黄土丘陵沟壑区不同群落类型对土壤特性及生物量的影响  

Effects of Different Vegetation Types on Soil Characteristics and Plant Biomass in the Loess Hilly Region

作　　者：何亚龙[1] 李刚[2] 龙凌云[2] 李红[3] 龚春梅[2] 梁宗锁[2] 胡景江[2] 罗志斌[1,2] 

机构地区：[1]西北农林科技大学林学院,陕西杨陵712100 [2]西北农林科技大学生命科学学院,陕西杨陵712100 [3]西北农林科技大学植物保护学院,陕西杨陵712100

出　　处：《西北林学院学报》2011年第6期1-7,共7页Journal of Northwest Forestry University

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-YW-443);教育部新世纪优秀人才支持计划(NCET-08-0468);西北农林科技大学人才基金项目

摘　　要：以农田为对照,分析了退耕还林还草过程中所形成的植物群落对退耕地土壤水分、有机碳、氮、磷、钾含量的影响及其垂直分布特征和退耕地植物的生物量变化。结果表明:不同群落类型中,0～100cm土层的土壤含水量为6.9%～14.1%,撂荒地和苜蓿地土壤含水量随土壤深度的增加呈增加趋势,而柠条林地随土壤深度的增加呈下降趋势;0～20cm表层土壤中,有机碳、碳密度和全氮含量较20～100cm变化大;在0～100cm土层,与农田、撂荒地和苜蓿地相比,沙棘和柠条土壤全磷含量显著降低;不同退耕地植物生物量(地上和地下)差异显著,呈现柠条>沙棘>苜蓿>撂荒地>农田的变化趋势。表明退耕过程中草本的恢复对保持土壤深层水分含量有促进作用,而灌木的恢复对保持和增加土壤表层养分有较强的促进作用。To investigate the influences of vegetation types on soil moisture, nutrients and biomass, soil water content, organic carbon, total nitrogen, potassium, phosphorus and plant biomass were analyzed under different vegetation types in the Loess hilly region in China. Soil water contents in 0-100 cm layer varied from 6.9% to 14. 1%. In abandoned land and land covered with Medicago sativa, the moisture increased with the increase of soil depths, but in land covered with Caragana korshinskii it displayed an opposite trend. In 0--20 cm top soil layer, organic carbon and total nitrogen in land covered with different vegetation types showed significant changes in comparison with those in arable land. Phosphorus contents were lower in 0--100 cm layer in land covered with Hippophae rhamnoides and Caragana korshinskii compared to those in arable land. In 0-100 cm layer, soil potassium contents displayed gradual decreases in Medicago sativa, abandoned, arable, Hippophae rharnnoides and Caragana korshinskii lands. Positive linear correlations existed between soil organic carbon and total nitrogen across different vegetation types. Soil carbon to nitrogen ratios increased with the land use changes from arable to lands covered with grasses and shrubs, which indicates soils from grass and shrub lands contained more organic carbon and nitrogen in comparison with that from arable land. Plant biomass showed gradual increases in arable, abandoned,Medicago sativa, Hippophae rhamnoides and Caragana korshinskii lands. These results indicate that herbaceous vegetation restoration promotes water moisture in deep soil and woody vegetation enhances nu- trients in top soil.

关 键 词：黄土丘陵沟壑区 植被类型 土壤养分 土壤水分 生物量 

分 类 号：S728.2[农业科学—林木遗传育种] S714.2[农业科学—林学]