摘要：The Buffalo River in north-central Arkansas is approximately 246 km long and flows through the Boston Mountains and Springfield and Salem Plateaus to the White River near Buffalo City. The Buffalo River is America’s first National River with the National Park Service owning 11% of land in the watershed. The objectives of this project were to survey the entire perennially wet length of river, search for mussels of conservation concern, and document the freshwater mussel assemblages. During 2004 and 2005, 235 km of the river were qualitatively and quantitatively surveyed. We documented 64 mussel assemblages. Time constrained qualitatively sampled assemblages (n=41) resulted in a mean richness of 7.8 with a range of 2 to 12 species. Quantitatively sampled mussel assemblages (n=23) had a mean richness of 9.5, ranging from 4 to 16 species and a mean density of 6.9 individuals/m2 , ranging from 1.3 to 25.6 individuals/m2 . Detrended correspondence analysis revealed 4 distinct community types dominated by: 1) Ptychobranchus occidentalis (Conrad 1836), 2) Villosa iris (Lea 1829), 3) Cyclonaias tuberculata (Rafinesque 1820), and 4) Actinonaias ligamentina (Lamarck 1819) that represented approximate species gradients along the river’s length. Previous surveys collectively recorded a total of 26 species for the river, however; only 23 species were identified in this survey with no federally listed threatened or endangered species found. The Buffalo National River has a moderately diverse and abundant native freshwater mussel fauna. Seventy-eight percent of the current species are considered to be of conservation concern (S1-S3). Consequently, the Buffalo National River may prove to be an important refuge for a declining mussel resource.
