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opencc-zeroJan 2022View details →

Effects of embryo energy, egg size and larval food supply on the development of asteroid echinoderms

Organisms have limited resources available to invest in reproduction, causing a tradeoff between the number and size of offspring. One consequence of this tradeoff is the evolution of disparate egg sizes and, by extension, developmental modes. In particular, echinoid echinoderms (sea urchins and sand dollars) have been widely used to experimentally manipulate how changes in egg size affect development. Here we test the generality of the echinoid results by 1) using laser ablations of blastomeres to experimentally reduce embryo energy in the asteroid echinoderms (sea stars), Pisaster ochraceus and Asterias forbesi and 2) comparing naturally produced, variably-sized eggs (1.7 fold volume difference between large and small eggs) in A. forbesi. In P. ochraceus and A. forbesi there were no significant differences between juveniles from both experimentally reduced embryos and naturally produced eggs of variable size. However, in both embryo reduction and egg size variation experiments, simultaneous reductions in larval food had a significant and large effect on larval and juvenile development. These results indicate that 1) food levels are more important than embryo energy or egg size in determining larval and juvenile quality in sea stars and 2) the relative importance of embryo energy or egg size to fundamental life history parameters (time-to and size-at metamorphosis), does not appear to be consistent within echinoderms.

opencc-by-4.0Jan 2022View details →

Complete Genome Sequence of an Aeromonas rivuli Strain Isolated from Ready-to-Eat Food - Data Files

This dataset contains input and intermediate files of the bcgTree analysis described in the Schwartz et al. MRA manuscript entitled “Complete Genome Sequence of an Aeromonas rivuli Strain Isolated from Ready-to-Eat Food”. <table> <tbody> <tr> <td> File name </td> <td> Description </td> </tr> <tr> <td> ‘Aeromonadaceae identifier’.fa </td> <td> Amino acid FASTA file of the translated CDS sequences of a strain X (bcgTree input file) </td> </tr> <tr> <td> full_alignment.concat.fa </td> <td> Alignment of the concatenated amino acid sequences of 107 single-copy core genes that is used for phylogenetic tree calculation in bcgTree (bcgTree intermediate file) </td> </tr> </tbody> </table>   In the bcgTree files, the Aeromonadaceae sequences were named/abbreviated as follows: <table> <tbody> <tr> <td> Sequence name in the bcgTree file </td> <td> Description </td> </tr> <tr> <td> AAZUK01-1 </td> <td> Tolumonas lignilytica BRL6-1 </td> </tr> <tr> <td> Aeromonas-caviae </td> <td> Aeromonas caviae NCTC 12244 </td> </tr> <tr> <td> Aeromonas-dhakensis </td> <td> Aeromonas dhakensis CIP 107500 </td> </tr> <tr> <td> Aeromonas-hydrophila </td> <td> Aeromonas hydrophila ATCC 7966 </td> </tr> <tr> <td> Aeromonas-rivuli </td> <td> Aeromonas rivuli DSM 22539 </td> </tr> <tr> <td> Aeromonas-rivuli-20-VB00005 </td> <td> Aeromonas rivuli 20-VB00005 </td> </tr> <tr> <td> Aeromonas-veronii </td> <td> Aeromonas veronii CECT 4257 </td> </tr> <tr> <td> CP001616-1 </td> <td> Tolumonas auensis DSM 9187 </td> </tr> <tr> <td> JACHGR01-1 </td> <td> Tolumonas osonensis DSM 22975 </td> </tr> </tbody> </table>

opencc-by-4.0Jan 2022View details →

The effects of integrated food and bioenergy cropping systems on crop yields, soil health, and biomass quality: the EU and Brazilian experience

Data Set This multiyear and multi-location study provides new insights on the integration of dedicated legume crops within conventional EU (wheat-maize) and Brazilian (sugarcane) farming systems so to meet the forecasted increasing feedstock demands for the production of renewable transport biofuels without negatively affecting food production nor soil fertility. Sunn hemp demonstrated to be a suitable leguminous fiber feedstock to be grown in extended crop rotations. Integrating sunn hemp within the conventional systems in EU did not have negative effects on food yields, while feedstock availability increased up to 2.0 times. In Brazil, sugarcane stalks yield increased up to 15 Mg ha-1.

opencc-zeroFeb 2022View details →

Carry-over effects of larval food stress on adult energetics and life history in a nectar-feeding butterfly

