Understanding the concordance among different assemblages as well as their responses to the environmental
gradients at multiple spatial scales is an important issue in conservation biology and in the
assessment of ecological integrity. We examined the community concordance among diatoms, macroinvertebrates
and fish in minimally disturbed streams on four nested spatial scales (i.e., national, catchment,
sub-catchment and mountain or lowland at sub-catchment scales) in Korea. The results, based on nonmetric
multidimensional scaling, showed that diatoms, macroinvertebrates and fish displayed consistent
patterns that were strongly structured along an altitude gradient at the national scale. However, the
responses to all other influential environmental factors differed by assemblages. The community composition
of fish closely reflected the gradients of larger scale environmental factors (i.e., geographical
and hydrological variables), whereas macroinvertebrates mainly reflected the changes at relatively finer
environmental scales (e.g., hydrological variables and substrate composition). Diatoms showed relatively
weak relationships with environmental variables except for the altitudinal gradient. Community
concordance based on Protest was significant at four nested spatial scales, although most cases of community
concordances were relatively weak. Fish and macroinvertebrates showed high concordance at
the national and catchment scales, whereas macroinvertebrates and diatoms showed high concordance
at smaller scales (i.e., mountain or lowland at sub-catchment). Finally, our study demonstrated that community
concordance among diatoms, macroinvertebrates and fish would be different according to spatial
scales and even in the same scales and that use of a representative taxon to assess ecological integrity
should be applied with caution.
Understanding the concordance among different assemblages as well as their responses to the environmentalgradients at multiple spatial scales is an important issue in conservation biology and in theassessment of ecological integrity. We examined the community concordance among diatoms, macroinvertebratesand fish in minimally disturbed streams on four nested spatial scales (i.e., national, catchment,sub-catchment and mountain or lowland at sub-catchment scales) in Korea. The results, based on nonmetricmultidimensional scaling, showed that diatoms, macroinvertebrates and fish displayed consistentpatterns that were strongly structured along an altitude gradient at the national scale. However, theresponses to all other influential environmental factors differed by assemblages. The community compositionof fish closely reflected the gradients of larger scale environmental factors (i.e., geographicaland hydrological variables), whereas macroinvertebrates mainly reflected the changes at relatively finerenvironmental scales (e.g., hydrological variables and substrate composition). Diatoms showed relativelyweak relationships with environmental variables except for the altitudinal gradient. Communityconcordance based on Protest was significant at four nested spatial scales, although most cases of communityconcordances were relatively weak. Fish and macroinvertebrates showed high concordance atthe national and catchment scales, whereas macroinvertebrates and diatoms showed high concordanceat smaller scales (i.e., mountain or lowland at sub-catchment). Finally, our study demonstrated that communityconcordance among diatoms, macroinvertebrates and fish would be different according to spatialscales and even in the same scales and that use of a representative taxon to assess ecological integrityshould be applied with caution.
การแปล กรุณารอสักครู่..
