDTA-treated plasma was collected at fasting and postprandial blood draws and concentrations of plasma cytokines were determined by using the Human ProInflammatory II 4-plex ultra-sensitive kit from Meso Scale Discovery. Plasma glucose and serum TGs, total cholesterol, growing blueberries in pots and HDL cholesterol were measured by using standard clinical chemistry techniques on a COBAS Integra 400 plus analyzer according to the manufacturer s instructions . Serum FFAs were measured by using NEFA-HR2 reagents on the COBAS Integra 400 plus.

LDL cholesterol was calculated by using the Friedewald equation . Serum insulin was measured by using an Immulite analyzer .Humans spend the majority of the day in the postprandial state. Increased plasma TGs, insulin surge, and accompanying decrease in plasma FFAs are general features of immediate postprandial changes in blood . Decreased postprandial plasma FFA concentrations are generally preceded by a meal induced postprandial insulin surge, which suppresses lipolysis and stimulates re-esterification of FFAs into TGs. Whether and how plasma concentrations of FFAs modulate postprandial inflammation are not clear. Saturated FAs can activate TLR2 and TLR4 leading to the expression of markers of inflammation in cell culture systems . TLR2- or TLR4-deficient mice were protected from high saturated fat diet-induced inflammation and insulin resistance , suggesting that saturated FAs derived from dietary fat can induce TLR-mediated inflammation. The concentrations of plasma FFAs and TGs are temporally regulated in concert with endocrine changes in fasting and postprandial states. Our previous mechanistic study showed that both exogenous palmitic acid and endogenous FFAs, hydrolyzed by added LPL from TGRLs isolated from human subjects who consumed a high fat meal, induce the activation of TLR2 in primary blood monocytes and whole blood . TLR2 activation was assessed by the receptor dimerization and the expression of the monocytespecific TLR2/inflammasome-mediated IL-1b as a biochemical readout. Treatment of primary monocytes or whole blood with LPL also caused increased expression of IL-1b, providing a mechanistic insight for the causal role of plasma FFAs on cytokine production .

Together, these results suggest that the concentration of plasma FFAs is an important determinant for the expression of TLR target gene products in blood monocytes and possibly other blood leukocytes that express TLR2 or TLR4. The results of our current study show that the concentrations of cytokines decreased in 3.5-h postprandial plasma after the MHF breakfast as the concentrations of FFAs declined compared with those of fasting plasma , suggesting that eating breakfast may attenuate acute postprandial inflammation. However, when postprandial blood samples were treated with LPL, the pattern of FFA and cytokine concentrations was reversed. The FFA concentrations of LPLtreated postprandial blood samples were greater than those of LPL-treated fasting blood samples . Similarly, the cytokine concentrations from PBMCs incubated in postprandial autologous plasma treated with LPL increased compared with those from PBMC incubated with fasting plasma . The concentrations of IL-1b in postprandial whole blood treated with LPL were also increased compared with those from fasting whole blood treated with LPL . Taken together, the results from the current study and our previous mechanistic study reveal that plasma FFA concentration may be an important modulator of cytokine production in human blood. The decreased FFA concentrations in postprandial plasma compared with fasting plasma may result from the postprandial surge of insulin, which suppresses lipolysis and stimulates esterification of FFAs to TGs , leading to decreased production of cytokines. Other studies showing varying results on postprandial cytokine concentrations have not focused on the relation of the postprandial cytokine concentrations with those of plasma FFAs. Such varying results may reflect in part differences in sampling time of postprandial blood, dietary composition, and heterogeneous health status of the subject populations.

