氮沉降下西南亚高山针叶林生长的养分限制特征  

Nutrient limiting characteristics of subalpine coniferous forests under conditions of nitrogen deposition in the southwest mountains of China

作　　者：尹明珍 郭婉玑 朱晓敏 张子良[1,3] 刘庆 尹华军[1] YIN Mingzhen;GUO Wanji;ZHU Xiaomin;ZHANG Ziliang;LIU Qing;YIN Huajun(CAS Key Laboratory Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China;Clemson University,Clemson 29670,USA)

机构地区：[1]中国科学院成都生物研究所,中国科学院山地生态恢复与生物资源利用重点实验室,生态恢复与生物多样性保育四川省重点实验室,成都610041 [2]中国科学院大学,北京100049 [3]克莱姆森大学,克莱姆森29670

出　　处：《应用与环境生物学报》2021年第1期1-7,共7页Chinese Journal of Applied and Environmental Biology

基　　金：中国科学院前沿科学重点研究项目(QYZDB-SSW-SMC023);国家自然科学基金面上项目(31872700、31670449);四川省重点研发项目(2018SZ031);四川省重大科技专项(2018SZDZX0035)资助。

摘　　要：长期氮(N)沉降及其诱导的N、磷(P)养分平衡性对森林生长与生产力的生态反馈效应已成为当前森林生态学研究的前沿与热点,但目前大多研究主要基于已有文献数据整合分析,而缺乏野外原位系统性研究与试验证据.以西南亚高山两种典型人工针叶林——云杉(Picea asperata)林和华山松(Pinus armandii)林为对象,通过野外原位N添加模拟大气N沉降,从叶片养分状态和生理特征变化的角度研究N沉降下该区域树木生长的养分限制特征.结果表明:(1)N添加显著降低了两种人工林叶片P含量,导致云杉和华山松叶片N:P值分别比对照增加了9.9%和5.8%,表明N添加在一定程度上驱动了两种林分生长的P养分限制,且云杉林P养分受限程度更明显;(2)N添加显著降低了云杉林叶片NRE/PRE值,而对华山松林无显著影响,表明N添加下云杉人工林生长受到了明显的P养分限制;(3)N添加显著降低了两种人工林叶片各P组分含量,但显著提高了叶片酸性磷酸酶活性.因此,叶片养分状态和生理特征研究均表明N沉降导致亚高山森林树木生长受到不同程度的P养分限制,且云杉人工林P受限程度比华山松林更为明显,推测N沉降驱动的林分P受限程度可能与两种林分土壤养分初始状况有关;结果可为全球气候变化下森林的适应性管理提供重要科学依据.(图3表2参49)The effect of long-term nitrogen(N) deposition and the induced N-phosphorus(P) nutrient balance on the ecological feedback of forest growth and productivity has become a research focus. However, most of the current studies are based on data integration from the existing literature and there is a lack of systematic field research and related empirical evidence. In this study, two typical artificial subalpine coniferous forests in Southwest China, a Picea asperata plantation and a Pinus armandii plantation, were examined. By adding N in situ in the field to simulate atmospheric N deposition, the nutrient limiting characteristics of tree growth in this region under conditions of N deposition were verified by studying the leaf nutrient status and physiological characteristics. The results showed that:(1) the addition of N significantly decreased the foliar P concentration in the two plantations, resulting in an increase in foliar N:P ratio by 9.9% and 5.8% over the control in the P. asperata plantation and P. armandii plantation, respectively. This indicated that N addition drove P nutrient limitation in both plantations to a certain extent, and the degree of P nutrient limitation was more severe in the P. asperata plantation;(2) N addition significantly reduced the NRE/PRE ratio of P. asperata leaves, but had no significant effect on P. armandii leaves. The results showed that the growth of P. asperata plantations in response to N addition was significantly restricted by P;(3) N addition significantly reduced the concentration of foliar P fractions, and markedly increased the foliar acid phosphatase activity in both plantations. Collectively, based on the interpretation of the leaf nutrient status and physiological characteristics, this study showed that N deposition induced P nutrient limitation to the growth of subalpine forest trees to different degrees, and that the degree of P nutrient limitation was more severe in the P. asperata plantation. We speculated that the P nutrient limitation degree of the stand driv

关 键 词：养分限制 N:P化学计量 亚高山针叶林 N沉降 

分 类 号：S718.5[农业科学—林学]