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Factors Affecting Macroinvertebrate Richness and Diversity in Portuguese Streams: a Two‐Scale Analysis
Author(s) -
Graça Manuel A. S.,
Pinto Paulo,
Cortes Rui,
Coimbra Nuno,
Oliveira Simone,
Morais Manuela,
Carvalho Maria João,
Malo Jorge
Publication year - 2004
Publication title -
international review of hydrobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 1434-2944
DOI - 10.1002/iroh.200310705
Subject(s) - species richness , streams , invertebrate , ecology , sampling (signal processing) , mediterranean climate , abundance (ecology) , taxon , environmental science , spatial ecology , organic matter , hydrology (agriculture) , biology , geology , computer network , geotechnical engineering , filter (signal processing) , computer science , computer vision
We analysed the spatial patterns in macroinvertebrate taxon richness and abundance at two scales: sampling unit and basin. We sampled 12 stream sites in three zones of Portugal, differing in climate geomorphology and water chemistry. At a sampling unit scale, substratum organic matter content, depth and the dominant size of substratum particles were correlated with numbers of taxa and individuals. We propose that the number of taxa at a small scale depends on the number of individuals, which in turn is the result of organic matter accumulation, hydrologic and substratum characteristics. The environmental parameters better explaining the large‐scale biological data were temperature, minimum size of substratum particles and pH. Regardless of the relative importance of variable types and mechanisms regulating stream invertebrates along the climatic gradient, rivers from the North and Centre appeared to be richer in taxa than the typically Mediterranean streams in the South.