荒漠草原区固沙人工柠条林生长过程中土壤性质演变规律

开展荒漠草原区固沙人工林生长过程中土壤性质研究,对于沙化草地土壤质量演变规律分析和人工林有效管理均具有重要的指导价值。通过野外调查取样和室内分析,测定6,15,24,36年柠条林地土壤机械组成、土壤养分、pH和电导率以及土壤水分与温度等指标变化,分析荒漠草原区种植固沙柠条人工林对土壤性质的影响。结果表明,从6年到15年柠条林地,土壤粗沙粒和细沙粒成分显著升高(P<0.05),但从24年柠条林地开始土壤粗沙粒和细沙粒含量显著下降(P<0.05),土壤极细沙粒和粘粉粒含量开始显著增加(P<0.05)。从24年柠条林地开始,土壤有机碳、全N和全P含量显著升高,土壤电导率和水分含量呈现增加趋势,而土壤pH和温度显著下降;而且土壤全N积累量高于土壤有机碳,土壤C/N随着柠条林龄的增加呈逐渐下降趋势。在荒漠草原区,人工柠条林发育生长有利于土壤肥力的提高和土壤环境的改善,而且需要经历一个较长的发育过程。

Soil Properties Following Growing Process of Artificial Forests(Caragana microphylla) in Desert Steppe

The soil properties during the growing process of artificial forest(C.microphylla) were a valuable indicator for soil quality and rational management of desert steppe.The soil mechanical composition,nutrient,pH and electrical conductivity,together with soil temperature and moisture,were measured by field sample and indoor analysis in desert steppe.The results showed that the soil coarse sand and fine sand content increased significantly with marked decrease in soil very fine sand content from 6 to 15 years of C.microphylla forests(P<0.05).But the significant decrease in soil coarse and fine sand content,and the significant increase in soil very fine sand and silt clay content were found beginning from of 24-year forests(P<0.05).At the same time,the soil organic carbon,total N and total P,together with soil electrical conductivity and moisture were all significantly enhanced(P<0.05),with the marked decrease in soil pH and temperature(P<0.05).The cumulative content of soil total nitrogen was higher than that of soil organic carbon,and soil C/N tended to decrease following growing process of these artificial forests.It was suggested that the growing process of C.microphylla forests could facilitate the improvement of soil fertility and microhabitat,and it needed a long time.