The subjects enrolled in our study were mostly young and generally healthy, with a BMI of 18–25, reflecting a relatively homogeneous group. Saturated FAs are the predominant FAs esterified in TGs of TGRLs isolated from subjects who consumed a meal high in saturated fat . Thus, the result that increased plasma concentrations of endogenous FFAs released by the treatment of LPL correlated with elevated production of cytokines in the blood samples suggests that saturated FAs in the FFA fraction predominate in modulating proinflammatory signals in blood. The breakfast meal used in this study contained 14.3 g of saturated fat, which represents 19.8% and 15.3% of the total calories from the breakfast alone and breakfast plus BB powder, respectively. Thus, the saturated fat content is more than twice the level recommended by the American Heart Association. The reason for using the elevated level of saturated fat was that, because saturated FAs can induce TLR-mediated monocyte activation, we intended to use this breakfast as a challenge meal. In spite of such a high saturated fat content of the breakfast, the postprandial plasma FFAs and cytokine concentrations declined compared with those of the fasting plasma. This result suggests that a meal-induced insulin surge may predominate in regulating plasma FFAs and, in turn, FA-induced cytokine production in healthy subjects given the type of breakfast described in our study. The surface expression of adhesion markers CD11b/c and CD14 were increased after treatment of whole blood with LPL . This result further supports the possibility that plasma FFAs derived from dietary fats can activate monocytes and may lead to increased adherence of monocytes to vascular endothelial cells. The concentrations of TGs in postprandial plasma were greatly increased compared with those of fasting plasma . FFAs, not TGs, can induce the expression of the TLR target gene product, COX-2 in macrophages . This finding is consistent with the result that the concentrations of postprandial cytokines follow FFA levels but not TG levels. Plasma FFAs are derived from TGs in adipose tissue and in part from dietary fat. However, in a microenvironment where TGRLs are exposed to LPL secreted from endothelium, local concentrations of FFAs can be increased before FFAs are taken up by endothelial cells for re-esterification to TGs or incorporation into lipid droplets . Thus, cell surface TLRs expressed in blood monocytes will be exposed to the increased FFAs and can subsequently be activated, leading to production of proinflammatory gene products including cytokines. Therefore, elevated plasma TGs could enhance the propensity of monocyte activation. Polyphenols are extensively metabolized by gut microbiota, enterocytes, and liver enzymes . Postprandial whole blood should contain any nonmetabolized polyphenols and their metabolites derived from the ingested BB powder. Therefore, to assess the effects of these absorbed polyphenols and their metabolites on TLR-mediated monocyte activation, fasting and postprandial whole blood were stimulated with endogenous FFAs derived from plasma TGs by LPL treatment in this study. Certain polyphenol compounds found in fruits and vegetables can inhibit the activation of pattern recognition receptors . BBs contain high concentrations of these polyphenolic compounds including anthocyanins . Cyanidin-3-glucoside and their metabolites suppress LPS-induced cytokine production in THP-1 monocytes . BB supplementation did not affect postprandial FFA and cytokine concentrations ; however, drainage gutter it attenuated the propensity of monocyte activation induced by elevated concentrations of FFAs in LPL-treated blood ex vivo . Supplementation with 2 and 4 servings of BBs with the breakfast meal resulted in decreased LPL-induced secretion of IL-1b and IL-6, respectively, in postprandial whole blood without affecting concentrations of FFAs released . These results suggest that the consumption of BB powder with the breakfast meal could decrease the propensity of postprandial monocyte activation in the microenvironment where blood monocytes directly interact with endothelial cells that secrete LPL.

