The quantification of local substrate heterogeneity in streams and its significance for macroinvertebrate assemblages
Boyero, Luz (2003) The quantification of local substrate heterogeneity in streams and its significance for macroinvertebrate assemblages. Hydrobiologia, 499 (1). pp. 161-168.
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The effect of substrate heterogeneity on the structure of stream macroinvertebrate assemblages (total abundance, taxon richness, and evenness) is still not clear, but this could be due to the lack of standard methods for quantifying substrate heterogeneity. An accurate quantification of substrate heterogeneity was obtained from photographs of sampled areas (each 225 cm2), which were used to create maps that were subsequently digitized and analyzed using image analysis software. These maps allowed the calculation of multiple metrics quantifying two aspects of substrate heterogeneity: composition and spatial configuration of substrate patches. The diversity of substrate types (calculated as the Shannon diversity index), and the heterogeneity of patch compactness (calculated as the coefficient of variation of the relationship between patch dimensions) were the metrics explaining more biotic variance at the sample scale, but at higher scales there were no relationships between assemblage structure and substrate heterogeneity. Most variation in substrate heterogeneity occurred at the sample scale, while some metrics varied significantly at riffle or segment scales; these patterns of variation match those of macroinvertebrate assemblages, which had been previously studied. The importance of quantifying substrate heterogeneity and considering the spatial scales of its study are discussed.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||spatial heterogeneity; stream substrate; patch; spatial scales; macroinvertebrate assemblages; tropical biology|
|Date Deposited:||09 Mar 2010 05:47|
|FoR Codes:||06 BIOLOGICAL SCIENCES > 0602 Ecology > 060204 Freshwater Ecology @ 50%
06 BIOLOGICAL SCIENCES > 0602 Ecology > 060202 Community Ecology (excl Invasive Species Ecology) @ 50%
|SEO Codes:||96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960807 Fresh, Ground and Surface Water Flora, Fauna and Biodiversity @ 50%
96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960506 Ecosystem Assessment and Management of Fresh, Ground and Surface Water Environments @ 50%