西北干旱区植被恢复的土壤养分效应

通过对西北干旱区植被恢复过程中不同退耕模式下土壤养分的变化、土壤各养分的时空分布及各养分间的相关性分析,系统研究了干旱区植被恢复过程中土壤环境变化特征和规律。结果表明,在西北干旱区,进行植被恢复能明显改善土壤肥力状况,但不同植被恢复方式对土壤的腐殖化作用差异显著,依次为侧柏＋灌木＋苜蓿〉侧柏＋苜蓿〉侧柏＋灌木〉侧柏,而且随着植被恢复年限的持续,土壤中各养分质量分数明显增加。不同养分对植被恢复的响应程度从高到低表现为：速效磷〉速效氮〉速效钾〉全氮〉有机质〉全磷〉全钾。同时,相关性分析表明,土壤有机质的变化与全氮、速效氮呈现出显著的相关性,R2为0.867和0794,并且各养分具有明显的表聚性,尤以有机质、速效磷和速效氮表现明显。

Impact of vegetation regeneration on soil nutrient variation in central arid region of Gansu province

We analyzed soil nutrients variation and spatial distribution under different restoration models,as well as studied the correlations among soil nutrients in the process of vegetation restoration of northwest China.Comprehensively analyzed the soil environment change characters and mechanisms in reforestation sites of arid region.The results showed that in semi-arid region,restoration can clearly improve soil fertility conditions,but different restorations demonstrated significant difference to soil humification,the order of different roles to soil humification is： oriental arborvitae ＋ korshinsk peashrub ＋ alfalfa oriental arborvitae ＋ alfalfa oriental arborvitae ＋ korshinsk peashrub korshinsk peashrub.Meanwhile,with the tree planting year extension,soil nutrients content significantly increased.The results also revealed that soil nutrients respond to the process of community succession in the following order： APANAKTNOMTPTK.In addition,there were strong correlations among soil organic matter（SOM） and other soil nutrient parameters,such as total nitrogen,available nitrogen.The correlation coefficients（R2） among them is 0.867 and 0.794.During the restoration process,nutrients,especially the soil organic matter,available phosphorus and available nitrogen,concentrated in the surface layer.