Stressful juvenile developmental conditions can affect performance and fitness later in life. In holometabolous insects such as butterflies, development under stressful conditions may lead to smaller adult size, lower reproductive output and shorter lifespan. However, how larval developmental stress affects energy intake and expenditure in adult individuals is poorly understood. We subjected last-instar larvae of Speyeria mormonia Edwards (Lepidoptera: Nymphalidae) to periodic dietary restriction (DR) to examine the allocation of energy and nutrients among different life-history processes. We measured adult food intake, resting metabolic rate (RMR), metabolic flight capacity, lifespan, and reproductive output. Consistent with pressure to disperse from a poor environment while maintaining offspring number, we predicted that stressed individuals would have increased adult food intake and higher flight capacity. Adult body size was strongly reduced. Contrary to predictions, we found no compensatory adult feeding. Mass-adjusted flight metabolic rate was reduced, suggesting poor dispersal capacity. Larval DR did not affect adult lifespan, nor did the rate of metabolic senescence change. Larval DR did affect RMR, as stressed females had a steeper slope between RMR and body mass, which may reflect differences in physiological activity due to condition. Fecundity decreased less than predicted based on body mass. Instead of investing in flight capacity, females increased relative allocation to reproduction, which may partly buffer against poor environmental conditions. Understanding the interplay of energy acquisition and allocation to life history traits across the life cycle is vital for predicting responses to environmental change.

opencc-by-4.0Feb 2022View details →

Laboratory capability Survey - POPs in Food and Feed, CFSA

POPs analysis capabilities of  China National Centre for Food Safety Risk Assessment (CSFA)

opencc-by-4.0Feb 2022View details →

Laboratory capability Survey - POPs in Food and Feed, Irish State Laboratory

POPs analysis capabilities at the Irish State Laboratories

opencc-zeroFeb 2022View details →

Data from: Balancing food acquisition and predation risk drives demographic changes in snowshoe hare population cycles

Snowshoe hare cycles are one of the most prominent phenomena in ecology. Experimental studies point to predation as the dominant driving factor, but previous experiments combining food supplementation and predator removal produced unexplained multiplicative effects on density. We examined the potential interactive effects of food limitation and predation in causing hare cycles using an individual based food-supplementation experiment over-winter across three cycle phases that naturally varied in predation risk. Supplementation doubled over-winter survival with the largest effects occurring in the late increase phase. Although the proximate cause of mortality was predation, supplemented hares significantly decreased foraging time and selected for conifer habitat, potentially reducing their predation risk. Supplemented hares also lost less body mass which resulted in the production of larger leverets. Our results establish a mechanistic link between how foraging time, mass loss, and predation risk affect survival and reproduction, potentially driving demographic changes associated with hare cycles.

opencc-zeroFeb 2022View details →

A systematic review of long-term avian studies on phenological changes of birds and their food

Many organisms reproduce in seasonal environments, where selection on timing of reproduction is particularly strong as consumers need to synchronize reproduction with the peaked occurrence of their food. When a consumer species changes its phenology at a slower rate than its resources, this may induce a trophic mismatch, i.e. offspring growing up after the peak in food availability, potentially leading to reductions in growth and survival. However, there is large variation in the degree of trophic mismatches as well as in its effects on reproductive output. Here, we explore the potential causes for variation in the strength of trophic mismatches in published studies of birds. Specifically, we ask whether the changes in the degree of mismatch that have occurred over time can be explained by a bird's (1) breeding latitude, (2) migration distance, and/or (3) life-history traits. In particular, the script used contains the following analyses: (I) using linear mixed effect models we test whether the rate of change in food phenology, bird phenology and their difference (i.e. the rate of change in asynchrony) differed significantly from zero, (II) using linear mixed effect models we test whether the rate of change in asynchrony between birds and their food could be explained by breeding latitude, migratory behaviour and/or species life-history traits (body mass, clutch size and incubation duration). We found that none of these three factors explains changes in the degree of mismatch over time. Nevertheless, food phenology did advance faster at more northerly latitudes, while shifts in bird phenology did not show a trend with latitude. We argue that the lack of support in our results is attributable to the large variation in the metrics used to describe timing of food availability.

