Biology subjects

Zarnetske, P. L.

Publications and source records attributed to Zarnetske, P. L..

7 recordsLinked to original sources

bioRxiv2026

The AvianMetaNetwork: biotic interactions among birds of the continental United States and Canada

All organisms interact with other organisms, directly, and indirectly through different ecological relationships involving multiple types of interactions. Yet at broad continental scales, we lack comprehensive information on biotic interactions, which has hindered our ability to answer macroecological and eco-evolutionary questions across scales and to fully quantify the diversity of biotic interactions as an important dimension of biodiversity. Here, we help fill these gaps with an open and comprehensive dataset and data workflow of 25,907 pairwise, directional interspecific interactions among birds spanning a continental scale. All data are empirically documented and comprise bird-bird interactions across both breeding and non-breeding ranges of 731 focal avian taxa, covering all birds in the focal region of Canada and the continental United States, including Alaska. These data also include 1,258 additional avian taxa interacting with the focal taxa outside the focal region, resulting in 1,989 avian taxa altogether. The continental scale and breadth of interspecific interactions within these data fill fundamental knowledge gaps and enable scientists and practitioners to address a myriad of questions at broader scales than were previously possible.

ecology↗

bioRxiv2026

Six decades of change across all North American bird interaction networks

Species interactions are essential for maintaining biodiversity in the face of global changes. Yet lack of interaction data has hindered progress in understanding spatiotemporal changes in ecological network structure and function. To address this shortfall, we perform network analysis on a continental-scale metanetwork of bird interactions (AvianMetaNetwork), and quantify shifts in trophic, commensalism, parasitism, competition, mobbing, and facilitation networks using 13762 interactions among 687 North American birds. Since 1970, changes in species abundance and human activity drove network shifts, especially in eastern North America. With this metanetwork, we uncovered more than a half century of previously undocumented shifts in the structure of each avian network at a continental scale, with large implications for the functioning of bird communities and the ecosystems that rely on them.

ecology↗

bioRxiv2026

Large language models unlock the ecology of species interactions

Species interactions shape population dynamics, geographic distributions, evolutionary trajectories, and responses to environmental change. Yet data on these interactions remain scarce across broad spatial, temporal, and taxonomic scales because they are difficult to collect in the field. One promising source of interaction data is citizen science platforms, which contain billions of biodiversity observations, often accompanied by unstructured text comments that may document interactions among organisms. Advances in large language models (LLMs) make it increasingly feasible to identify, extract, and categorize biotic interactions from these unstructured data at scale. Here, we present an LLM workflow that collects species interaction observations from multilingual citizen science comments. Using two case studies--bird-bird and plant-pollinator interactions--we show that LLMs can rapidly extract interaction types and participating species with high accuracy. These data can greatly expand the spatial, temporal, and taxonomic coverage and resolution of species interactions data, enable new tests of long-standing ecological questions, and improve our ability to track ecological changes. With appropriate validation, expert review, and attention to data privacy for both users and sensitive species, this approach opens new opportunities to characterize, forecast, and conserve biodiversity under global change.

ecology↗

bioRxiv2025

Abundance redistribution increases predator-prey interaction potentials among North American birds

Species are dramatically shifting their geographical ranges, yet the consequences of these spatial redistributions on species interactions have not been examined at broad spatial and temporal scales. Here, we investigate how the redistribution of species abundance over the past 50 years affects the potential for predator-prey interactions among North American birds. We first predict potential predator-prey interactions based on existing data and functional traits, then construct a novel, abundance-weighted metric of interaction potential for each pair of predator and prey in local communities. Across North America, the potential for predator-prey interactions has been increasing over time. We further show that this widespread increasing trend in interaction potentials is mostly driven by higher abundances of predator species. The spatial redistributions of predators and prey lead to turnover of interactions within local communities, and the turnover is less associated with changes in climate but more associated with human-induced land use changes. Our novel approach and results highlight the importance of considering traits, abundance, and species interactions--including known and potential interactions--when studying the ecological consequences of species range shifts.

ecology↗

bioRxiv2022

Diversity-stability relationships become decoupled across spatial scales: a synthesis of organism and ecosystem types

