三峡库区澎溪河消落带典型草本植物养分及生态化学计量特征  

Ecological Stoichiometry of the Representative Herbaceous Plants in the Littoral Zone of Pengxi River in Three Gorges Reservoir

作　　者：孔维苇 袁兴中 卢虹宇 陈稀 刘婷婷 龚小杰 王晓锋 KONG Weiwei;YUAN Xingzhong;LU Hongyu;CHEN Xi;LIU Tingting;GONG Xiaojie;WANG Xiaofeng(College of Geography and Tourism,Chongqing Normal University,Chongqing 401331;Chongqing Key L.aboratory of Wetland Science Research of the Upper Reaches of the Yangtze River,Chongqing 401331;Observation and Rescarch Station for the Earth Surface Ecological Processes of Three Gorges Reservoir Area,Kaizhou Chongqing 405400;Shanghai Environmental School,Shanghai 200135,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆401331 [2]长江上游湿地科学研究重庆市重点实验室,重庆401331 [3]三峡库区地表生态过程野外科学观测研究站,重庆开州405400 [4]上海市环境学校,上海200135

出　　处：《重庆师范大学学报（自然科学版）》2020年第5期73-82,共10页Journal of Chongqing Normal University:Natural Science

基　　金：国家自然科学基金(No.41807321);重庆市基础研究与前沿探索项目(No.cstc2018jcyjAX0672);重庆市教育委员会科学技术研究项目(No.KJQN201800530);重庆师范大学博士科研启动项目(No.17XLB023)。

摘　　要：【目的】探究消落带植物的养分利用、养分分配特征以及水位梯度下不同植物的适应策略,为水库消落带植被恢复和生态重建提供科学依据。【方法】以三峡库区澎溪河白家溪消落带不同水位梯度的狗牙根(Cynodon dactylon)、狼杷草(Bidens tripartita)、苍耳(Xanthium sibiricum)、苘麻(Abutilon theophrasti)等4种典型草本植物为研究对象,测定植物根、茎、叶中C,N,P和K的含量,并计算化学计量比,比较不同植物养分利用及分配策略,探讨不同水位梯度下植物生态化学计量特征的响应规律。【结果】4种植物根、茎的C含量、C和N的含量比(C/N)、C和P的含量比(C/P)、C和K的含量比(C/K)均比在叶片中更高;4种植物叶片的N,P,K的含量及N和P的含量比(N/P)、N和K的含量比(N/K)均比在根、茎中更高。狗牙根和狼杷草在叶片C含量方面明显高于苍耳、苘麻;狗牙根各器官具有略低的N,P,K含量以及较高的C/N,C/P,C/K;狼杷草茎、叶具有较高的N含量和N/P,N/K;苍耳、苘麻叶片具有较高的K含量和K和P的含量比(K/P)。4种植物叶片的C,N,P,K含量随水位的增加均呈现先增加后降低的趋势,而C/N,C/K均呈相反的规律,N/P,N/K,K/P则相对稳定且变异均较小。【结论】4种植物各养分分配策略相似,均优先保障叶片的N,P,K含量以维持自身生长代谢;4种植物间养分含量和计量比特征存在明显差异,形成了各自独特的养分适应机制;水淹胁迫对植物叶片养分含量有明显影响,消落带中部植物养分含量略高于下部和上部,更有利于植物养分积累,下部极端水淹和上部夏季极端干旱可能导致植物养分利用效率提高、生长速率减慢;除C/N以外,消落带草本植物的养分计量比特征对水淹胁迫具有一定的稳定性,表现出较好的内稳性。水淹胁迫能够促使物种养分策略的分化,进而影响消落带生态系统养分的分布格局,同时不同物种形成了对水淹环境独[Purposes]In order to explore the characteristics of nutrient utilization and nutrient distribution of plants in the littoral zone,as well as the adaptive strategies of different plants in the littoral zone,it provides a scientific basis for vegetation restoration and ecological reconstruction in the littoral zone of reservoirs.[Methods]It selected fourrepresentative species of plants that widely distributed in the pengxi river littoral Zone of Three Gorges,including Cynodon dactylon,Bidens tripartita,Abutilon theophrasti,and Xanthium sibiricum.The contents of C,N,P,and K in roots,stems and leaves of plants were determined,and the stoichiometric ratio was calculated.The responses of plant ecological stoichiometric characteristics under different water level gradients were studied by comparing different plant nutrient utilization and distribution strategies.[Findings]The C,C/N,C/P,and C/K of the roots and stems of the four plants were all higher than the leaves.The content of N,P,K and N/P,N/K in leaves were higher than roots and stems.The content of C in leaves of C.dactylon,B.tripartitais significantly higher than that of A.theophrasti and X.sibiricum.Different organs of C.dactylon has slightly lower content of N,P,and K and higher content of C/N,C/P,and C/K.The N content,N/P,N/K in stem and leaf of B.tripartite was higher.The K content and K/P of the leaves of A.theophrasti and X.sibiricum was higher.The contents of C,N,P and K in the leaves of four plants increased first and then decreased with the increase of water level,but C/N and C/K show opposite rules,N/P,N/K,and K/P are relatively stable,and the coefficient of variation is small.[Conclusions]The nutrient allocation strategies of different plants were similar,and the N,P,and K contents of leaves were given priority to maintain their growth and metabolism.There were significant differences in nutrient content and stoichiometric ratio between different plants,which from their own unique nutrient adaptation mechanisms.Water flooding stress has a significant

关 键 词：三峡库区 澎溪河 消落带 植物器官 水位梯度 生态化学计量学 

分 类 号：Q948.118[生物学—植物学]