不同植被恢复模式对黄土丘陵区土壤抗蚀性的影响

Effects of different vegetation restoration models on soil anti-erodibility in loess hilly area

提高土壤抗蚀性是防治土壤侵蚀、促进生态恢复的有效途径之一。以退耕1a撂荒地作为对照,该研究通过对恢复30a的刺槐、柠条、油松与刺槐-紫穗槐、油松-紫穗槐5种不同植被恢复模式进行土壤抗蚀性的探索研究,结果表明,与对照相比,不同植被恢复模式的土壤抗蚀性均明显增强,土壤有机质含量、土壤黏粒含量以及土壤颗粒间团聚程度显著提高。采用土壤有机质含量、水稳性团聚体含量、水稳性团粒平均质量直径、团聚度和分散系数等指标计算该区土壤抗蚀性,进行抗蚀性等量评价。不同植被恢复模式土壤抗蚀性大小顺序为:油松(PC16)、刺槐(RP21)、柠条(AK18)、油松-紫穗槐(PA17)和刺槐-紫穗槐(RA20),纯林土壤抗蚀性强于混交林。该区采用油松、刺槐和柠条纯林恢复模式效果要优于油松-紫穗槐和刺槐-紫穗槐混交模式。

Improving soil anti-erodibility is the effective approach to prevent soil erosion and restore vegetation.One year abandoned land was taken as control,the soil-erodibility of five vegetation restoration models such as Robinia pseudoacacia L. (RP21),Caragana korshinkii Kom.(AK18),Pinus tabulaeformis Carr.(PC16),R.pseudoacacia-A.fruticosa(RA20),P. tabulaeformis-Amorpha fruticosa L.(PA17)were studied.The results showed that the soil anti-erodibility was improved obviously compared to fallow land.The contents of soil organic matter,clay particles and aggregate degrees between soil particles were increased obviously.Soil organic matter content,water-stable aggregates content,mean weight diameter of water stable aggregate,aggregate degree and dispersion coefficient were used to evaluate the anti-erodibility quantitatively. The order of anti-erodibility with different vegetation restoration models was:Pinus tabulaeformis Carr.,Robinia pseudoacacia L.,Caragana korshinkii Kom.,P.tabulaeformis-A.furticosa and R.pseudoacacia-A.furticosa.In a word,the soil anti-erodibility of pure forest is higher than that of mix-forest in loess hilly area.