Skip to Main Content
Dynamics in species composition of stream fish assemblages: environmental variability and nested subsetsAuthor(s): Christopher M. Taylor; Melvin L. Warren
Source: Ecology. 82(8): 2320-2330.
Publication Series: Miscellaneous Publication
PDF: Download Publication (198 KB)
DescriptionStream landscapes are highly variable in space and time and, like terrestrial landscapes, the resources they contain are patchily distributed. Organisms may disperse among patches to fulfill life-history requirements, but biotic and abiotic factors may limit patch or locality occupancy. Thus, the dynamics of immigration and extinction determine, in part, the local structure of assemblages. We sampled fishes and stream habitat at 12 localities for two years (96 samples) to examine the deterministic nature of immigration and extinction processes in stream fish assemblages. Mean immigration rates for assemblages were highest at large stream localities, where the pool of potential immigrants was largest. Mean extinction rates were highest where variability in the flow regime was high, though local refugia appeared to modify the extinction process at one locality. Significant nested subset patterns in species composition occurred over time for 7 of the 12 localities. The strength of the nesting was associated with mean immigration and extinction rates. Higher extinction rates corresponded to stronger nestedness, whereas higher immigration rates were associated with weaker nestedness. Across all species, both immigration and extinction rates were strongly associated with mean abundance. Species with high local abundances had higher immigration rates and lower extinction rates than did species with low local abundances. There were no significant associations between trophic guild or body size and immigration and extinction rate. This work supports the hypothesis that immigration and extinction rates for assemblages are predictable along environmental gradients, and that species are less prone to local extinction and more prone to colonize areas when they maintain high local abundances. The extinction process in local assemblages can be a highly ordered event leading to strong nested subset patterns, but immigration appears to be more stochastic.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationTaylor, Christopher M.; Warren, Melvin L., Jr. 2001. Dynamics in species composition of stream fish assemblages: environmental variability and nested subsets. Ecology. 82(8): 2320-2330.
- Distribution, abundance, and diversity of stream fishes under variable environmental conditions
- Fish Assemblage Structure Under Variable Environmental Conditions in the Ouachita Mountains
- Vertebrate assemblages associated with headwater hydrology in western Oregon managed forests.
XML: View XML