晋西黄土区不同退耕年限刺槐林对土壤水分和养分的影响

目的]探讨人工刺槐林植被恢复对土壤水分和养分的影响,为半干旱黄土丘陵区植被恢复与生态建设提供理论依据。方法]选择山西省黄河中游典型黄土丘陵沟壑区的人工刺槐林为研究对象,评估不同退耕年限刺槐林地土壤水分和养分特征。结果]刺槐林地能够有效改善土壤水分条件,尤其在造林初期,土壤有机质和全氮平均含量显著提高,且具有明显的表聚性;刺槐林地对浅层土壤水分和养分的改善作用较大,土壤水分在40cm以上土层坑内平均水分比坑外提高了3.97%,在40cm以下土层仅提高了2.74%;土壤养分在20cm以上土层,坑内土壤有机质、全氮、全磷和全钾平均含量分别比坑外提高了6.61%,6.14%,1.55%和1.98%;在20cm以下土层,对土壤全磷和全钾无明显改善作用。结论]刺槐林地不同程度地改善和提高了于浅层坑内土壤水分和养分状况。

Effects of Robinia Psedudoacia Vegetation Restoration on Soil Moisture and Nutrient in Loess Hilly Region of Western Shanxi Province

Objective] To explore the effects of Robinia psedudoacia plantations on the soil moisture and nutrient characteristics, in order to provide theoretical basis for vegetation restoration and ecological reconstruction in semiarid loess hilly region.Methods] Based on data collected from soil sampling in the field and laboratory measurement, the soil moisture and nutrient characteristics under different R. psedudoacia plantations with various ages were analyzed in the loess hilly region of western Shanxi Province.Results] R. psedudoacia plantanations effectively improved soil moisture conditions, especially in the early stages of the planting. The average content of soil organic content and total nitrogen increased significantly, and showed an apparent surface aggregation. Surface soil moisture and nutrient conditions were better than that of the underlying soil layers after R. psedudoacia restoration. Soil moisture inside the pits above 40 cm was 3.97% higher than that outside the pits, and 2.74% higher in soil below 40 cm. Soil organic content, total nitrogen, total phosphorus and total potassium inside the pits was increased by 6.61%, 6.14%, 1.55% and 1.98% respectively, than those outside the pit at 0-20 cm soil layer, while there were no significant improvements for the total phosphorus and the total potassium content below 20 cm soil layer.Conclusion] R. psedudoacia plantanations has improved moisture and nutrients conditions in surface soil layers.