摘要
水分承载力是干旱半干旱区植被重建的重大科学问题之一。在9、16、26年生人工柠条林和天然草地（对照）各选择3个重复样地,在其中1个样地中心埋设300 cm深的土壤水分探管,从2012年4月15日—11月15日,用德国IMKO公司生产的TRIME/T3型TDR按每20 cm分层每半月测定一次;基于研究区人工柠条林土壤水分动态周年监测得出的土壤水分变化时间节点,分别在2012年4月底、8月底、10月初、次年3月初和4月底,采用土钻-烘干法对9、16、26年生人工柠条林和天然草地（对照）3个重复样地0～200 cm土壤水分进行监测。结果表明：（1）人工柠条林和草地的土壤水分的周年节律相同,5—8月为严重失水期,9月是蓄水期,10月至次年2月属于微弱失水期,3—4月失水量开始加速。（2）草地与人工柠条林之间的土壤水分差异并不显著,人工柠条林各林龄之间的土壤水分差异显著。（3）各种植被的土壤水分周年闭合差均出现亏缺。26年生柠条林的土壤水分亏缺最小,反映了其自我调整、适应环境、寻求新平衡的过程。（4）荒漠草原区土壤水分主要受降水分配、土壤性状等环境因子和植物根系分布显著影响,环境因子在土壤水分中的主导作用更明显。
Caragana shrub has been widely planted to prevent ecological deteriratin in desert steppe. However, water capacity is the most important factor limiting the development of Caraga- na in this area. Annual variations of soil moisture in Caragana stands with different ages （9, 16 and 26 years old） and natural grassland in April, August, October in 2012 and March, April in 2013 were studied. The results showed that： （1） Similar soil moisture dynamic pattern was observed in the different Caragana stands in an annual cycle. Soil moisture was dramatically deple- ted from May to August and recovered in September. Soil water underwent slight depletion from October in 2012 to February in 2013. The depleting process of soil moisture was accelerated from March to April. （2） There was no significant difference in soil moisture between grassland and Caragana stands, while a significant difference in soil moisture was found between the Caragana stands with different ages. （3） The annual closure errors of soil moisture for the different Cara- gana stands were under deficit. The least soil water deficit was recorded for the 26-year-old Ca- ragana stand, indicating its low water consumption and strong ability to keep soil water balance. （4） The precipitation distribution, soil texture and rooting character had profound effects on the soil moisture in desert steppe.
出处
《生态学杂志》
CAS
CSCD
北大核心
2014年第10期2618-2624,共7页
Chinese Journal of Ecology
基金
国家重点基础研究发展计划前期专项(2012CB723206)
国家科技支撑计划项目(2011BAC07B03)资助