The inhibitory effect of the BB powder on LPL induced cytokine production is likely due to the inhibitory effects of polyphenols on FFA-induced activation of pattern recognition receptors including TLRs rather than potential offtarget effects on LPL because BB intake did not alter the concentrations of FFAs released. It was reported that intake of strawberries , orange juice , tomatoes , or blackcurrants with a high-fat meal was cardioprotective by decreasing selective inflammatory markers . Because postprandial FFA concentrations may change in time, the impact of polyphenol-rich BBs on FFA-induced postprandial inflammatory status will need to be studied in the future with blood samples taken at multiple time points, including the period when FFA concentrations rebound close to or exceed fasting concentrations. The study has several limitations. The study was not powered to look at interactions between sex and consumption of BB powder. In addition, the subjects were allowed to return to their normal daily activities after consumption of the test meal until their return for the postprandial blood draw. Because sex differences and physical activity could have affected postprandial responses, recruitment strategies to create a balanced sex distribution and control of physical activity may need to be implemented in future studies. In summary, consumption of an MHF breakfast decreased postprandial plasma FFA and cytokine concentrations compared with those of fasting plasma, suggesting that eating breakfast acutely attenuates the inflammatory status in postprandial blood. Plasma FFA concentrations may be an important determinant modulating monocyte activation as assessed by TLR-mediated IL-1b secretion and the expression of adhesion molecules . These results corroborate the results from our previous mechanistic studies that both palmitic acid and endogenous FFAs can directly activate TLR2 and induce the expression of proin- flammatory cytokines in primary monocytes and whole blood. A corollary of these results is that the concentration of plasma FFAs may be one of the important determinants affecting the inflammatory status in blood. Thus, our results lead to the next translational question as to whether plasma FFA concentrations can be a target of dietary or pharmacological intervention to alleviate the increased inflammation in metabolic diseases. Supplementation with BB powder did not affect the postprandial FFA and cytokine concentrations; however, it suppressed FFA-induced cytokine production in LPL-treated blood.Grapevine berry ripening can be divided into three major stages. In stage 1, berry size increases sigmoidally. Stage 2 is known as a lag phase where there is no increase in berry size. Stage 3 is considered the ripening stage. Veraison is at the beginning of the ripening stage and is characterized by the initiation of color development, softening of the berry and rapid accumulation of the hexoses, glucose and fructose. Berry growth is sigmoidal in Stage 3 and the berries double in size. Many of the flavor compounds and volatile aromas are derived from the skin and synthesized at the end of this stage. Many grape flavor compounds are produced as glycosylated, cysteinylated and glutathionylated precursors and phenolics and many of the precursors of the flavor compounds are converted to various flavors by yeast during the fermentation process of wine. Nevertheless, there are distinct fruit flavors and aromas that are produced and can be tasted in the fruit, many of which are derived from terpenoids, fatty acids and amino acids. Terpenes are important compounds for distinguishing important cultivar fruit characteristics. There are 69 putatively functional, 20 partial and 63 partial pseudogenes in the terpene synthase family that have been identified in the Pinot Noir reference genome. Terpene synthases are multi-functional enzymes using multiple substrates and producing multiple products. More than half of the putatively functional terpene synthases in the Pinot Noir reference genome have been functionally annotated experimentally and distinct differences have been found in some of these enzymes amongst three grape varieties: Pinot Noir, Cabernet Sauvignon and Gewürztraminer. Other aromatic compounds also contribute significant cultivar characteristics. C13-norisoprenoids are flavor compounds derived from carotenoids by the action of the carotenoid cleavage dioxygenase enzymes.

We were able to detect these patterns even though the resolution of the remote sensing data was limited to 250 m. As remote sensing data technology advances, we will be able to further explore these patterns. There are clearly different patterns of bee abundance between land use types over the course of the year. We detected differences in land surface phenology between land use types through remote sensing, although the relationship between remote sensing vegetation indices and the bee community is complex due to the role of seasonality and major differences in vegetation between land use types. The strongest relationship between vegetation indices and bee abundances were in natural sites, but sites classified as natural also exhibited high colinearity between seasonality and vegetation indices, making it difficult to tease apart the differences. The overlapping points between seasons in the urban and agricultural areas mean that vegetation indices are less tied to seasonality. Despite this lack of colinearity with seasonality in human-altered landscapes, there were still significant patterns between vegetation indices and bee abundance, square pot indicating the potential to use remote sensing to detect certain aspects of biodiversity. Further exploration into the relative contributions of different types of vegetation within each land use type and between time of year would contribute to the strength of applying these findings more broadly.

