Spatial and temporal variability of soil water in drylands:plant water potential as a diagnostic tool  

作　　者：Maik VESTE Markus STAUDINGER Manfred KüPPERS 

机构地区：[1]Research Center for Landscape Development and Mining Landscapes,Brandenburg University of Technology,Cottbus D-03046,Germany Institute of Botany and Botanical Garden,University of Hohenheim,Stuttgart D-70599,Germany [2]AVL-ARGE Vegetation Ecology and Landscape Planing GmbH,Wien A-1060,Austria [3]Institute of Botany and Botanical Garden,University of Hohenheim,Stuttgart D-70599,Germany

出　　处：《Forestry Studies in China》2008年第2期74-80,共7页中国林学（英文版）

摘　　要：Arid and semi-arid regions are characterized by low rainfall and high potential evaporative demand. Here, water is the major limiting factor for plant growth and productivity. Soil and surface hydrology properties （e.g. field capacity, infikration rates） effectively control the water re-distribution in the ecosystem, a fact that is aggravated in arid environments. Information of the spatial and temporal accessibility of soil water in desert ecosystems is limited. The purpose of the studies is the application of plant water potential to estimate the spatial and temporal variations of soil water availability in different arid ecosystems of the Negev （Israel） and southern Morocco. As model plants the evergreen shrubs Retama raetam, Thymelaea hirsuta and trees （Acacia tortilis） were chosen. Seasonal and spatial variations of the pre-dawn water potential （ψpd） were examined as diagnostic tool to determine water availability on the landscape level. The seasonal differences in the pre-dawn water potential were less pronounced on the dune compared to the interdune. This showed a better water availability on the dune slope. Also in the investigated wadis systems spatial differences of the water potential could be detected and related to the vegetation pattern.Arid and semi-arid regions are characterized by low rainfall and high potential evaporative demand. Here, water is the major limiting factor for plant growth and productivity. Soil and surface hydrology properties （e.g. field capacity, infikration rates） effectively control the water re-distribution in the ecosystem, a fact that is aggravated in arid environments. Information of the spatial and temporal accessibility of soil water in desert ecosystems is limited. The purpose of the studies is the application of plant water potential to estimate the spatial and temporal variations of soil water availability in different arid ecosystems of the Negev （Israel） and southern Morocco. As model plants the evergreen shrubs Retama raetam, Thymelaea hirsuta and trees （Acacia tortilis） were chosen. Seasonal and spatial variations of the pre-dawn water potential （ψpd） were examined as diagnostic tool to determine water availability on the landscape level. The seasonal differences in the pre-dawn water potential were less pronounced on the dune compared to the interdune. This showed a better water availability on the dune slope. Also in the investigated wadis systems spatial differences of the water potential could be detected and related to the vegetation pattern.

关 键 词：soil water PATTERN predawn potential deserts Nizzana NEGEV 

分 类 号：S152.7[农业科学—土壤学]