河西绿洲荒漠过渡带梭梭林土壤保育效应  

Soil Conservation Effect of Haloxylon Ammodendron Bushes in Hexi OasisDesert Ecotone

作　　者：王彦武 罗玲[2] 张峰 陈天林[3] WANG Yanwu;LUO Ling;ZHANG Feng;CHEN Tianlin(Gansu Institute of Soil and Water Conservation Sciences, Lanzhou 730020, China;College of Resource and Environment, Henan Polytechnic University, Jiaozuo, Henan 454000, China;Soil and Water Conservation Bureau, Department of Water Resources of Gansu Province, Lanzhou 730000, China)

机构地区：[1]甘肃省水土保持科学研究所,兰州730020 [2]河南理工大学资源环境学院,河南焦作454000 [3]甘肃省水利厅水土保持局,兰州730000

出　　处：《土壤学报》2019年第3期749-762,共14页Acta Pedologica Sinica

基　　金：甘肃省青年科技基金项目(1506RJYA177);甘肃省自然科学基金项目(1308RJZA237)资助~~

摘　　要：研究不同龄阶梭梭林对土壤的保护效应和复育效应的变化特征,探讨各因子之间的相互关系和梭梭林保育土壤的内在机制,可为治理河西绿洲荒漠过渡带梭梭林的土壤质量提供理论基础。在民勤绿洲荒漠过渡带采用典型抽样和空间代替时间的方法,以不同龄阶的梭梭林(20a、30a、40a)和裸沙地为研究对象,定期监测其防风固沙作用和土壤机械组成、化学性质、微生物数量及土壤酶活性变化特征,并分析了各因子的变化规律和相关关系。结果表明:梭梭林保护土壤的效应取决于梭梭林的生长情况及树龄,距离梭梭植株越近,风速逐渐减小,且背风面的减小程度大于迎风面;梭梭林中下部对风速的阻碍作用大,风速降低幅度为顶端处的1.05倍~2.04倍;随着梭梭林龄的增长,风速降低幅度的均值由12.66%增大至20.41%。各龄阶梭梭林土壤粉粒和黏粒所占比例远远小于粗砂粒和细砂粒,随土层深度增加,粉粒和黏粒含量略有减小,但均显著大于裸沙地;随着树龄增加,土壤黏粒和粉粒含量增大,粗砂粒含量减小,分别在30年时出现峰值和谷值。各龄阶梭梭林土壤的养分含量、微生物数量和酶活性各指标均表现为30年生梭梭林>40年生梭梭林>20年生梭梭林,且均为裸沙地的1.02倍以上。梭梭林土壤保育效应因子、土壤机械组成、土壤养分、微生物数量和酶活性之间均有较好的相关性,梭梭林的风速降低程度与土壤的机械组成呈极显著相关,相关系数达到了0.87以上。从梭梭林保护土壤和改良土壤效应两方面综合考虑,30年生梭梭林更适合当地生境条件,其土壤保育效果最好。【Objective】In fragile ecosystems of the arid regions, soil revegetation effect is closely related to soil conservation effect. Haloxylon ammodendron forest play a quite important role in soil quality evolution in oasis-desert ecozones by protecting and ameliorating the soil. Especially its wind-breaking and sand-fixing effects and its generation of litter, which decomposes and transforms into organic matter and soil nutrients, are the most direct external environmental factors that affect soil quality evolution the most significantly. To explore soil conserving and restoring effects of Haloxylon ammodendron forests, affecting factors of the effects and relationships between the factors, and internal mechanism of the effects, stands of Haloxylon ammodendron forest different in age were selected for the study in an attempt to provide a theoretical basis for management of soil quality in the Hexi Oasis-desert Ecotone.【Method】The paper adopted the concept of space as a substitute for time in typical sampling in the ecozone. Three stands of Haloxylon ammodendron forest different in age(20 a, 30 a and 40 a) and a tract of bare land were set for long-term monitoring and soil sampling for analysis of soil mechanical composition, chemical properties, microbial population and enzyme activity, and multiple comparisons, variance analysis and correlation analysis were used to analyze variation rules and relationships between the factors.【Result】Results show that soil protecting effects of the forest varied with growth and age of the forest. Wind decreased gradually in speed when approaching the forest. The effect was more obvious at the lee side than at the windward side. At the height of 20 cm, 50 cm, 100 cm and 200 cm above the ground in the forest wind speed decreased by 13.75%, 14.55%, 15.0% and 7.34% or more, respectively. Obviously the wind reducing effect is higher in the middle and lower part of the forests than in the upper part, and about 1.05~2.04 times of that at the top of the plants. With the forest

关 键 词：绿洲荒漠过渡带 梭梭林 土壤保育 复育效应 保护效应 

分 类 号：S157.5[农业科学—土壤学]