摘要
为研究黄土区人工植被建设对深层土壤水分亏缺的影响,以晋西黄土区4种典型人工植被类型(苜蓿、刺槐、侧柏和核桃)和农地(对照)为研究对象,分析深剖面(70～500 cm)土壤储水量和细根生物量的变化规律及其相互关系。结果表明:1)深层土壤含水量的分布可划分为降水入渗层(70～160 cm)、过渡层(160～280 cm)和相对稳定层(280～500 cm); 2)不同人工植被类型土壤储水量在深层有显著性差异(P <0. 05),与农地相比,其他4种人工植被深层(> 70 cm)土壤储水量的总亏缺量为161. 94～448. 25 mm,并且苜蓿和侧柏水分亏缺深度达到3 m以上,刺槐和核桃则达到5 m以上; 3)深层(> 160 cm)细根生物量与土壤储水量具有显著的负相关关系(P <0. 05),刺槐和核桃深层细根生物量比例高于侧柏和苜蓿。研究区不同人工植被类型已产生明显的深层土壤水分亏缺问题,这与植被细根生物量剖面分布有紧密关系,该区域未来人工植被建设中应重点考虑刺槐和核桃根系特性与水分条件的适应性。
[Background]The Loess Plateau of western Shanxi is one of China’s most degraded land regions with serious soil erosion. Since the Grain-for-Green Program was implemented in this region,a growing number of exotic trees have been introduced by human activities. Due to their strong water consumption via deep roots,the contradiction between vegetation water demand and soil water supply has become increasingly prominent. Currently,there is a lack of research linking the characteristics of deep( > 2 m) soil moisture storage( SMS) and fine root distribution in the Plateau. This study analyzed the distribution of SMS and fine root biomass( FRB),and assessed their relationship under typical artificial vegetation types during the growing season in western Shanxi of the Loess Plateau. [Methods] Four artificial vegetation types( Medicago sativa,Robinia pseudoacacia,Platycladus orientalis,and Juglans regia) were selected from the study region,with long-term cropland as the control. Soil and root samples were taken from depths of 0-500 cm at 10 or 20 cm intervals. SMS was derived from soil moisture content that was measured based on oven-drying at 105-110 ℃,while FRB( < 2 mm) was measured after drying at 80 ℃ to constant weight. Differences among the treatments in deep layers were examined for SMS and FRB by one-way analysis of variance. The relationship between SMS and FRB in each deep layer was analyzed using Pearson’s correlation coefficients. [Results] Based on the distribution of soil moisture content,the soil profile was divided into 2 layers of shallow( 0-70 cm) and deep( 70-500 cm);the latter was subdivided into precipitation infiltration layer( 70-160 cm),transition layer( 160-280 cm),and relatively stable layer( 280-500 cm). The SMS in deep layers significantly differed among the 5 treatments( P < 0. 05). Compared with the control,the total deficit of SMS in deep soil profile under artificial vegetation types ranked as R. pseudoacacia(-448. 25 mm) > J. regia(-357. 6 mm) > M. sativa(-170. 83 mm) > P. orientalis(-161. 93 mm). There were significant negative correlations between FRB and SMS in the infiltration and stable layers( P < 0. 05). The FRB in deep soil profile of all 5 treatments accounted for approximately 37% of the FRB in the total soil profile.The average FRB in deep soil profile decreased in the order P. orientalis( 2. 9 g/m2) > R. pseudoacacia( 2. 68 g/m2) > J. regia( 2. 67 g/m2) > M. sativa( 1. 67 g/m2) > control( 0. 56 g/m2).[Conclusions]Deep soil moisture was depleted by artificial vegetation and this was closely related to the distribution of FRB in the deep soil profile. The strong linkage between local moisture conditions in the soil and water consumption by plant roots( especially R. pseudoacacia and J. regia) should be considered during the construction of artificial vegetation in the semi-arid Loess Plateau region.
作者
刘新春
赵勇钢
刘小芳
朱兴菲
高冉
栗文玉
LIU Xinchun;ZHAO Yonggang;LIU Xiaofang;ZHU Xingfei;GAO Ran;LI Wenyu(School of Life Science,Shanxi Normal University,041000,Linfen,Shanxi,China)
出处
《中国水土保持科学》
CSCD
北大核心
2019年第1期95-101,共7页
Science of Soil and Water Conservation
基金
山西省自然科学基金"晋西黄土区植被自然恢复土壤有机碳固定与稳定性机制"(201601D021103)
国家自然科学基金"草地演替中土壤结构演变与降雨-入渗过程的互作机理"(41401242)
关键词
人工植被
土壤储水量
细根生物量
晋西黄土区
artificial vegetation
soil moisture storage
fine root biomass
the Loess Plateau in western Shanxi
