Assessment of ecological characteristics of macroinvertebrate communities and their relationship with environmental factors in a stream ecosystem

Abstract

ABSTRACT We explored the spatial and temporal variations in the ecological characteristics of the macroinvertebrate community in relation to the environmental factors from the Vishav stream basin of Kashmir Himalaya from March 2013 to February 2015. We collected water quality and biological data from five locations within the stream basin. Integrated water quality and biological approach indicated the clean water conditions with pollution-sensitive macroinvertebrates at an upstream site located well within the forest area. In response to changing water quality with increasing agricultural and other anthropogenic activities, there was an increase in the number of macroinvertebrate taxa at middle and downstream sites, mostly moderately and highly pollution tolerant taxa. Harsh in-stream environmental conditions (high discharge and stream water velocity) at the upstream site resulted in lower values of alpha diversity metrics. Despite statistically significant spatial variations, macroinvertebrates remained stable across seasons due to low taxa replacement and harshness of climatic factors. Multivariate dispersion homogeneity and composition analysis showed that the macroinvertebrate composition varied similarly among sites, with different compositions. Distance-based redundancy analysis indicated that water temperature, discharge, dissolved oxygen, pH and total phosphorus are major environmental factors determining the benthic macroinvertebrate diversity (alpha diversity) and composition (beta diversity) throughout the study area.