Effects of rural development on the water quality of central Thailand streams

Abstract

            Tropical streams provide a variety of valuable goods (e.g., food, water) and services (e.g., swimming, effluent disposal) to local inhabitants. Rural development of catchments threatens these resources as forests adjacent to streams are removed and replaced with other land uses. This study examined the effect of rural development on the water quality of a tropical stream as reflected by the benthic macroinvertebrate fauna. Differences in the composition of benthic macroinvertebrate fauna were noted among sites that differed in riparian forest cover. The density of benthic macroinvertebrates was Higher at three rural sites compared with a forested reference site; taxa richness was slightly higher. The percent of local forest cover along the stream accounted for the difference in benthic macroinvertebrate and scraper density at the sites. Solar irradiance explained many of the differences in the benthic fauna. It appears that the benthic fauna in tropical streams responds to changes in land use in a similar manner to those in temperate streams.