In addition,building on the idea of “scaling up from urban gardens”, it would be valuable to see if patterns change when the larger surrounding area of each location is investigated. No significant relationship was detected between vegetation indices and species richness as a general indicator, although focusing on certain species or functional groups may highlight which are more vulnerable to changes in phenological patterns. In this study, bee collections were made approximately every two months, yet certain species peaked in abundance at different times between land use types. This lack of synchrony in peak abundance between land use types could be the result of two possibilities: either bees are moving between land use types in search of better resources, or localized population structuring is occurring between different land use types based on differences in timing of emergences. Perhaps on a finer temporal scale of collections, for example, on the same frequency as MODIS composite products , these subtleties in timing between land use types could be better captured. Additionally, the role of time lags should be further explored by investigating floral resource availability. We found better fitting models with increasing time lags, although this may still be tied to the strong effect of seasonality in natural areas. However, several other studies have shown the importance of time lags between changes and ecological responses. In our case, this is likely the result of challenges in using vegetation indices as proxies for floral availability. Sometimes extreme floral abundance can lead to an underestimation of vegetation biomass. Perhaps our time delay is the result of plants experiencing green up through leaf growth before producing floral reproductive structures. A better understanding of species associations with vegetation indices would further improve predictive power of utilizing remote sensing data to predict species distributions.

These findings have implications for how we think about human-altered landscapes and restoration. A great amount of interest and resources go into creating “green spaces” and restoring patches of land within urban and agricultural matrices. However, most restoration practices are based on studies in more natural land use contexts. Due to the much higher degree of patchiness in human-altered landscapes and changes in phenological patterns, restoration goals and strategies may need to be altered when working in human-altered landscape contexts. Additionally, this study highlights the importance of temporal differences in human-altered landscapes. Understanding how human-altered landscapes impact species distributions and interactions is critical as land use change accelerates globally. In order to overcome previous limitations when using remote sensing to estimate biodiversity, it is first important to further understand the dynamics of vegetation type, phenology, and the ecology of interacting taxa. Our results clearly indicate that the phenology of vegetation in different land use types are not synchronized, and vegetation indices created through remote sensing can predict bee community abundance. Such findings suggest the potential to use remote sensing to estimate other taxa beyond bees to estimate biodiversity, as well as provide a new way of understanding the ecological challenges of urbanization and agriculture due to phenological differences.Human-altered landscapes are expanding globally and are often associated with declining natural habitat, non-native species, fragmentation, and transformations in structure, inputs, climate, and connectivity. These changes collectively have resulted in shifts in both spatial distributions and species diversity across many taxa including birds, mammals, reptiles, amphibians, invertebrates, and plants. One common driver of global change is urbanization, which in the extreme is associated with a reduction in biodiversity compared to habitats in their more natural state.

