土石山区不同植物土壤水分利用方式对降雨的响应特征  

Response characteristics of soil water use patterns by different plants to precipitation in rocky mountainou areas

作　　者：张铁钢[1] 李占斌[1,2] 李鹏[1] 徐国策[1] 刘晓君[2] 靳宇蓉 

机构地区：[1]西安理工大学西北旱区生态水利工程国家重点实验室培育基地,西安710048 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《应用生态学报》2016年第5期1461-1467,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41330858;41401316;41271290)资助~~

摘　　要：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.Water-use characteristics of plants are important for vegetation restoration in shallow earth-rock mountain area. In this study, soil and plant samples of Platycladus orientalis and corn were collected after rainfall events in Yingwugou watershed of Dan River to analyze the signatures of oxygen isotopes and the response of water use patterns to precipitation using stable isotope technolo- gy. The results showed that there were different response characteristics of the soil water utilization to precipitation between P. orientalis and corn. The root of P. orientalis mainly used the soil moisture from 10-30 cm layer, while corn mainly used that in the depth of 0-20 era. The water absorption depth （WAP） of P. orientalis root decreased from 20-30 cm to 10-20 era, while that of corn altered from 10-20 cm to 0-20 cm, when precipitation decreased from 29 mm to 8 mm. The WAP of P. orientalis gradually changed from deep to shailow soil, while the main WAP of corn increased from 10-20 cm to 0-20 cm, when precipitation decreased. The response of P. orientalis and corn to precipitation was very obvious.

关 键 词：土石山区 退耕还林 氧同位素 水分来源 

分 类 号：S152.7[农业科学—土壤学]