The influences of geology and land use on macroinvertebrate communities were investigated in the Motueka River catchment, New Zealand. Comparisons of functional feeding groups, multivariate community composition and biotic indices (MCI, QMCI, %EPT) were made between native forest stream reaches that differed in subcatchment geology (ultramafic, hard sedimentary, granite, gravel, karst) and between stream reaches surrounded by different land uses (native forest, exotic forest and pasture) within two of these geologies (granite, gravel). Differences in invertebrate community density and taxon richness were greater across the three land uses in the same geology than among the five geologies. Macroinvertebrate communities in streams flowing through native forest had greater numbers of shredders, and higher MCI scores than pastoral streams. Exotic forest macroinvertebrate communities were similar to the native forest communities in granite geology, but distinct from both native and pastoral communities in sites with underlying gravel geology. The results demonstrate that there is potential for underlying geology to influence the magnitude of land use impacts on invertebrate communities. The geologies within a catchment should be accounted for when considering the consequences of land development on river and stream communities.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.