However, in moderately urbanized areas, the effects of urban impacts on species distribution and diversity can vary greatly and depends on region, type of change, and taxonomic group, among other factors. Documenting the effects of urbanization compared to natural communities has proven problematic, making predictions of community change associated with urbanization difficult. Human-altered landscapes are often associated with many non-native species which add to species diversity but also can obscure changes in community dynamics. Thus, to assess accurately the complex impacts of land use change on ecological communities, one must look beyond species richness to investigate ecological processes themselves. Ecological processes are the links between organisms in a functioning ecosystem, and are critical in understanding how altered biodiversity can lead to changes in ecosystem functioning. Global environmental change has been found to have a wide variety of impacts on ecological processes in different systems. Pollinator-plant relationships in particular are found to be particularly vulnerable to land use change, resulting in decreases in interaction strength and frequency. Pollination services are crucial ecosystem processes in natural systems, but also in agricultural and urban areas. Bees provide the majority of animal mediated pollination services on which it is estimated 87.5% of flowering plants depend. The value of pollination in agriculture is estimated at $200 billion worldwide, largely due to many foods that are essential for food security and a healthy human diet, including numerous fruits, vegetables, and nuts that require bee pollination. As urban areas expand, there has been increasing interest in urban agriculture to ensure food security and access to healthy foods for growing populations, and these systems also depend on pollination. For example, Kollin estimated that the economic value of urban fruit trees to be worth $10 million annually in San Jose, California. Despite the important role of pollinators and concerns about bee declines, there remain many uncertainties regarding the impact of land use change on pollinators. Urbanization has resulted in more interfaces with both natural and agricultural landscapes, creating new transitional zones of peri-urbanization. While there has been extensive pollinator research in agricultural and natural systems, less attention has focused on pollination in neighboring urban areas and how the changing landscape has impacted pollination. In addition, square plastic planter very few studies of urban areas have looked beyond changes in bee diversity to understand explicitly the effect of urbanization on pollinator-plant interactions. Here, we investigate the effect of land use change on pollinator-plant ecosystem processes. We make use of a “natural experimental design” in which urban, agricultural, and natural areas intersect. Bees visit flowers for both pollen and nectar resources, and floral visitation is a commonly used as an index of pollination services. However, depending on the flower, certain bee groups are much more effective pollinators than others.

Thus,while visitation is important, it alone does not definitively indicate whether pollination services were received by the plant. When pollen is limited by other factors, consequences for plant fitness can include failure to set seed, production of smaller fruits, and even complete lack of reproduction. By looking at rates of bee visitation and comparing this with other measures of plant fitness, such as seed set, we can develop a more complete understanding of how shifts in bee distributions between areas that differ in land use are impacting pollination services. To study the impact of changing land use on pollinator-plant interactions, we focus on bee pollination of a widespread plant, yellow starthistle , a common weed found in natural, agricultural, and urban habitats. Using standardized observations of floral visitation and seed set measurements of yellow starthistle, we test the hypotheses that increasing urbanization decreases 1) rates of bee visitation, 2) viable seed set, and 3) the efficiency of pollination . In addition to contributing to a better understanding of how change in landscape use, particularly urbanization, affects pollination-plant interactions, the study illustrates the importance of use of neighboring lands for pollination services.Our study system was located around Brentwood, in east Contra Costa County, California, where natural, agricultural, and urban areas intersect with each other within a 20 x 20 km region . A county water district , regional park district , and California state park all fall within the region, leaving large areas of land protected from development. This protected land consists mainly of grasslands and oak woodlands, some portions of which are managed for grazing. The agricultural areas of Brentwood, Knightsen, and Byron mostly consist of orchards , corn, alfalfa, and tomatoes. A housing boom in the 1990s led to massive residential growth in the area. The city of Brentwood has grown from less than 2500 people in the 1970s to over 50,000 today , and nearby Antioch has now over 100,000 residents . We selected 12 sites dominated by yellow star thistle in a stratified design to span the different land use types . Yellow starthistle is a common weedy plant that forms homogenous flowering patches in grassy areas throughout this region. Many different bee taxa in a range of functional groups and size classes have been observed to visit yellow starthistle, in part because it flowers late in the season relative to other floral resources. Despite being considered a serious introduced weed, yellow starthistle is unusual as an invasive species in that it depends on animal pollinator visits in order to set seed.Within each site we selected a 50 m x 50 m plot such that each plot was at least 2 km away from all others, a distance larger than the maximum assumed typical bee foraging ranges. Although certain bee species have been recorded foraging as far as 1400 m, most bees in this type of habitat have nesting and foraging habitat within a few hundred meters of each other. Within each plot we estimated number of flowering yellow starthistle blooms by randomly placing 10, 1 m x 1 m quadrats and counting the number of flowering blooms in each. We also measured the spatial area of yellow starthistle patches within each 50 m x 50 m plot to obtain an estimate of total flowering blooms within each plot. We categorized total blooms/plot on a log scale: <103 , 103 -104 , and >104 . Using NOAA’s 2006 Pacific Coast Land Cover dataset , a 500 m buffer was created around each plot, and the number of pixels classified as agricultural, urban, natural, water, or bare land was extracted. Because each site had an AM, Mid-Day, and PM observation event, there were a total of 36 observation events, each with unique wind and temperature recordings, and visit observations of the 15 bee morphotypes. From these, we calculated the total number of bee visitors, total number of bee morphotypes, Shannon diversity of morphotypes, and morphotype evenness. Shannon diversity and evenness were calculated using the R package vegan. The spatial autocorrelation of all bee visitor response variables was assessed by Mantel tests in R package ade4, using the average values for each time of day at each site. Spatial autocorrelation was not detected . To test for the effect of land use type on each of the response variables we used a generalized linear mixed model using the R package lme4. We designated land use type, bloom category of flowering patch, observation time period, wind, and temperature as fixed effects and site as a random effect. Natural land use and AM observation time period were the model baselines for the categorical variables of land use type and observation time.

