The object of this paper is the different plant communities in the Ejina desert riparian forest. Groundwater depth, soil moisture, plant water potential, relative leaf moisture content and water use efficiency was mon...The object of this paper is the different plant communities in the Ejina desert riparian forest. Groundwater depth, soil moisture, plant water potential, relative leaf moisture content and water use efficiency was monitored, and the response of soil moisture and plant ecology to the groundwater depth and the water use efficiency of the different plant communities was analyzed. The results showed that：（1） Along with the groundwater depth increasing, predawn and midday water potential of the plants, with the exception of Reaumuria soongorica, did not decrease significantly, indicating that when the groundwater depth is less than 3 m, the plant communities in the range of 4 km from the river way did not suffer or slightly suffer from water stress;（2） The distribution of higher soil moisture content within 0–3 m soil layer is suitable with the plants’ root system, as indicated in the communities of coexisting overripe Populus euphratica or Taramrix chinensis, both of which can release excessive water into soil for shallow rooted shrubs or herbaceous plants when there is water shortage;（3） R. soongorica can absorb deep soil moisture through deep roots for their own survival;（4） The community consisting of Sophora alopecuroides, Karelinia caspica, T. chinensis, and overripe P. euphratica has the best species combination for restoring the damaged eco-environment in the lower reaches of Heihe River;（5） The order of plants’ relative leaf water contents is K. caspica ＆gt; S. alopecuroides ＆gt; young P. euphratica ＆gt; overripe P. euphratica ＆gt; mature P. euphratica = T. chinensis coexisting with other species ＆gt; single R. soongorica ＆gt; single T. chinensis and the order of WUE is single T. chinensis ＆gt; single R. soongorica ＆gt; T. chinensis living in symbiosis with other species ＆gt; S. alopecuroides = young P. euphratica ＆gt; mature P. euphratica ＆gt; overripe P. euphratica ＆gt; K. caspica. Therefore, with ample soil moisture, the plant community helps rapid growth of T. chinensis, young P. euphratica and R. soongorica plants of less moisture content. Despite this they do not have much water storage capability, but have strong drought resistance, and higher moisture contents of S. alopecuroides and K. caspica, thus leaving them with poor drought resistance. Overall, the desert riparian forest plant community in the lower reaches of Heihe River helps the species of higher WUE live on it.展开更多
Soil moisture is the key resource constraint in arid ecosystems, and has been a focus of research on restoration. However, quantitative studies on the contribution of rainfall to deep soil rainfall infiltration are la...Soil moisture is the key resource constraint in arid ecosystems, and has been a focus of research on restoration. However, quantitative studies on the contribution of rainfall to deep soil rainfall infiltration are lacking. In this study, we used the YWB-01 Deep Soil Infiltration Water Recorder which had been invented by ourselves to measure the quantity of rain infiltration into deep soil, 150 cm below ground, in four locations in China: Mu Us Sandy Land and Ulan Buh, Tengger, and Badan Jilin deserts over a 2-year period. We found:(1) Deep soil rainfall infiltration decreased progressively from east to west and from semiarid to arid areas, with two locations completely lacking rainfall infiltration. Heavy rain was important to deep soil infiltration in shifting sandy land of arid and semiarid areas.(2) Seasonal variation of infiltration was correlated with rainfall, with a time lag that was less apparent in areas with more rainfall.(3) For single intense rainfall events, infiltration maximums occurred 40–55 h after the rainfall, during which the infiltration rates increased rapidly before reaching a peak, and then decreased slowly. Continuous infiltration could last about 150 h. Rainfall infiltration was determined by the combined action of intensity, quantity and duration. Rainfall with low intensity, long duration, and large quantity was most favorable for deep soil infiltration. Our results can be used in water resource assessments and protection during eco-restoration in the arid and semiarid areas in China.展开更多
基金supported financially by the National Natural Science Foundation of China(Grant No.91025025)National Basic Research Program of China(Grant.No.2010CB951003)
文摘The object of this paper is the different plant communities in the Ejina desert riparian forest. Groundwater depth, soil moisture, plant water potential, relative leaf moisture content and water use efficiency was monitored, and the response of soil moisture and plant ecology to the groundwater depth and the water use efficiency of the different plant communities was analyzed. The results showed that：（1） Along with the groundwater depth increasing, predawn and midday water potential of the plants, with the exception of Reaumuria soongorica, did not decrease significantly, indicating that when the groundwater depth is less than 3 m, the plant communities in the range of 4 km from the river way did not suffer or slightly suffer from water stress;（2） The distribution of higher soil moisture content within 0–3 m soil layer is suitable with the plants’ root system, as indicated in the communities of coexisting overripe Populus euphratica or Taramrix chinensis, both of which can release excessive water into soil for shallow rooted shrubs or herbaceous plants when there is water shortage;（3） R. soongorica can absorb deep soil moisture through deep roots for their own survival;（4） The community consisting of Sophora alopecuroides, Karelinia caspica, T. chinensis, and overripe P. euphratica has the best species combination for restoring the damaged eco-environment in the lower reaches of Heihe River;（5） The order of plants’ relative leaf water contents is K. caspica ＆gt; S. alopecuroides ＆gt; young P. euphratica ＆gt; overripe P. euphratica ＆gt; mature P. euphratica = T. chinensis coexisting with other species ＆gt; single R. soongorica ＆gt; single T. chinensis and the order of WUE is single T. chinensis ＆gt; single R. soongorica ＆gt; T. chinensis living in symbiosis with other species ＆gt; S. alopecuroides = young P. euphratica ＆gt; mature P. euphratica ＆gt; overripe P. euphratica ＆gt; K. caspica. Therefore, with ample soil moisture, the plant community helps rapid growth of T. chinensis, young P. euphratica and R. soongorica plants of less moisture content. Despite this they do not have much water storage capability, but have strong drought resistance, and higher moisture contents of S. alopecuroides and K. caspica, thus leaving them with poor drought resistance. Overall, the desert riparian forest plant community in the lower reaches of Heihe River helps the species of higher WUE live on it.
基金supported by the National Basic Research Program of China (Grant No. 2013CB429901)the National Natural Science Foundation of China (Grant Nos. 31170667 and 40971283)
文摘Soil moisture is the key resource constraint in arid ecosystems, and has been a focus of research on restoration. However, quantitative studies on the contribution of rainfall to deep soil rainfall infiltration are lacking. In this study, we used the YWB-01 Deep Soil Infiltration Water Recorder which had been invented by ourselves to measure the quantity of rain infiltration into deep soil, 150 cm below ground, in four locations in China: Mu Us Sandy Land and Ulan Buh, Tengger, and Badan Jilin deserts over a 2-year period. We found:(1) Deep soil rainfall infiltration decreased progressively from east to west and from semiarid to arid areas, with two locations completely lacking rainfall infiltration. Heavy rain was important to deep soil infiltration in shifting sandy land of arid and semiarid areas.(2) Seasonal variation of infiltration was correlated with rainfall, with a time lag that was less apparent in areas with more rainfall.(3) For single intense rainfall events, infiltration maximums occurred 40–55 h after the rainfall, during which the infiltration rates increased rapidly before reaching a peak, and then decreased slowly. Continuous infiltration could last about 150 h. Rainfall infiltration was determined by the combined action of intensity, quantity and duration. Rainfall with low intensity, long duration, and large quantity was most favorable for deep soil infiltration. Our results can be used in water resource assessments and protection during eco-restoration in the arid and semiarid areas in China.
