Consistent predator-prey biomass scaling in complex food webs

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Авг. 25, 2022

Abstract The ratio of predator-to-prey biomass is a key element trophic structure that typically investigated from food chain perspective, ignoring channels energy transfer (e.g. omnivory) may govern community structure. Here, we address this shortcoming by characterising the 141 freshwater, marine and terrestrial webs, spanning broad gradient in biomass. We test whether sub-linear scaling between predator prey (a potential signal density-dependent processes) emerges within ecosystem types across levels biological organisation. find consistent, pattern whereby scales with total their near ¾-power exponent webs - i.e. more supports proportionally less Across similar combined all web. These general patterns are compatible systematic form density dependence holds among complex feeding interactions organization, irrespective type.

Язык: Английский

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Body size and food–web interactions mediate species range shifts under warming

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2022, Номер 289(1972)

Опубликована: Апрель 13, 2022

Species ranges are shifting in response to climate change, but most predictions disregard food–web interactions and, particular, if and how such change through time. Predator–prey could speed up species range shifts enemy release or create lags biotic resistance. Here, we developed a spatially explicit model of interacting species, each with thermal niche embedded size-structured across temperature gradient that was then exposed warming. We also created counterfactual single models contrast highlight the effect trophic on shifts. found dynamic hampered 450 simulated food–webs 200 over years All experiencing shifted more slowly than single-species would predict. In addition, trailing edges larger bodied especially because ecological subsidies from small prey. Trophic reduced numbers locally novel productive thus maintaining historical community compositions for longer. Current forecasts ignoring allometry may overestimate species' tendency track change.

Язык: Английский

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Identifying and explaining resilience in ecological networks

Ecology Letters, Год журнала: 2024, Номер 27(8)

Опубликована: Авг. 1, 2024

Abstract Resilient ecological systems are more likely to persist and function in the Anthropocene. Current methods for estimating an ecosystem's resilience rely on accurately parameterized ecosystem models, which is a significant empirical challenge. In this paper, we adapt tools from biochemical kinetics identify networks that exhibit ‘structural resilience’, strong form of solely property network structure independent model parameters. We undertake exhaustive search structural across all three‐species networks, under generalized Lotka‐Volterra modelling framework. Out 20,000 possible structures, approximately 2% display resilience. The properties these provide important insights into mechanisms could promote ecosystems, new theoretical avenues qualitative approaches foundation identifying robust forms large, realistic networks.

Язык: Английский

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Ubiquity of inverted ’gelatinous’ ecosystem pyramids in the global ocean

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Фев. 12, 2024

Summary paragraph Plankton are essential in marine ecosystems. However, our knowledge of overall community structure is sparse due to inconsistent sampling across their very large organismal size range. Here we use diverse imaging methods establish complete plankton inventories organisms spanning five orders magnitude size. and trophic variation validate a long-held theoretical link between organism size-spectra ecosystem structures. We found that predator/grazer biomass biovolume unexpectedly exceed primary producers at most (55%) locations, likely better quantification gelatinous organisms. Bottom- heavy ecosystems (the norm on land) appear be rare the ocean. Collectively, represent 30% total (8-9% carbon) communities from tropical polar Communities can split into three extreme typologies: diatom/copepod-dominated eutrophic blooms, rhizarian/chaetognath-dominated oligotrophic oceans, gelatinous-dominated elsewhere. While taxonomic composition changes with latitude, functional structures mostly depend amount prey available for each level. Given future projections oligotrophication ecosystems, findings suggest rhizarian will increasingly dominate apex position planktonic leading significant ocean’s carbon cycle.

Язык: Английский

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Thermal mismatches in biological rates determine trophic control and biomass distribution under warming

Global Change Biology, Год журнала: 2020, Номер 27(2), С. 257 - 269

Опубликована: Окт. 21, 2020

Abstract Temperature has numerous effects on the structure and dynamics of ecological communities. Yet, there is no general trend or consensus magnitude directions these effects. To fill this gap, we propose a mechanistic framework based key biological rates that predicts how temperature influences biomass distribution trophic control in food webs. We show predictions arise from thermal mismatches between across levels. couple our theory with experimental data for wide range species find warming should lead to top‐heavier terrestrial chains stronger top‐down aquatic environments. then derive herbivory validate them stream grazers. Our study provides explanation consumer–resource systems which crucial better understand biogeography consequences global dynamics.