A more plausible explanation for the presence of ToRSV in the experimental orchard site is that this virus occurred in alternative plant hosts, likely in weeds, prior to the establishment of the pawpaw trees. Then, X. americanum-mediated ToRSV transmission may have occurred from infected weeds to some pawpaw trees and saplings. This hypothesis is further supported by the fact that ToRSV was not identified in symptomatic leaf samples from a pawpaw orchard in Maryland where the virus may not be present. Interestingly, dual infections by TRSV and ToRSV were detected in leaf samples of tree #1 and its sapling, and in flowers of tree #2 . This result may suggest that ToRSV infection in flowers of tree #2 may have resulted from pollen-mediated inoculation. Sequence analyses following HTS and Sanger sequencing of RT-PCR amplicons revealed a close genetic relatedness of TRSV and ToRSV isolates from pawpaw based on a high nucleotide sequence identity in a partial RdRP fragment . A similar high nucleotide sequence identity was found between pawpaw isolates and isolates from other crops . For the partial CP fragment and 30 -UTR of ToRSV, the nucleotide sequence identity was high among isolates from pawpaw but lower between pawpaw isolates and isolates from other crops . Nonetheless, the percent nucleotide sequence identities determined for the ToRSV isolates from pawpaw in the partial RdRP, CP, 25 liter pot and 30 -UTR fragments fall within the ranges previously reported.

Declining pawpaw trees were reported in the late 1990s from Oregon. A disease origin of the decline was suspected but no pathogen, particularly no fungi or bacteria, was consistently isolated from declining trees. Curiously, viruses were not investigated in this work. Our study is the first to ever report the occurrence of a pathogen in symptomatic pawpaw trees with the identification of ToRSV and TRSV. The fact that these two nepoviruses were found in symptomatic trees and some of their saplings was consistent with the tissue connectivity of the tree and its rhizome, explaining the dual infection in the two types of tissues through systemic infection. Similarly, the detection of TRSV in root and fruit tissue of some trees in the pawpaw orchard in Maryland confirms a systemic infection. The recovery from symptoms in pawpaw tree is also consistent with the occurrence of TRSV and ToRSV, two nepoviruses for which initial infection causes severe systemic symptoms and infected plants recover later, as documented on experimental herbaceous plant hosts. The pawpaw is a delicious and nutritious native American fruit. A recent increased interest in pawpaw amongst groups of Indigenous Peoples, gardeners, and nontraditional fruit enthusiasts has driven up the demand for pawpaw fruits and trees. The propagation of clonal pawpaw rootstocks has been unsuccessful; therefore, nurseries currently graft cultivars onto rootstock derived from locally available seeds of diverse genetic origin. Alternatively, nurseries sell dormant or sprouted seeds.

