摘要
通过测定不同地下水埋深下胡杨和柽柳的幼苗茎干水和各潜在水源(土壤水、地下水)的δD和δ18 O同位素组成特征,利用IsoSource模型和平均深度模型,研究了胡杨和柽柳的幼苗对各潜在水源的利用比例和根系吸水的平均土壤深度。结果表明,单一种植条件下胡杨和柽柳的幼苗具有相似的水分利用特征,在30,80cm地下水埋深下深层土壤水和地下水是其主要水分来源,利用比例超过80%;在130,180cm地下水埋深下浅层土壤水为其主要水源,直接利用地下水的比例很小;在180cm埋深时胡杨幼苗不能直接利用地下水,对0—80cm土壤水的利用比例高达79.9%,柽柳幼苗利用地下水的比例仅为12.9%,对0—80cm土壤水的利用比例达到62%;混合种植下对水分的竞争作用使柽柳幼苗主要利用深层土壤水和地下水,胡杨幼苗主要利用浅层土壤水;柽柳幼苗利用水分的平均深度显著深于胡杨幼苗,表明柽柳对干旱环境的适应能力优于胡杨。
In order to investigate the water uptake of seedlings of Populus euphratica and Tamarix ramosissima along the depth of groundwater,apot experiment with 4different groundwater depth（30cm,80 cm,130cm and 180cm）treatments was conducted to study the probable contributions of potential water sources to total plant water uptake and the mean soil depth of water uptake by seedlings of Populus euphraticaand Tamarix ramosissima,through measuring theδD andδ18 O compositions of the stem water and potential water sources（soil water and groundwater）of seedlings and using the IsoSource model and the model of the mean depth of plant water uptake.The results showed that the rate of water uptake was similar for Populus euphraticaand Tamarix ramosissimaseedlings when the 2plant species were cultivated alone.When the groundwater levels were 30 cm and 80 cm,deep soil water and groundwater were the main water sources of Populus euphratica and Tamarix ramosissima seedlings,with the utilization proportion exceeding 80%.When the groundwater levels were 130 cm and 180 cm,Populus euphraticaand Tamarix ramosissimaseedlings started to use shallow soil water primarily and the utilization proportion of groundwater was very low for the 2plant species.Populus euphratica seedlings could not use groundwater directly when the groundwater level was 180 cm,and obtained79.9% of its water from the 0—80cm soil layer.Tamarix ramosissima seedlings obtained 12.9% and 62% of its water from groundwater and the 0—80cm soil layer,respectively.When Populus euphraticaseedlings and Tamarix ramosissimaseedlings were planted together,their water-use strategies were changed due to the competition for water.Tamarix ramosissima seedlings mainly used deep soil water and groundwater,while Populus euphratica seedlings mainly used shallow soil water.These results suggested that Tamarix ramosissima was much easier to adapt the drought environment than Populus euphraticain the arid region.
出处
《水土保持学报》
CSCD
北大核心
2015年第4期241-246,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(41171095)
重大科学研究计划项目"973"(2013CB429905)
国家科技支撑计划项目(2013BAC10B01)
关键词
地下水
稳定同位素
水分来源
胡杨幼苗
柽柳幼苗
groundwater
stable isotopes
water sources
Populus euphratica seedling
Tamarix ramosissima seedling
