Improving Marine Ecosystem Models with Biochemical Tracers

Annual Review of Marine Science, Год журнала: 2018, Номер 10(1), С. 199 - 228

Опубликована: Янв. 3, 2018

Empirical data on food web dynamics and predator-prey interactions underpin ecosystem models, which are increasingly used to support strategic management of marine resources. These have traditionally derived from stomach content analysis, but new complementary forms ecological available biochemical tracer techniques. Extensive opportunities exist improve the empirical robustness models through incorporation indices, an area that is rapidly expanding because advances in analytical developments sophisticated statistical Here, we explore trophic information required by model frameworks (species, individual, size based) match them most commonly tracers (bulk tissue compound-specific stable isotopes, fatty acids, trace elements). Key quantitative parameters include estimates diet composition, niche width, position. Biochemical also provide powerful insight into spatial temporal variability structure characterization dominant basal microbial groups. A major challenge incorporating scale type mismatches, can be overcome with greater knowledge exchange numerical approaches transform, integrate, visualize data.

Язык: Английский

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Resolving Food-Web Structure

Annual Review of Ecology Evolution and Systematics, Год журнала: 2020, Номер 51(1), С. 55 - 80

Опубликована: Июль 31, 2020

Food webs are a major focus and organizing theme of ecology, but the data used to assemble them deficient. Early debates over food-web focused on taxonomic resolution completeness, lack which had produced spurious inferences. Recent widely believed be much better extensively in theoretical meta-analytic research network ecology. Confidence these rests assumptions ( a) that empiricists correctly identified consumers their foods b) sampling methods were adequate detect near-comprehensive fraction trophic interactions between species. Abundant evidence indicates often invalid, suggesting most topological may remain unreliable for inferences about structure underlying ecological evolutionary processes. Morphologically cryptic species ubiquitous across taxa regions, many routinely evade detection by conventional methods. Molecular have diagnosed severity problems necessary part cure.

Язык: Английский

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Meta‐analysis and critical review of trophic discrimination factors (Δ¹³C and Δ¹⁵N): Importance of tissue, trophic level and diet source

Functional Ecology, Год журнала: 2023, Номер 37(9), С. 2535 - 2548

Опубликована: Июль 18, 2023

Abstract Robustly quantifying dietary resource use and trophic position using stable isotopes requires accurate discrimination factors (TDF; Δ 13 C 15 N for carbon nitrogen, respectively), defined as the isotopic difference between consumer diet. Early TDF studies converged on values of around 1.0‰ 3.4‰ but more recent work indicates that may be nuanced, depending taxa, tissues, level diets. Yet, relative importance these remains unclear. Focusing vertebrates (birds, fish, herptiles mammals), we conducted a literature review 279 estimated used Bayesian framework to determine how tissue type, diet source influence variation in N. Additionally, reviewed 358 ecology if accounted during their selection process. For C, showed consistent patterns among types (likely influenced by amino acid composition) levels sources result protein content metabolic routing). Comparatively, N, considerable levels, likely due differences synthesis physiological capabilities. Overall, ranged from −5.1‰ 9.1‰ −3.3‰ 9.7‰, underscoring are not universally appropriate. Moreover, both varied than 9‰ within single species demonstrating same, or similar, appropriate considered. Despite values, most did account it. Further, fish relied failed source. To aid ecologists assessments vertebrates, our meta‐analysis model taxon‐specific estimates (mean ± SD) each combination. These refined should improve ecological isotopes. Read free Plain Language Summary this article Journal blog.

Язык: Английский

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The power and pitfalls of amino acid carbon stable isotopes for tracing origin and use of basal resources in food webs

Ecological Monographs, Год журнала: 2025, Номер 95(1)