Pawpaw orcharding is advertised as a business opportunity for small growers, particularly as food processors develop recipes to turn mature pawpaw fruit into value-added products. Beyond North America, pawpaw plantings are documented in Romania, Italy, Ukraine, Slovakia, Austria, Georgia, Russia, Japan, and Korea. Some of these plantings are derived from sprouted seeds, whereas others are planted with grafted cuttings. There is no cure for TRSV and ToRSV once trees are infected in the orchard. Therefore, based on the expansion of pawpaw orchards in the United States and worldwide, a careful selection of clean pawpaw seeds and propagation material is critical for producing clean grafted cultivars and preventing the introduction of viruses, such as TRSV and ToRSV, in newly established orchards. Such simple measures are salient for pawpaw because this deciduous fruit tree is considered vulnerable or endangered in several regions of the United States, and there is a strong desire to save this indigenous fruit tree species by Indigenous Peoples in New York.Six to eight pawpaw leaves from the mid-point of branches were collected in October 2021 from symptomatic and asymptomatic pawpaw trees, as well as from symptomatic pawpaw saplings growing underneath the trees in the experimental orchard managed by Cornell University. Leaf samples were similarly collected from two asymptomatic pawpaw trees located on the main campus of Cornell University in Ithaca, New York, which is approximately 12 km away from the experimental orchard.

These samples were selected as negative controls in HTS work to avoid confounding effects of possible virus infections in asymptomatic trees from the experimental orchard. Additional leaf samples were collected from the same pawpaw trees, and eight additional symptomatic and two asymptomatic trees in the experimental orchard in May 2022 for validation work. Finally, flowers were collected from those 12 selected trees in the experimental pawpaw orchard for virus testing. Roots, flowers, small fruits, and symptomatic leaves were also collected from two grafted ‘Shenandoah’ trees in a commercial pawpaw orchard in Westminster, Maryland in June 2022 for virus testing.The goal of all living organisms, as well as plants, is to produce offspring for the next generation. One way plants produce offspring is through making fruits and seeds, the product of successful pollination. Pollination is the process of transferring pollen from the anthers of a flower to the stigma of the same flower or of another one of the same species. Pollen grains of the correct type that land on the stigma germinate and grow a pollen tube down through the style and into the ovules . This process results in fertilization, which, in flowers, leads to the production of fruits and seeds. Seeds contain embryos that become the next generation of plants. Most flowering plants require pollination and have developed a variety of methods for pollen transfer, such as wind, water, biotic agents , and self-pollination. Some flowering plants also reproduce by vegetative means. The relationships that exist between flowering plants and pollinators are not casual, as many plants and pollinators have coevolved over long periods of time to efficiently exchange services. Pollination of flowers by pollinators is the unintended outcome of their activity on the flower. As pollinators visit flowers to sip nectar or gather pollen for their brood, pollen grains are dispersed among plants of the same species, allowing plants to reproduce. Plants have evolved to reward pollinators for visiting their flowers by providing sweet nectar or pollen. The fates of pollinators and flowering plants are thus inextricably bound.Bees are the most important biotic agent for the pollination of agricultural crops, horticultural plants, and wildflowers . People are often most familiar with the introduced European honey bee , which was brought to the eastern United States 400 years ago; it arrived in California around 1850. The honey bee is just one species of bee in this incredibly diverse group of pollinators. Approximately 4,000 species of bees exist in the United States, with 1,600 of those residing in California . About 20,000 species have been recorded worldwide . Native bee species come in a variety of shapes, colors, sizes, and lifestyles that enable them to pollinate a diversity of plant species .Hummingbirds Hummingbirds are the most prominent pollinating birds in North America. These birds have long beaks and tongues that can reach deep into flowers to harvest sugary nectar. When a hummingbird stops in for a sip of nectar, pollen can be transported from the flowers to the beak, feathers, or both. Hummingbirds forage on insects and spiders for their protein source . Butterflies These gorgeous, often colorful, daytime-flying insects have long been purposely lured to flowers by gardeners. Butterfly larvae, or caterpillars, require specific plants to feed on, 25 liter plant pot though the adults can use nectar from many plants.

