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植物的水分利用特征对浅层土石山区的植被恢复具有重要意义.本研究利用稳定同位素技术,通过采集降雨后丹江鹦鹉沟小流域侧柏和玉米的植物样及其植物根系周围的土壤样品,分析其氧稳定同位素特征,研究土石山区侧柏和玉米两种不同植物的土壤水分利用方式对降雨的响应特征.结果表明:侧柏和玉米的土壤水分利用方式对降雨存在不同的响应特征.侧柏根系主要利用10~30 cm土层的土壤水分,而玉米主要利用0~20 cm土层的土壤水分.降雨量由29 mm减少至8 mm时,侧柏根系的主要吸水深度由20~30 cm减小到10~20cm,玉米根系的主要吸水深度由10~20 cm转换为0~20 cm.降雨减少时,侧柏根系吸水的主要深度均由深层土壤向浅层土壤移动,而玉米的主要吸水深度由10~20 cm增加为0~20 cm.侧柏和玉米根系的土壤水分利用方式对降雨的响应特征较为明显.
The characteristics of plant water use are of great importance to vegetation restoration in shallow soil and mountainous areas.Using stable isotope techniques, the plant samples and the soil samples around the plant roots of the Piedmont, The characteristics of oxygen stable isotopes were analyzed to study the response characteristics of soil water use under different rainfall regimes to the different plant species of Platycladus orientalis and Maize in mountainous areas of China. The results showed that there were different response characteristics to the rainfall. The main use of bermudagrass was soil moisture in 10 ~ 30 cm soil layer, while that in maize mainly used soil moisture in 0 ~ 20 cm soil layer.When the rainfall decreased from 29 mm to 8 mm, the main water absorption depth of Platycladus orientalis roots ranged from 20 to 30 cm to 10-20 cm, and the main water-absorbing depth of maize root system was changed from 10-20 cm to 0-20 cm. The main water absorption of P. orientalis water moved from deep soil to shallow soil when the rainfall decreased, while that of maize The main water-absorbing depth increased from 10 to 20 cm to 0 to 20 cm, and the response characteristics of soil water use patterns of Arborvitae and maize roots to rainfall were obvious.