A test of the loose-equilibrium concept with long-lived organisms: Evaluating temporal change in freshwater mussel assemblages.

Autor: Hopper GW; School of Renewable Natural Resources, Louisiana State University and Agricultural Center, Baton Rouge, Louisiana, USA., Miller EJ; Kansas Department of Wildlife and Parks, Independence, Kansas, USA., Haag WR; US Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research, Frankfort, Kentucky, USA., Vaughn CC; Oklahoma Biological Survey and Department of Biology, University of Oklahoma, Norman, Oklahoma, USA., Hornbach DJ; Department of Environmental Studies, Macalester College, St. Paul, Minnesota, USA., Jones JW; U.S. Fish and Wildlife Service, Department of Fish and Wildlife Conservation and Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA., Atkinson CL; Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
Jazyk: angličtina
Zdroj: The Journal of animal ecology [J Anim Ecol] 2024 Mar; Vol. 93 (3), pp. 281-293. Date of Electronic Publication: 2024 Jan 19.
DOI: 10.1111/1365-2656.14046
Abstrakt: The loose-equilibrium concept (LEC) predicts that ecological assemblages change transiently but return towards an earlier or average structure. The LEC framework can help determine whether assemblages vary within expected ranges or are permanently altered following environmental change. Long-lived, slow-growing animals typically respond slowly to environmental change, and their assemblage dynamics may respond over decades, which transcends most ecological studies. Unionid mussels are valuable for studying dynamics of long-lived animals because they can live >50 years and occur in dense, species-rich assemblages (mussel beds). Mussel beds can persist for decades, but disturbance can affect species differently, resulting in variable trajectories according to differences in species composition within and among rivers. We used long-term data sets (10-40 years) from seven rivers in the eastern United States to evaluate the magnitude, pace and directionality of mussel assemblage change within the context of the LEC. Site trajectories varied within and among streams and showed patterns consistent with either the LEC or directional change. In streams that conformed to the LEC, rank abundance of dominant species remained stable over time, but directional change in other streams was driven by changes in the rank abundance and composition of dominant species. Characteristics of mussel assemblage change varied widely, ranging from those conforming to the LEC to those showing strong directional change. Conservation approaches that attempt to maintain or create a desired assemblage condition should acknowledge this wide range of possible assemblage trajectories and that the environmental factors that influence those changes remain poorly understood.
(© 2024 The Authors. Journal of Animal Ecology © 2024 British Ecological Society.)
Databáze: MEDLINE
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