While adult butterflies are not as efficient pollinators as are bees, they do transfer pollen that sticks to their legs as they flit from flower to flower. Their stunning looks have made them attractions at many botanical gardens and zoos, where butterfly houses and gardens stock their favorite flowers for nectar resources .Moths Moths are mostly evening fliers attracted to many late afternoon, night, and early morning sweet-smelling flowers for their nectar. Moths tend to have hairier and stouter bodies and are generally less colorful than butterflies. They are easy to differentiate from butterflies if you look at their antennae: moths do not have a swelling at the end of their antennae whereas butterflies do. Bats Bats are nocturnal pollinators that play an important role in the pollination of agaves and cacti in the Southwest, as well as many tropical and subtropical plants such as bananas, avocados, and cashews . Bats are usually found visiting light-colored flowers that open at night and often produce copious amounts of pollen and nectar. For example, the Mexican long-nosed bat is a species that has evolved a special head and tongue to allow access to both pollen and nectar from flowers of century plants . Flies Flies are not typically thought of as pollinators; however, research suggests that many flies, such as hover flies and bee flies , are generalist pollinators. Generalist pollinators are important inhabitants of gardens because they visit wide varieties of plants, searching mostly for nectar and in some cases pollen . Beetles Up to 28,000 known beetle species exist in the United States; however, as a group, few species are recognized as pollinators . While beetles are not efficient pollinators, many visit flowers to sip nectar or feed on the flower parts. Their activities may result in pollination. A few plants, such as magnolias, are typically pollinated by beetles.More than 75 percent of flowering plants worldwide rely on animals for pollination; thus ecosystems around the planet are dependent on their services . Pollinators are responsible for the majority of beautiful flowers surrounding us and many of the diverse food plants we eat. In the United States over one-third of the food we eat is dependent on one type of pollinator: bees . If you enjoy watermelon, kiwi, squash, almonds, cherries, peaches, blueberries, apples, and many other fruits, nuts, and vegetables, then you should be concerned about protecting our valuable pollinators. The importance of conserving a diversity of pollinators has become more apparent as the introduced European honey bee population has declined due to colony collapse disorder . Unique to honey bee colonies, CCD causes worker bees to suddenly and mysteriously disappear. Single hive losses ranging from 30 to 100 percent have been reported by beekeepers in both North America and Europe . Honey bees are relatively inexpensive, and the industry standard when experiencing large hive losses is to order additional hives. A growing concern, however, is that if hive losses continue to increase, demand for honey bees will become too great to sustain. What will not decrease is flowering plants’ need for successful pollination from their associated pollinator. While scientists still do not know the exact cause of CCD, they do know that managed honey bees are subjected to a number of stressors, such as pesticide poisoning, low food-source variety, and long transports between various climate regions. These stressors, in addition to predatory mites and pathogens, contribute significantly to honey bee mortality .Properly planned sites in urban areas can provide floral and nesting resources for pollinators as wild land areas decrease. Urban habitat gardens, if planned correctly with appropriate resources, can support pollinator populations . A habitat garden provides wildlife with known resources for survival: food , water , shelter , and a place to raise young . In addition, habitat gardens may see an increase of fruits, nuts, vegetables, and showy flowers . Maximize your yard’s pollinator potential by considering the following recommendations.Seasonal sequence of flowers Plan your garden with a variety of plant types, defined as plant species, subspecies, varieties, cultivars, and hybrids that will bloom from late winter or early spring to late summer or early fall . From 14 years of survey research by the Urban Bee Lab in urban California gardens, it has been determined that a minimum of 20 plant types is necessary to cover the entire bee and flowering seasons from midwinter to the end of October. Selecting plant species with a staggered bloom sequence ensures food for each pollinator’s unique season. As with plants, each pollinator species has its own season of adult activity .