敦煌阳关湿地芦苇叶片养分重吸收模式及其对土壤水分的响应  

Nutrient resorption patterns of Phragmites australis leaves and its response to soil moisture in Yangguan wetland,Dunhuang,Northwest China

作　　者：刘冬 张剑[1] 包雅兰 赵海燕 齐璇璇 谢欢杰 张静白 LIU Dong;ZHANG Jian;BAO Ya-lan;ZHAO Hai-yan;QI Xuan-xuan;XIE Huan-jie;ZHANG Jing-bai(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]西北师范大学地理与环境科学学院,兰州730070

出　　处：《应用生态学报》2020年第3期807-813,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41461012);甘肃省自然科学基金项目(1208RJAZ114)资助。

摘　　要：植物叶片的养分重吸收是养分贫瘠生境中植物重要的养分保存机制。研究叶片养分重吸收对土壤水分的响应,有助于了解植物对环境的适应策略。以敦煌阳关湿地优势植物芦苇为对象,研究不同水分条件[高:33.5%±1.9%、中:26.4%±1.3%、低:11.3%±1.5%]下芦苇叶片氮磷重吸收模式及其对土壤水分的响应。结果表明:1)随着土壤水分下降,土壤N浓度显著降低,芦苇成熟叶片及衰老叶片N浓度显著升高,成熟叶片和衰老叶片P浓度及土壤P浓度均无显著变化。2)高水分条件叶片N重吸收效率为76.1%,显著高于中(65.5%)、低(62.5%)水分条件;不同水分条件叶片P重吸收效率无显著差异。3)成熟叶片和衰老叶片N浓度与叶片N重吸收效率呈极显著负相关;成熟叶片P浓度与叶片P重吸收效率无显著相关性,而衰老叶片P浓度与叶片P重吸收效率呈极显著负相关。说明土壤水分缺乏不利于叶片N重吸收。Nutrient resorption of leaves is an important nutrient conservation mechanism for plants in nutrient-poor habitats.Understanding the responses of leaf nutrient resorption to soil moisture is helpful to reveal the adaptation strategies of plants to the environment.In this study,the dominant plant in the Yangguang wetland of Dunhuang Phragmites australis was used as research material,to explore nitrogen and phosphorus resorption patterns of P.australis leaves and their responses to soil moisture under different moisture regimes,i.e.high(33.5%±1.9%),medium(26.4%±1.3%)and low(11.3%±1.5%).The results showed that:1)With the decreases of soil moisture,soil N concentration decreased significantly,and N concentrations in mature and senescent leaves increased significantly,the P concentration in mature and senescent leaves as well as in soil did not change.2)N resorption efficiency of leaves under high moisture condition was 76.1%,which was significantly higher than the medium(65.5%)and low(62.5%)moisture conditions.P resorption efficiency varied among different moisture conditions.3)The N concentrations of mature and senescent leaves were negatively correlated with N resorption efficiency.There was no significant correlation between P concentration and P resorption efficiency in mature leaves,but the P concentration of senescent leaves was negatively correlated with P resorption efficiency of leaves.As a result,water scarcity is not conducive to leaf N resorption.

关 键 词：养分重吸收 芦苇叶片 水分梯度 敦煌阳关湿地 

分 类 号：S152.7[农业科学—土壤学] S564.2[农业科学—农业基础科学]