The relationship between biodiversity and stability, or its inverse, temporal variability, is multidimensional and complex. Temporal variability in aggregate properties, like total biomass or abundance, is typically lower in communities with higher species diversity (i.e., the diversity-stability relationship or DSR). Recent work has shown that, at broader spatial extents, regional-scale aggregate variability is also lower with higher regional diversity (in plant systems) and with lower spatial synchrony. However, it is not yet clear whether regional DSRs hold across a broad range of organisms and ecosystem types. Furthermore, focusing exclusively on aggregate properties of communities may overlook potentially destabilizing compositional shifts. To test these questions, we compiled a large collection of long-term spatial metacommunity data spanning a wide range of taxonomic groups (e.g., birds, fish, plants, invertebrates) and ecosystem types (e.g., deserts, forests, oceans). We applied a newly developed quantitative framework for jointly analyzing aggregate and compositional variability across scales. We quantified DSRs for composition and total abundance in local communities and metacommunities. At the local scale, compositional DSRs suggested that higher local () diversity was associated with lower variability in animal populations but higher variability in plant populations, while aggregate DSRs supported the classic stabilizing effects of diversity. Spatial synchrony differed among taxa (birds had the lowest, plants the highest), suggesting differences in stabilization by spatial processes. Spatial synchrony declined with higher diversity among sites ({beta}) for both compositional and aggregate properties. However, at the regional ({gamma}) scale, we found no aggregate DSR, but a positive compositional DSR. Across a broader range of taxa, our results suggest that high {gamma}-diversity does not consistently stabilize aggregate properties at regional scales without sufficient spatial {beta}-diversity to reduce spatial synchrony. Open research statementAll data sets are accessible via the Environmental Data Initiative, and a specific data package of the data sets used in this analysis will be made publicly available (doi: pending). Citations to original sources are included in Appendix S1. Code to reproduce the analyses is found in a Zenodo archive (doi: pending) of the GitHub repository for this project (https://github.com/sokole/ltermetacommunities/tree/master/Manuscripts/MS3).

ecology↗

bioRxiv2021

The dual nature of metacommunity variability

There is increasing interest in measuring ecological stability to understand how communities and ecosystems respond to broad-scale global changes. One of the most common approaches is to quantify the variation through time in community or ecosystem aggregate attributes (e.g., total biomass), referred to as aggregate variability. It is now widely recognized that aggregate variability represents only one aspect of communities and ecosystems, and compositional variability, the changes in the relative frequency of species in an assemblage, is equally important. Recent contributions have also begun to explore ecological stability at regional spatial scales, where interconnected local communities form metacommunities, a key concept in managing complex landscapes. However, the conceptual frameworks and measures of ecological stability in space have only focused on aggregate variability, leaving a conceptual gap. Here, we address this gap with a novel framework for quantifying the aggregate and compositional variability of communities and ecosystems through space and time. We demonstrate that the compositional variability of a metacommunity depends on the degree of spatial synchrony in compositional trajectories among local communities. We then provide a conceptual framework in which compositional variability of (i) the metacommunity through time and (ii) among local communities combine into four archetype scenarios: spatial stasis (low/low); spatial synchrony (high/low); spatial asynchrony (high/high) and spatial compensation (low/high). We illustrate this framework based on numerical examples and a case study of a macroalgal metacommunity in which low spatial synchrony reduced variability in aggregate biomass at the metacommunity scale, while masking high spatial synchrony in compositional trajectories among local communities. Finally, we discuss the role of dispersal, environmental heterogeneity, species interactions and suggest future avenues. We believe this framework will be helpful for considering both aspects of variability simultaneously which is important to better understand ecological stability in natural and complex landscapes in response to environmental changes.

ecology↗

bioRxiv2020

Life history scaling and the division of energy in forests

The competition for light has long been regarded as a key axis of niche partitioning that promotes forest diversity, but available evidence is contradictory. Despite strong tradeoffs between growth and survival with light, field tests suggest neutral forces govern tree composition across forest gaps and resource use across size classes. Here we integrate scaling and niche theory, and use data from >114,000 woody plants in a tropical, old growth forest to test and predict patterns of niche partitioning with size and light. Consistent with predictions, the relative abundance, production, light capture, and richness of species in life histories with fast growth follow a power law relationship, increasing 1-2 orders of magnitude along a solar and size gradient. Competitive neutrality between size classes emerges above the sapling layer, where increasing access to light is counterbalanced by stronger self-shading. Convergent power law patterns of resource partitioning across taxa and spatial scale suggest general life history tradeoffs drive the organization of diverse communities.

ecology↗