摘要
土壤水分是干旱区多尺度生态水文过程的关键影响因素和驱动因子,其时空格局是生态、水文、气象、地形等自然过程研究的重要参数。笔者研究了降水径流事件后3种不同灌丛个体尺度土壤水分空间异质性特征,结果表明,珍珠灌丛个体尺度土壤水分空间分布特征表现为灌丛边缘>灌丛内部>灌丛间裸地,驼绒藜灌丛表现为灌丛内部>灌丛边缘>灌丛间裸地,而狭叶锦鸡儿灌丛不同微生境土壤水分差异不显著。珍珠和驼绒藜灌丛同一微生境土壤水分存在坡位梯度,珍珠灌丛3个微生境土壤水分均表现为上坡位大于下坡位,而驼绒藜灌丛边缘表现为上坡位小于下坡位,其他两个微生境无明显规律;狭叶锦鸡儿灌丛土壤水分无明显的坡位梯度。3种灌丛不同微生境土壤含水量随土层深度增加的变化不明显。这说明在降水径流事件中,不同斑块的反应差异引起了地表径流的形成以及随之发生的资源再分配,从而导致了景观内土壤水分的空间异质性。
Soil moisture is a major control and driving factor on multi-scale ecohydrological processes,and is also a key parameter to many aspects of ecological,hydrological,meteorological and geomorphic research;it has high spatial and temporal variability in land-surface hydrologic systems.The patch-scale soil moisture at different soil depth in three microenvironments(inside the shrub,the margins of the shrub canopy and outside the shrub) of three species was investigated immediately after precipitation event,and results show that the spatial pattern of soil moisture at individual scale of Salsola passerina shrub is that soil moisture in the margin of the shrubinside the shruboutside the shrub,while the spatial pattern of Ceratoides latens shrub is that inside the shrubmargin of the shruboutside the shrub,and no significant differences are found among the three microenvironments of Caragana stenophylla shrubs.Slope gradient trend of soil moisture is found between the upslope and downslope in the same microenvironment under S.passerina and C.latens shrubs.Soil moisture at upslope of all the three microenvironments of the S.passerina shrub is greater than those at the downslope of the shrub,while soil moisture at upslope of the margin of C.latens shrub is less than that at the downslope of the shrub,and no remarkable slope gradient trend is found for the other two microenvironments of C.latens and for all three microenvironments of C.stenophylla shrub.No noticeable vertical soil moisture gradient trend is found in different microenvironments of these three shrubs.The investigation results of spatial pattern of soil moisture induced by runoff in patchy vegetation areas suggests that the differences in responses of different shrub patches to rainfall event lead to the generation of runoff and the induced resource redistribution,which results in the spatial heterogeneity of soil moisture in the landscape.
出处
《中国沙漠》
CSCD
北大核心
2012年第6期1576-1582,共7页
Journal of Desert Research
基金
国家自然科学基金项目(40701002
41171078)
中国科学院"西部之光"人才培养计划"西部博士资助项目"共同资助
关键词
地表径流
土壤水分
灌丛生境
空间异质性
腾格里沙漠
runoff
soil moisture
shrubland microenvironments
spatial heterogeneity
Tengger Desert