| Budget Amount *help |
¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000)
Fiscal Year 2014: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2013: ¥7,280,000 (Direct Cost: ¥5,600,000、Indirect Cost: ¥1,680,000)
Fiscal Year 2012: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
|
|---|
| Outline of Final Research Achievements |
Riparian zone is low in nutrients subjected to flood disturbances. Total nitrogen (N) contents and the fraction of 15N in soil were estimated using N stable isotope analyses and the amount of N-fixation was calculated. It was found that N-fixation rate decreases with increasing soil N concentration. An empirical formula was derived for a practical use. Initially, N accumulation in shoreline is very low due to the frequent inundation and disturbances. In the course of plant colonization, N enrichment occurs in the shoreline mostly by N-fixation. It was also found that biomass of shoreline herbs increases with soil N concentration; the relationship follows a simple empirical formula. Together with other influential factors for herb biomass and the recruitment and growth of trees, a prediction model for the riparian vegetation and soil nutrients were developed for the river management. The model was applied to several rivers and extremely good agreement was obtained with field surveys.
|
