内蒙古多伦县4种植被对沙地土壤的修复效应

摘要

To explore effects of vegetation restoration on soil properties in sandy land,soil samples were collected,separately,from 4 plots of land under Prunus sibirica (SX),Caragana korshinskii (NT),Salix gordejevii (HL),and natural grasses (CD) in Duolun County in Inner Mongolia for analysis of soil physical and chemical properties,such as content of soil water,pH,EC,SOC,total N,total P.Results show:(1) SOC is always the highest in the surface layer,regardless of plots,reaching 21.3,11.0,7.3 and 2.0 g · kg-1 in Plots SX,CD,NT and HL,respectively;(2) Total P,total N and SOC varied similarly in content;(3) The content of soil fine clay in Plot SX is the highest,reaching 26.5％,that in Plot CD,the second,being 10.8％,and that in Plot HL the least,being just 6.5％;(4) In the 0-10 cm soil layer,SOC is significantly or ultra-significantly related to TN,TP and soil water in content,and the content of fine clay is almost significantly related to all soil nutrient indices (P＜0.05 or P＜0.01).All the findings in this research demonstrate that,large-scale cultivation of Salix gordejevii in recent years is not ideal in improving physical and chemical properties of the sandy soil in the studied region,however,naturally developed grasslands have much better effect.Therefore,it is wise to pay more attention to protection of natural grasslands,when trying to control desertification by revegetation.%为揭示逆沙漠化进程中人工植被对沙地土壤的修复效应,选择内蒙古多伦县治沙园区的山杏(Prunus sibirica,SX)、柠条锦鸡儿(Caragana korshinskii,NT)和黄柳(Salix gordejevii,HL)3种人工植被群落和天然草地(CD)群落,对其土壤理化特性进行研究.结果显示:(1)各样地有机碳含量以表层为最高,SX、CD、NT和HL样地分别为21.3、11.0、7.3和2.0 g·kg-1;(2)土壤全氮、全磷和有机碳含量具有基本一致的变化规律;(3)土壤细黏粒(＜20 μm)含量以SX样地为最高,达到26.5％,CD样地次之,为10.8％,HL样地最低,仅为6.5％;(4)0～10cm土层全磷含量、全氮含量、含水量与有机碳含量之间呈显著或极显著正相关关系(P＜O.05或P＜0.01),特别是土壤细黏粒含量,几乎与所有土壤养分指标间呈显著相关性.该研究表明,近年来大面积种植的黄柳人工群落对于土壤理化特性的改善效果不显著,而自然发展的草地群落改善效果明显,因此,当地在大量实施人工植被治沙的同时更应注重保护天然草地植被.