Habitat filtering determines spatial variation of macroinvertebrate community traits in northern headwater streams

• Published in: Community ecology Vol. 14; no. 1; pp. 77 - 88
• Main Authors: Schmera, D, T. Erős, J. Heino
• Format: Journal Article
• Language: English
• Published: Cham Akadémiai Kiadà 01.06.2013; AKADÉMIAI KIADÓ; Springer International Publishing
• Subjects: Animal Ecology; aquatic invertebrates; Biodiversity; Community & Population Ecology; Diversity; environmental assessment; environmental degradation; environmental factors; Freshwater ecology; habitats; Headwater streams; Headwaters; latitude; Life Sciences; linear models; Macroinvertebrates; Marine & Freshwater Sciences; Microbial Ecology; multivariate analysis; Music analysis; Natural environmental variation; Plant Ecology; species diversity; Stream habitats; Stream macroinvertebrates; Streams; Sustainable communities; Synecology; Taxa; Trait-based analyses; Watersheds; Finland; Natural environmental variation; Headwater streams; Stream macroinvertebrates; Trait-based analyses; Diversity
• ISSN: 1585-8553; 1588-2756
• DOI: 10.1556/ComEc.14.2013.1.9

Although our knowledge of the spatial distribution of stream organisms has been increasing rapidly in the last decades, there is still little consensus about trait-based variability of macroinvertebrate communities within and between catchments in near-pristine systems. Our aim was to examine the taxonomic and trait based stability vs. variability of stream macroinvertebrates in three high-latitude catchments in Finland. The collected taxa were assigned to unique trait combinations (UTCs) using biological traits. We found that only a single or a highly limited number of taxa formed a single UTC, suggesting a low degree of redundancy. Our analyses revealed significant differences in the environmental conditions of the streams among the three catchments. Linear models, rarefaction curves and beta-diversity measures showed that the catchments differed in both alpha and beta diversity. Taxon- and trait-based multivariate analyses also indicated that the three catchments were significantly different in terms of macroinvertebrate communities. All these findings suggest that habitat filtering, i.e., environmental differences among catchments, determines the variability of macroinvertebrate communities, thereby contributing to the significant biological differences among the catchments. The main implications of our study is that the sensitivity of trait-based analyses to natural environmental variation should be carefully incorporated in the assessment of environmental degradation, and that further studies are needed for a deeper understanding of trait-based community patterns across near-pristine streams.