Язык: Английский

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Network analysis suggests changes in food web stability produced by bottom trawl fishery in Patagonia

Scientific Reports, Год журнала: 2022, Номер 12(1)

Опубликована: Июнь 27, 2022

Demersal fisheries are one of the top anthropic stressors in marine environments. In long term, some species more vulnerable to fishery impacts than others, which can lead permanent changes on food web. The trophic relationships between predator and prey constitute web it represents a network energy channels an ecosystem. turn, structure influences ecosystem diversity stability. first aim this study was describe for time San Jorge Gulf (Patagonia Argentina) with high resolution, i.e. level when information is available. subject intense thus our second analyse without evaluate if bottom-trawl industrial altered We used several metrics like: mean level, omnivory, modularity quasi-sign included these because they related stability be evaluated using diets that weight links predators prey. presented 165 organized almost five levels. inclusion node adds 69 new links. All weighted unweighted showed differences two networks, reflecting decrease system. Thus, results suggested probable change state observed abundances since established, could represent predicted by analysis. Our suggests webs human activity ecosystems.

Язык: Английский

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Subsidy type and quality determine direction and strength of trophic cascades in arthropod food webs in agroecosystems

Journal of Applied Ecology, Год журнала: 2019, Номер 56(8), С. 1982 - 1991

Опубликована: Май 31, 2019

Abstract The subsidy hypothesis states that communities receiving nutrient subsidies will demonstrate top‐down trophic cascades where predators indirectly increase plant biomass. This has been both confirmed and refuted, which might depend on whether the mainly targeted or detrital food web compartment, quality. is particularly poorly understood for terrestrial such as heavily subsidized agroecosystems. Using cages covering 4 m 2 of ground in a long‐term agricultural fertilization experiment, we tested targeting soil mesofauna compartment with organic fertilizers, plants mineral fertilizer, impacted direction strength an arthropod–plant web. We expected controls generalist arthropod (spiders, rove beetles) aphid densities to be stronger organically fertilized plots due enhanced alternative prey availability soil. Bottom‐up control from barley quality aphids was anticipated treatments. examined how (decomposability) governed by comparing treatments labile (manure) recalcitrant (hay) matter. Top‐down forces dominated webs subsidies, while bottom‐up under fertilization. A high‐quality, easily degradable propagated faster through chain, leading cascade having positive effect biomass but not treatment. Synthesis applications . Management soils bolster mesofauna, example adding potential biological naturally occurring predators. Our research demonstrates can manure treatment presence level comparable fertilizer.

Язык: Английский

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Cascading effects of moth outbreaks on subarctic soil food webs

Scientific Reports, Год журнала: 2021, Номер 11(1)

Опубликована: Июль 23, 2021

Abstract The increasing severity and frequency of natural disturbances requires a better understanding their effects on all compartments biodiversity. In Northern Fennoscandia, recent large-scale moth outbreaks have led to an abrupt change in plant communities from birch forests dominated by dwarf shrubs grass-dominated systems. However, the indirect belowground compartment remained unclear. Here, we combined eDNA surveys multiple trophic groups with network analyses demonstrate that defoliation has far-reaching consequences soil food webs. Following this disturbance, diversity relative abundance certain declined (e.g., ectomycorrhizal fungi), while many others expanded bacterivores omnivores) making webs more diverse structurally different. Overall, direct increased at different levels. Our results highlight holistic view ecosystems improves our cascading major

Язык: Английский

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Understanding trophic structure variation in fish assemblages of subtropical shallow lakes: Combined effects of ecosystem size, productivity, and disturbance

Ecological Indicators, Год журнала: 2021, Номер 129, С. 107924 - 107924

Опубликована: Июнь 28, 2021

Global environmental change has altered biotic interactions in ecosystems. Trophic structure is a major characteristic of ecosystems, and understanding the factors determining trophic thus important for predicting response ecological dynamics ecosystem services to future change. Different kinds drivers, including size, productivity, disturbance, have been proposed explain variation various Much remains unknown about how these drivers operate its underlying mechanisms, particularly shallow lakes. Here, we evaluated relative importance productivity disturbance influencing fish assemblages 30 subtropical We determined that (1) had no effect on food chain length; (2) mean level increased with increasing size contributing most explaining variance level; (3) alone or combined, affected proportion species at specific levels. These results indicate potential systematic discrepancies among different systems highlight focusing length may not be sufficient reflecting status. Thus, changes trophic-level guilds must considered lake management practices.

Язык: Английский

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Resource limitation determines realized thermal performance of consumers in trophodynamic models

Ecology Letters, Год журнала: 2022, Номер 25(10), С. 2142 - 2155

Опубликована: Авг. 27, 2022

Recent work has demonstrated that changes in resource availability can alter a consumer's thermal performance curve (TPC). When resources decline, the optimal temperature and breadth of also leading to greater risk warming than predicted by static TPCs. We investigate effect on coupled consumer-resource dynamics, focusing potential for consumer TPC extinction risk. Coupling dynamics generally reduces decline exacerbate effects via due reduction top-down control when consumers near limits their curve. However, if are more sensitive warming, TPCs be reshaped declining resources, increased Our elucidates role bottom-up regulation determining extent which density

Язык: Английский

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