Опубликована: Янв. 22, 2025

Abstract Natural and anthropogenic stressors alter the composition, biomass, nutritional quality of primary producers microorganisms, basal organisms that synthesize biomolecules essential for metazoan growth survival (i.e., resources). Traditional biomarkers have provided valuable insight into spatiotemporal dynamics resource use, but lack specificity in identifying multiple organisms, can be confounded by environmental physiological processes, do not always preserve tissues over long timescales. Carbon stable isotope ratios amino acids (δ 13 C‐EAA) show remarkable promise distinguishing clades with unique δ C‐EAA fingerprints are independent trophic processing variability, providing unparalleled potential their application. Understanding biochemical processes underpin C‐AA data is crucial, however, holistic robust inferences ecological applications. This comprehensive methodological review, first time, conceptualizes these mechanistic underpinnings drive among incorporates C values non‐essential generally overlooked studies, despite gain metabolic information. We conduct meta‐analyses published to test hypothesized AA‐specific fractionations organism clades, demonstrating phenylalanine separates vascular plant fingerprints, which strongly covaries phylogeny. further explore utility AAs separating dietary protein sources archaeological humans, showing differences information contained within different NEAAs. By scrutinizing many methodologies applied field, we highlight absence standardized analytical protocols, particularly sample pretreatments leading biases, inappropriate use statistical methods, reliance on unsuitable training data. To unlock full provide in‐depth explanations knowledge gaps, pitfalls, optimal practices this complex powerful approach assessing ecosystem change across scales.

Язык: Английский

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Narrow Dietary Niche With High Overlap Between Snow Leopards and Himalayan Wolves Indicates Potential for Resource Competition in Shey Phoksundo National Park, Nepal

Ecology and Evolution, Год журнала: 2025, Номер 15(1)

Опубликована: Янв. 1, 2025

ABSTRACT Understanding species' dietary ecology and interspecific interactions is crucial for multi‐species conservation planning. In Central Asia the Himalayas, wolves have recolonized snow leopard habitats, raising considerable concern about resource competition between these apex predators. Using micro‐histological analysis of prey species remains (e.g., hair) in their fecal samples, we determined composition, niche breadth, extent diet overlap two predators Shey Phoksundo National Park, Nepal. We analyzed 152 scat samples collected along 89 survey transects from April to June 2021. Our findings reveal a significant diets (Pianka's index = 0.93), with wolf scats containing 11 10 species, respectively. However, difference selection was apparent, deviations observed expected use indicating non‐random relative availability: Snow leopards exhibited higher occurrence wild items (55.28%), primarily blue sheep ( Pseudois nayaur ) (24.83%), whereas relied predominantly on domestic livestock (67.89%), goats Capra hircus accounting over one‐fourth (29.15%). Yaks Bos grunniens comprised portion biomass consumed by both predators, (43.68%) than (36.47%). Overall, narrow breadth high indicates potential wolves. comprehensive understanding will require further study other axes partitioning, including habitat time. Nevertheless, region's low richness means that, increasing human influence, any reduction or increase could intensify wolves, which implications depredation.

Язык: Английский

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Habitat engineering by an apex predator generates spatial trophic dynamics across a temporal environmental stress gradient

Journal of Animal Ecology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 29, 2025

Abstract Ecosystem engineering is a facilitative interaction that generates bottom‐up extrinsic variability may increase species coexistence, particularly along stress/disturbance gradient. American alligators ( Alligator mississippiensis ) create and maintain ‘alligator ponds’ serve as dry‐season refuges for other animals. During seasonal water recession, these ponds present an opportunity to examine predictions of the stress‐gradient (SGH) intermediate disturbance hypotheses (IDH). To test assumption would facilitate coexistence in stress gradient (seasonal drying), we modelled fish catch‐per‐unit‐effort (CPUE) marshes using long‐term dataset (1997–2022). Stomach contents n = 1677 from 46 species) stable isotopes carbon nitrogen 3978 representing 91 taxa) 2018 2019 were used evaluate effects on trophic dynamics. We quantified diets, niche areas, positions basal‐resource use among habitats between seasons. As environmental increases, changes areas proxy competition SGH IDH. Across data, CPUE increased by factor 12 alligator marsh dried. This validates are important refuge. found 73% diet shifts occurred during dry season but diets differed only 11% comparisons. From wet season, both stomach revealed areas. Direction change depended guild was opposite stable‐isotope stomach‐content niches, except detritivores. Stomach‐content niches generally suggesting decreased consistent with existing theory, yielded opposite. result temporal mismatch reflecting over hours, while integrate weeks. Consumptive have stronger effect than longer time intervals. Overall, our results demonstrated ameliorated deep‐water altering food‐web propose ecosystem engineers at values

Язык: Английский

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The Smooth Snake is not a threat to the Meadow Viper: predator–prey interactions of a reptile specialist snake

