不同林龄刺槐叶片养分重吸收特征及其对土壤养分有效性的响应  

Leaf nutrient resorption characteristics of Robinia pseudoacacia at different ages and their response to soil nutrient availability

作　　者：许淼平 张欣怡 李文杰 任成杰 杨改河[1] 韩新辉[1] XU Miao-ping;ZHANG Xin-yi;LI Wen-jie;REN Cheng-jie;YANG Gai-he;HAN Xin-hui(College of Agronomy,Northwest A&F University/Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学农学院/陕西省循环农业工程技术研究中心,陕西杨凌712100

出　　处：《应用生态学报》2020年第10期3357-3364,共8页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2017YFC0504601)资助。

摘　　要：为揭示丘陵沟壑区刺槐的养分重吸收特征及其驱动因素,研究该区不同林龄刺槐叶片全氮和全磷的浓度,以及土壤有机碳、全氮、全磷、铵态氮、硝态氮和速效磷浓度及其化学计量,分析了叶片氮磷重吸收效率与土壤养分特性之间的关系。结果表明:植物和土壤的养分随林龄增长发生显著变化,而土壤总磷和速效磷浓度较低。氮重吸收效率随林分生长先增加后降低,范围为48.2%~54.0%,平均为48.5%;磷重吸收效率则显著增加,范围为45.2%~49.4%,平均为46.9%。氮重吸收效率与土壤氮素和氮磷比呈负向响应,而磷重吸收效率与氮磷比呈显著正相关,与土壤速效磷呈负相关。表明土壤养分有效性的变化负向驱动养分重吸收效率。由于该生境中刺槐林的固氮效应及磷限制,叶片养分重吸收策略对土壤氮磷比响应强烈。To reveal nutrient resorption characteristics of Robinia pseudoacacia and their driving factors in hilly and gully regions,we measured the concentration of total nitrogen and total phosphorus in leaves and the concentrations and stoichiometry of organic carbon,total nitrogen,total phospho-rus,ammonium,nitrate and available phosphorus in soils of R.pseudoacacia plantations with different stand ages.We analyzed the relationship between leaf nitrogen and phosphorus resorption efficiencies and soil nutrient characteristics.The nutrients in plants and soil changed significantly with stand ages.The total and available phosphorus concentrations were low in the soil.Nitrogen resorption efficiency first increased and then decreased with the increases of stand age,with a range of 48.2%-54.0%and a mean value of 48.5%.Phosphorus resorption efficiency increased significantly with stand age,with a range of 45.2%-49.4%and a mean value of 46.9%.Nitrogen resorption efficiency showed negative response to soil nitrogen and N:P.Phosphorus resorption efficiency was significantly positively correlated to soil N:P and negatively correlated to soil available phosphorus.Our results indicated that soil nutrient availability negatively drove nutrient resorption efficiency.The strategies of leaf nutrient resorption responded strongly to soil N:P due to the N2-fixing effect and P-limitation of R.pseudoacacia.

关 键 词：刺槐 养分重吸收 土壤养分有效性 化学计量 养分限制 

分 类 号：S792.27[农业科学—林木遗传育种] S714.8[农业科学—林学]