Jamming Effects on Soil Degradation Course in Three Gorges Reservoir Region- Regarding The District Where Soil Is Originated From Efflorescent Granite As Example

摘要

Regarding The District Where Soil Is Originated From Efflorescent Granite As Example, this research studied effects of different jamming, such as deforestation, reforestation, setting apart the hills for tree planting, botanic belts and agroforestry, on soil moisture-holding capacity, soil aggregate stability, soil chemical characters and soil respiration. The result display: after deforestation, the first and second year, soil volume weight increases 0.1 annually, soil maximum moisture-holding capacity decreases 20% annually; In three years after deforestation, soil wet aggregate decrease 37.8% annually, dynamic change curve of soil organic matter and total N display like S in reverse, the maximum change velocity occurs in the second year to the third year; soil respiration quantity ranges from 0.9 g C/m~2/day to 7.4 g C/m~2/day under different jamming, the effects boosting up ability agroforestry > reforestation > botanic belts; deforestation do great destroy to soil respiration.