opencc-byMar 2022View details →

Is switchgrass good for carbon savings? Long-term results in marginal land Running title: Switchgrass SOC storage capacity in marginal land Walter Zegada-Lizarazu 1, Federica Zanetti 1, Nicola Di Virgilio 2, Andrea Monti 1 1Department of Agricultural and Food Sciences, University of Bologna, Viale G. Fanin 44 – 40127, Bologna, Italy; 2CNR, Institute for the BioEcononomy, National Research Council of Italy, Via P Gobetti 101, I-40129 Bologna, Italy

Growing switchgrass in marginal land can be a valuable option to mitigate the risk of agricultural land abandonment whilst storing a significant amount of soil C. It was found a significant increase in SOC in a 13-years period. A significant positive correlation was observed between the C derived from switchgrass and SOC gain (the estimated switchgrass derived C was 12.7 Mg C ha-1). The increased SOC along the field, however, was patchy, with the highest increments registered in the center of the field, while the lowest ones in the top and bottom of the hill.

opencc-zeroMar 2022View details →

Data from: Ancestral ecological regime shapes reaction to food limitation in the Least Killifish, Heterandria formosa

Populations with different densities often show genetically-based differences in life histories. The divergent life histories could be driven by several agents of selection, one of which is variation in per-capita food levels. Its relationship with population density is complex, as it depends on overall food availability, individual metabolic demand, and food-independent factors potentially affecting density, such as predation intensity. Here we present a case study of two populations of a small live-bearing freshwater fish, one characterised by high density, low predation risk, low overall food availability, and presumably low per-capita food levels, and the other by low density, high predation risk, high overall food availability, and presumably high per-capita food levels. Using a laboratory experiment we examined whether fish from these populations respond differently to food limitation, and whether size at birth, a key trait with respect to density variation in this species, is associated with any such differential responses. While at the lower food level growth was slower, body size smaller, maturation delayed and survival reduced in both populations, these fitness costs were smaller in fish from the high-density population. At low food, only 15% of high-density fish died, compared to 75% of low-density fish. This difference was much smaller at high food (0% vs. 15% mortality). The increased survival of high-density fish may, at least partly, be due to their larger size at birth. Moreover, being larger at birth enabled fish to mature relatively early even at the lower food level. We demonstrate that sensitivities to food limitation differ between study populations, consistent with selection for a greater ability to tolerate low per-capita food availability in the high-density population. While we cannot preclude other agents of selection from operating in these populations simultaneously, our results suggest that variation in per-capita food levels is one of those agents.

opencc-by-4.0Mar 2022View details →

Supplementary data for the article "A data-driven simulation of the trophallactic network and intranidal food flow dissemination in ants."

Supplementary figures, tables and raw data for the article " "A data-driven simulation of the trophallactic network and intranidal food flow dissemination in ants." Food sharing can occur in both social and non-social species but is crucial in eusocial species in which only some group members collect food. This food collection but also intranidal food distribution through trophallactic (i.e. mouth-to-mouth) exchanges are fundamental issues in eusocial insects. However, the behavioural rules underlying the regulation and the dynamics of food intake and the resulting networks of exchanges are poorly understood. In this study, we provide new insights into the behavioural rules underlying the structure of trophallactic networks and food dissemination dynamics within the colony. We build a simple data-driven model that implements interindividual variability and division of labour to investigate the processes of food accumulation/dissemination inside the nest, both at the individual and collective levels. We also test the alternative hypotheses (no variability and no division of labour). Division of labour with inter-individual variability predicts contrary to other models the food dynamics and exchange networks. We establish the links between the interindividual heterogeneity of the trophallactic behaviours, the food flow dynamics and network of trophallactic events. Despite the relative simplicity of the model rules, efficient trophallactic networks may emerge as the ones observed in ants leading to better understanding of evolution of such societies.

Honey bee hive covers reduce food consumption and colony mortality during overwintering

Beekeepers regularly employ management practices to mitigate losses during the winter, often considered the most difficult time during a colony life cycle. Management recommendations involving covering or wrapping hives in insulation during winter have a long history; over 100 years ago, most recommendations for overwintering in cold climates involved heavy insulation wraps or moving hives indoors. These recommendations began to change in the mid-20th century, but hive covers are still considered useful and are described in contemporary beekeeping manuals and cooperative extension materials. However, most of the data supporting their use is published primarily in non-peer reviewed trade journals and was collected >40 years ago. In this time, the beekeeping environment has changed substantially, with new pressures from pathogens, agrochemicals, and land use changes. Here, we provide an update to the historical literature, reporting a randomized experiment testing the effectiveness of a common honey bee hive cover system across eight apiaries in central Illinois, USA, a temperate region dominated by conventional annual agriculture. We found that, when other recommended overwintering preparations are performed, covered colonies consumed less food stores and survived better than uncovered controls (22.5% higher survival). This study highlights the value of hive covers, even in an area not subject to extremely cold winter conditions, and these data can aid the production of evidence-based extension recommendations for beekeepers.

