摘要
利用 5～ 6a野外径流小区试验资料 ,研究 1 7种植被覆盖对土壤侵蚀和氮素流失的影响 ,结果表明 :1 9种作物、4种草地和 4种草灌间作小区年平均径流量为 2 7773、1 80 2 8和 1 31 4 9m3/ km2 · a,比相应裸地减少 2 7.5%、51 .1 %和64.3% ;侵蚀模数为 1 71 6、1 0 2 1和 81 2 t/ km2 · a,减少 73.0 %、92 .8%和 94 .3% ;全氮富集率为 1 .65、2 .4 8和 2 .59,比裸地增加 1 3.8%～ 1 1 4 % ;年平均土壤氮素流失量为 1 4 58、1 2 52、382 9和 966kg/ km2· a。 2植被通过调节径流流速来间接影响泥沙全氮富集 ,土壤侵蚀模数愈大 ,泥沙全氮富集率愈小。 3土壤氮素流失方程 SN=( 55.56-4 .87ln SL)· SL·TN ,可定量预测土壤氮素的流失。
The soil erosion and N loss by erosion as affected by vegetation was conducted in field runoff plots for 5～6 years. The results showed that the mean runoff amounts of 9 crops, 4 grasses, 4 grass shrubs fields were of 27773,18028 and 13149 m 3/km 2·a respectively, which were 27.5%, 51.1% and 64.3% lower than bare land. Their erosion modules were 1716, 1021 and 812t/km 2·a,which were 73 0%, 92.8% and 94.3% lower respectively than the bare land respectively. Their mean loss amounts of nitrogen by sediment were 1458,1252 and 966 kg/km 2·a. Vegetation affected indirectly the nitrogen enrichment in sediment by way of regulating runoff velocity on the slope surface.A model of soil N loss,was developed to predict the soil nitrogen loss by sediment.
出处
《生态学报》
CAS
CSCD
北大核心
2000年第6期1038-1044,共7页
Acta Ecologica Sinica
基金
中国科学院知识创新工程项目!( KZCX2 -4 1 1 )
"973"项目!( G1 9990 1 1 70 9)
国家自然科学基金资助项目!( 49871 0 4 9)
关键词
植被类型
土壤侵蚀
氮素流失
vegetation type
soil erosion
nitrogen loss
