The “Danxia landform” is an erosional landform type originally defined in China. It is characterized by redcolored sandstones and steep cliffs, and developed via long-term erosion. Detailed quantitative geomorphometric studies of the characteristics of Danxia landforms in China have not yet been conducted. Using GIS, we conducted DEM-based geomorphometric analyses of 42 watersheds on Mt. Danxia...

Physiologic activity and community structure of planktonic and biofilm microbial communities in an urban river were analyzed using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) staining, fluorescent in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) analysis of polymerase chain reaction (PCR)-amplified 16S rDNA fragments. Respiring bacteria estimated by CTC reducti...

Climate warming is likely to cause both indirect and direct impacts on the biophysical properties of stream ecosystems especially in regions that support societally important fish species such as Pacific salmon. We studied the seasonal variability and interaction between stream temperature and DO in a low-gradient, forested stream and a glacial-fed stream in coastal southeast Alaska to assess h...

Multiple stressors threaten stream physical and biological quality, including elevated nutrients and other contaminants, riparian and in-stream habitat degradation and altered natural flow regime. Unconventional oil and gas (UOG) development is one emerging stressor that spans the U.S. UOG development could alter stream sedimentation, riparian extent and composition, in-stream flow, and water q...

2 Extension Range Specialist and Research Scientist, University of Nevada, Department of Range Wildlife and Forestry, Reno, Nevada. Abstract: Historic use of many stream riparian areas and associated watersheds has impaired the capacity of riparian vegetation and floodplains to reduce stream energy and trap sediments. As low-gradient streams with erodible banks increase in width and change thei...

The influence of stream age and environmental variables on meiofaunal assemblages were examined for 15 streams across a temporal gradient of 200 yr in Glacier Bay National Park, southeast Alaska. Meiofaunal assemblages were found in all streams but varied in diversity and abundance. Copepod species found had a wide range of habitat affinities and good dispersal abilities; we argue that the obse...

Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg) in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic re...