Metabolic depression in sea urchin barrens associated with food deprivation

The proliferation of sea urchins can decimate macroalgal forests in coastal ecosystems, leading to persistent barren seascapes. While kelp forests are among the most productive ecosystems on the planet, productivity in these urchin barrens is dramatically reduced. Moreover, urchins inhabiting these food-depauperate barrens face starvation and many survive in these barrens for years or decades. Urchins in barrens can persist by eating food subsidies from drift algae, pelagic salps, tubeworms, as well as encrusting and filamentous algae, microbial mats, and slow-growing species resistant to herbivory. Despite both food from endogenous production and exogenous subsidies, many urchins in barrens likely experience prolonged food deprivation. This resource limitation may create a trade-off between reproduction and survival; for example, fecundity of purple sea urchins (Strongylocentrotus purpuratus) is 99.9% lower in barrens. Despite food constraints, red sea urchins (Mesocentrotus franciscanus), the dominant urchin species at our study sites, can live in excess of 100 years and barrens in Haida Gwaii, British Columbia (BC), Canada, have persisted for at least 143 years. While these phenomena are widespread and well documented, the bioenergetic adaptations that allow urchins to persist in these food-depauperate barrens remain poorly understood. To quantify habitat-specific differences in metabolic rates and energy reserves (as measured by gonadal mass), we conducted respirometry on and measured gonadal mass in M. franciscanus at three locations in BC inside and outside of adjacent kelp forest and barrens habitat. Here we demonstrate that M. franciscanus in barrens versus kelp forests have substantially lower energy reserves and, importantly, also exhibit dramatic reductions in size-specific resting metabolic rates (RMR), even after standardizing by metabolically active body mass. On average, gonadal mass was 44.6% lower and RMR scaled to metabolically active body mass was 40% lower in barrens urchins than in kelp forest urchins. Such a shift in metabolic rate may provide a mechanism that facilitates barren state stability over long time scales as M. franciscanus can lower energetic demands while they wait for small pulses of food, scrape by on low-productivity resources, and suppress recruitment of macroalgae for months, years, or decades.

Impacts on food web properties of island invertebrate communities vary between different human land uses

Human land use is of growing concern for island ecosystems. Besides direct impacts on biodiversity, land uses can alter the functioning and structure of ecosystems. Central to this are impacts on food webs. The release of additional nutrients from human origin, habitat homogenization, or environmental filtering due to human land use can change the diet of individual consumer species (i.e., their trophic niches) and the distribution and overlap of trophic niches within a food web. However, it remains largely unclear whether the effects on food web properties vary between the different and predominant human land uses present on islands. Here, we investigated the impact of two dominant human land uses on small oceanic islands (i.e., urban and tourism development) and tested if and how different land uses on islands affect food web structure. To disentangle human land uses, we investigated islands, which were either privately owned by a tourist facility (i.e., exclusively tourism land use) or experienced urban development from the local population (i.e., urban land use), or remained uninhabited, serving as reference sites free of direct land use. Using stable isotope analysis, we show that isotope signature, trophic (isotopic) niches, and overall food web properties of the investigated island invertebrate communities were significantly changed under both land use regimes. While trophic diversity was reduced and trophic niche widths increased under tourism land use, the investigated food webs showed reduced trophic diversity at the food web base and a more uneven trophic niche distribution under urban land use. In summary, these findings show that different human land uses can have contrasting impacts on oceanic island food webs. As oceanic islands experience rapidly growing human land conversion, our results indicate that they may also face increasing yet unpredictable long-term changes in food web dynamics.

opencc-by-4.0Apr 2022View details →

Potential and limits of cultivation of brackish and freshwater populations of tubular morphotypes of Ulva (Ulvophyceae) in food industry or biotechnologies -supplementary material

Supplementary material for diploma thesis: Potential and limits of cultivation of brackish and freshwater populations of tubular morphotypes of Ulva (Ulvophyceae) in food industry or biotechnologies.

