陕北黄土区陡坡地人工植被的土壤水分生态环境  

Soil moisture ecological environment of artificial vegetations in steep slope of loess region in North Shaanxi Province

作　　者：王延平[1] 邵明安[2] 张兴昌[2] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]中国科学院水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100

出　　处：《生态学报》2008年第8期3769-3778,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金重大研究计划资助项目(90502006);西北农林科技大学"创新团队"资助项目;陕西省科技攻关资助项目(2005K01-G14-03)~~

摘　　要：通过定点土壤水分测定与对比分析，研究了陕北黄土区35～45°陡坡地人工植被的土壤水分亏缺状况、年际、年内动态变化规律、干燥化特征及其补偿恢复特征。结果表明：陡坡地多年生人工植被的土壤水分亏缺极为严重，贫水年0～10m土层贮水量仅相当于田间持水量的26．2％～42．0％，丰水年贮水量也仅占田间持水量的27．0％～43．3％；亏缺次序为：柠条〉刺槐〉苜蓿〉侧柏〉杨树〉油松〉荒坡〉杏〉枣〉农地。年际间同一植被土壤水分含量的变化主要发生在200cm以上土层内，变异程度随土壤深度的增加而减弱。同一生长季，各种植被0～120cm土层含水量的变异系数都较大，但植被间差异较小；120cm以下土层，变异系数较小，但植被间差异较大。陡坡地多年生植被均有永久干层存在，但深层土壤干燥化强度因植物种类和生长年限而存在明显的差异。雨季土壤水分的补偿和恢复深度为1．0～1．4m，但不同植被的土壤贮水增量和补偿度有较大差异。同一植被丰水年的雨水补偿深度比干旱年可增加60cm以上，5m土层贮水增量增加3倍以上。在自然降雨条件下，陡坡地多年生人工植被的土壤贮水亏缺状况不能得到改善，土壤干化现象也不可能有所缓解。By means of located monitoring and comparatively analysis, soil water deficient situation, soil moisture dynamic variation laws, soil aridizations and soil water compensation features under condition of different artificial vegetations have been studied in 35 --45°steep slope of loess region in North Shaanxi. The results showed that： soil water was extremely deficient under condition of perennial artificial vegetations in steep slope, soil water storage （0 --10m） was only equal to 26.2%--42.0% of field capacity in dry years, and in rainy years it was also only equal to 27.0%--43.3% of field capacity. The order of soil water deficit was： Caragana microphylla 〉 locust 〉 alfalfa 〉 Chinese arbor-vitae 〉 poplar 〉 Chinese pine 〉 wild land 〉 apricot 〉 Chinese date 〉 farm land. Annual variations of soil moisture with same vegetation were weakened with soil depth increasing, and happened mainly in 0 --200 cm soil layers. In same growth season, all CV （ Coefficient of Variation） of soil moisture under different vegetations were bigger and concentrated comparatively in 0 -- 120 cm soil layers, but difference of CV in different vegetations was small; below 120 cm soil layers, CV were smaller, but difference of CV in different vegetations was bigger. Permanent soil dry layers always happened under condition of perennial vegetations in steep slope, but the difference of soil aridization intensity was obvious among different vegetations and growth years. Soil water compensation and recovery depths in rainy season were 1.0 - 1.4 m, but the soil water storage increment and compensation degree in different vegetations were dramatically different. Soil water compensation depth in same vegetation in rainy years was increased over 60 cm than in dry years, while the soil water storage increment in 5 m soil layers was increased over 3 times. Under natural precipitation, the soil water deficit in artificial vegetations in steep slope cannot be reduced, soil aridization also cant be relieved.

关 键 词：陕北黄土区 陡坡地 多年生人工植被 土壤水分生态环境 

分 类 号：S152.75[农业科学—土壤学]