摘要：Three third order Ozark streams in different watersheds were sampled quantitatively to determine if rootmats harbored an insect community distinct from other lotic communities. Samples were taken from pools, riffles, and rootmats in each stream. The communities were compared based on taxonomic richness, abundance, diversity, and composition. Whereas diversity and richness were not significantly different among mesohabitats, abundance was greater in rootmats than in pools and riffles. The taxonomic composition of rootmat communities was more dissimilar to those of pools and riffles than were pool and riffle communities to each other. Of the 75 taxa collected, 13 were unique to rootmats and seven each to riffles and pools. Further, it appeared that several taxa, not necessarily unique to rootmats, utilized rootmats at some point in their life history (i.e., pupation, oviposition). The results indicate that submerged rootmats harbor a distinct and abundant insect fauna that likely plays an integral part in stream ecosystems.