Community Ecology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 31, 2025

Язык: Английский

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Assessing changes in arthropod predator–prey interactions through DNA‐based gut content analysis—variable environment, stable diet

Molecular Ecology, Год журнала: 2018, Номер 28(2), С. 266 - 280

Опубликована: Сен. 19, 2018

Analysing the structure and dynamics of biotic interaction networks processes shaping them is currently one key fields in ecology. In this paper, we develop a novel approach to gut content analysis, thereby deriving new perspective on community interactions their responses environment. For this, use an elevational gradient High Arctic, asking how environment species traits interact predator-prey involving wolf spider Pardosa glacialis. To characterize potential prey available predator, used pitfall trapping vacuum sampling. actually consumed, applied molecular analysis. Using joint distribution models, found elevation vegetation mass explain most variance composition locally available. However, such environmental variables had only small effect spider's gut. These observations indicate that exerts selective feeding particular taxa irrespective constraints. By directly modelling probability predation based data, neither trait matching terms predator body size nor phylogenetic or constraints modified probability. Our results taxonomic identity may be more important for than traits. The impact change thus appears indirect mediated by its imprint prey.

Язык: Английский

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One‐locus‐several‐primers: A strategy to improve the taxonomic and haplotypic coverage in diet metabarcoding studies

Ecology and Evolution, Год журнала: 2019, Номер 9(8), С. 4603 - 4620

Опубликована: Март 18, 2019

In diet metabarcoding analyses, insufficient taxonomic coverage of PCR primer sets generates false negatives that may dramatically distort biodiversity estimates. this paper, we investigated the and complementarity three cytochrome c oxidase subunit I gene (COI) based on in silico analyses conducted an vivo evaluation using fecal spider web samples from different invertivores, environments, geographic locations. Our results underline lack predictability both individual sets: (a) sharp discrepancies exist observed between (to detriment analyses); (b) depend greatly predator level at which preys are considered; (c) sets' is greatest fine levels (molecular operational units [MOTUs] variants). We then formalized "one-locus-several-primer-sets" (OLSP) strategy, is, use several target same locus (here first part COI gene) group taxa invertebrates). The proximal aim OLSP strategy to minimize by increasing total through multiple sets. illustrate especially relevant perspective since distinct variants within MOTUs were not equally detected across all Furthermore, produces largely overlapping comparable sequences, cannot be achieved when targeting loci. This facilitates haplotypic diversity information contained datasets, for example, phylogeography finer prey-predator interactions.

Язык: Английский

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Pterosaur dietary hypotheses: a review of ideas and approaches

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2018, Номер 93(4), С. 2021 - 2048

Опубликована: Июнь 7, 2018

ABSTRACT Pterosaurs are an extinct group of Mesozoic flying reptiles, whose fossil record extends from approximately 210 to 66 million years ago. They were integral components continental and marginal marine ecosystems, yet their diets remain poorly constrained. Numerous dietary hypotheses have been proposed for different pterosaur groups, including insectivory, piscivory, carnivory, durophagy, herbivory/frugivory, filter‐feeding generalism. These hypotheses, subsequent interpretations diet, supported by qualitative (content fossils, associations, ichnology, comparative anatomy) and/or quantitative (functional morphology, stable isotope analysis) evidence. Pterosaur scattered throughout the literature with little attention paid supporting Reaching a robustly consensus on is important understanding evolution, roles in ecosystems. A comprehensive examination identified 314 (dietary statement plus evidence) 126 published studies. Multiple alternative hypothesised most principal taxonomic groups. Some groups exhibit high degree consensus, multiple lines evidence, while others less consensus. Qualitative evidence supports 87.3% interpretations, anatomy common (62.1% total). More speciose tend greater range diets. Consideration within phylogenetic contexts reveals levels between equivalent monofenestratan lower non‐monofenestratan Evaluating possible non‐biological controls apparent patterns diversity that numbers through time no correlation publication (number peer‐reviewed publications time). 73.8% 21st century. Overall, better accounted signals, such as impact respective quality research levels. That many based qualitative, often untestable adds significant noise data. experiment‐led research, consideration pterosaurs organisms independent evolutionary histories, will lead more robust conclusions drawn repeatable results. This allow diversity, disparity evolution facilitate reconstructions

Язык: Английский

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