Effects of symbiotic N-fixation on nitrogen enrichment of floodplain soils
River floodplains are disturbed ecosystems. Sediments in floodplains are generally coarse and low in nutrients, especially nitrogen is very limiting. These characteristics inhibit the development of dense communities of herbaceous plants. Nitrogen fixation by symbiotic legumes is an important process of nitrogen enrichment in floodplain soils, particularly in the earlier stage of succession. We hypothesized that symbiotic nitrogen enrichment is greatly influenced by soil factors, especially soil nitrogen content. To test this hypothesis, we collected soil and plant samples along four sites along the bank of Tama River, Japan. Soil and plant nitrogen contents, the faction of fixed nitrogen etc. were analyzed. Soil nitrogen values were higher at high elevation sites. There was a significant difference in nitrogen fixation among study sites, low at high elevation sites and high at low elevation, suggesting that flooding disturbance flushes nutrient rich soils. Fractionation of 15N values in leaf tissues (?15N) suggests that nitrogen fixation was extensive at the site lower than 0.2% of total nitrogen content in the soil.
Nitrogen fixation floodplain soil legume vine vegetation succession flooding disturbance
Takashi Asaeda Md H.Rashid Kohsuke Ohta
Institue for Environmental Science & Technology, Saitama University, Saitama 338-8570, Japan Department of Environmental Science & Technology, Saitama University, Saitama 338-8570, Japan
国际会议
The 3rd Biennial ISRS Symposium Achieving Healthy and Viable Rivers (ISRS)第3届国际河流大会
北京
英文
622-628
2013-08-05（万方平台首次上网日期，不代表论文的发表时间）