Even short-term revegetation complicates soil food webs and strengths their links with ecosystem functions

Degradation of dryland ecosystems is a worldwide problem caused by climate change and human activities. To restore these degraded ecosystems, governments have implemented projects that often include revegetation, but we still lack an understanding of how soil food webs and ecosystem functions are affected by revegetation. By conducting a large-scale revegetation experiment under two degradation intensities (low and high) on the Inner Mongolian degraded grassland, we tested the effects of revegetation on primary producers (plants), key components of soil food webs (bacteria, fungi, and nematodes), and ecosystem functions (soil C and N mineralization). After 4 years, revegetation greatly increased the biomass of plants and soil bacteria and fungi but had less effects on soil nematode functional groups. Revegetation increased vegetation and bacterial diversities and soil C and N mineralization rates, altered the structures of vegetation and soil microbial communities, but did not affect fungal or nematode diversity. The stronger effects of revegetation on plants, soil bacteria, soil fungi, and soil nematodes in plots with low degradation intensity than in plots with high degradation intensity indicated that future revegetation efforts should consider the degree of degradation. Revegetation also increased the interactions among plants, soil food webs, and ecosystem functions, indicating that the revegetation-induced changes in soil food webs could facilitate the recovery of soil nutrients and vegetation productivity in degraded grasslands. Synthesis and applications. Overall, the effects of revegetation were stronger on plants (primary producers) and soil microorganisms (intermediate trophic levels) than on soil nematodes (higher trophic levels), and even short-term revegetation increased the complexity of soil food webs and strengthened their relationships with soil functions in degraded grasslands. These results highlight the effects of restoration on multiple trophic levels in degraded drylands, and suggest that some aspects of plant-soil interactions in global drylands could be rapidly improved by appropriate restoration.

opencc-zeroMay 2022View details →

Phylogenetic relatedness of food plants reveals highest insect herbivore specialization at intermediate temperatures along a broad climatic gradient

Phytophagous insects differ in their degree of specialisation, biased by resource availability. The composition and richness of herbivore and plant assemblages change along climatic gradients, but knowledge about associated shifts in specialisation is scarce and lacks controlling for abundance and phylogeny of interaction partners. Thus, we aimed to test whether the specialisation of herbivores in insect- plant – interaction networks decreases towards cold habitats as predicted by the 'altitude niche-breadth hypothesis' to forecast possible consequences of interaction rewiring under climate change. We used a non-invasive, standardized metabarcoding approach to reconstruct dietary relationships of Orthoptera species as a major insect herbivore taxon along a broad temperature gradient (~12 °C) in southern Germany. Based on orthopteran surveys, direct feeding observations in field, collection of faecal pellets from > 3,000 individuals of 54 species, and parallel vegetation surveys on 41 grassland sites, we quantified plant resource availability and its use by herbivores. Faecal samples were pooled for each species per site.

opencc-zeroDec 2020View details →

Transfer efficiency of carbon, nutrients, and PUFAs in planktonic food webs under different environmental conditions

We investigated the transfer of essential substances (carbon, nutrients, and polyunsaturated fatty acids) through plankton communities in 30 Polish lakes with different trophic status in the middle of summer. The results of our study revealed that different essential substances were transferred from phytoplankton to zooplankton with varying efficiencies. The average TTE of C, N, P, and the sum of ω-3 PUFA were 6.55%, 9.82%, 15.82%, 20.90%, respectively. Our results also show a large mismatch between the elemental and biochemical compositions of zooplankton and their food during the peak of the summer stagnation, which may further promote the accumulation of essential substances. There were also large differences in TTEs between trophic conditions, with the highest efficiencies in oligotrophic lakes and the lowest in dystrophic and eutrophic lakes. Therefore, our study indicates that disturbances like eutrophication and dystrophication similarly decrease the TTE of essential substances between phytoplankton and zooplankton in freshwater food webs.

opencc-zeroMay 2022View details →

Food for thought: Barro Colorado Island frugivore home range summaries

This dataset consists of home-range area summaries of four species of frugivores on Barro Colorado Island, Panama, including 12 kinkajou (Potos flavus), 16 white-nosed coati (Nasua narica), 8 white-faced capuchin monkey (Cebus capucinus), and 8 spider monkey (Ateles geoffroyi). Summaries include effective sample sizes (DOF) as well as parameter estimates (in hectares) including upper and lower confidence intervals. Metadata for each individual are provided including their indivdual ID and species ID. The summaries of the autocorrelated kernel density estimates include additional metadata regarding the sex, weight, and sampling year of each individual.