摘要
[目的]水分是限制干旱区植物生长与生存的重要因素,为探明降水变化对荒漠植物化学计量特征的影响,以及C、N、P和K元素在植物各器官中的分配规律。[方法]以国家二级重点保护的珍稀濒危植物且是荒漠区唯一常绿阔叶灌木沙冬青为研究对象,分析沿自然降雨梯度下,沙冬青根-茎-叶的元素含量及其化学计量比的变化特征,了解其生长的适应机制和生存策略。[结果]沙冬青各器官C含量表现为叶>茎>根,而N、P、K营养元素含量均表现为叶>根>茎,N、P、K三大营养元素在叶片中的富集,可以提高沙冬青光合速率,为植物的生长与繁殖提供充分的物质保障,反映了资源分配模式和植物生长策略。沿自然降雨梯度,沙冬青的根、茎、叶之间主要表现为协同关系且存在着同时投资的生态策略,N和P含量在各器官中均随着降雨量的增加呈上升趋势,而K均呈下降趋势,沙冬青通过提高各器官K含量和降低N、P含量来应对干旱胁迫的环境。器官间的养分协同性远高于器官内部,各器官中的N:P在不同降雨梯度间相对比较稳定,说明沙冬青以保守的养分利用方式抵消元素含量随环境的变化,且N:P比值均大于16则生长主要受P限制。[结论]各器官N、P、K化学计量特征沿降雨梯度具有相同趋势,但在不同器官间呈现显著差异,而化学计量的灵活性是实现植物自我调节的重要方式,有助于植物在不同环境条件影响下维持自身正常的生命活动。
[Objective]Water is an important factor limiting the growth and survival of plants in arid areas.The effects of precipitation changes on the desert Phytochemistry metrological characteristics,and the distribution of C,N,P and K elements in various plant organs are explored.[Method]Based on the secondclass of rare-endangered plants in China,Ammopiptanthus mongolicus,the only evergreen broad-leaved shrub in desert area,this paper analyzed the ecological stoichiometric characteristics of roots,stems and leaves of A.mongolicus under different precipitation gradients.[Results]The results showed that the C content in the leaves was the most,followed by stems and roots,the nutrient contents of N、P and K in the leaves were also the most,followed by the roots and stems.The enrichment of the three nutrient elements N,P and K in the leaves could improve the photosynthetic rate of A.mongolicus and provide enough material support for plant growth and reproduction,reflecting the resource allocation pattern and plant growth strategy.Along the natural precipitation gradient,the roots,stems and leaves of A.mongolicus mainly showed a synergetic relationship.The content of N and P in each organ showed an upward trend with the increase of precipitation,while K showed a downward trend.A.mongolicus responded to the drought stress environment by increasing the content of K in each organ and reducing the content of N and P,indicating that there is an ecological strategy of simultaneous investment between the roots,stems and leaves of A.mongolicus.The ratio of N:P in each organ was relatively stable among different precipitation gradients.A.mongolicus counteracts the changes of element content with the environment by coordinating nutrient conservation strategies in a conservative way.The nutrient synergy between organs was much higher than that within organs.The N:P ratios of organs were all greater than 16,indicating that the growth of A.mongolicus was mainly limited by P.[Conclusion]The stoichiometric characteristics of N,P,K in each
作者
董雪
海鹭
韩春霞
庞嘉诚
李帅
王丹阳
黄雅茹
卢琦
DONG Xue;HAI Lu;HAN Chun-xia;Pang Jia-cheng;LI Shuai;Wang Dan-yang;HUANG Ya-ru;LU Qi(Institute of Ecological Conservation and Restoration,CAF,Beijing 100091;Experimental Center of Desert Forestry,CAF,National Long-Term Scientific Research Base of Comprehensive Control in Ulan Buh Desert,Inner Mongolia Dengkou Desert Ecosystem National Observation Research Station,Inner Mongolia Dengkou 015200)
出处
《林业科学研究》
CSCD
北大核心
2023年第5期60-71,共12页
Forest Research
基金
国家自然科学基金项目(32101595)
中央级公益性科研院所基本科研业务费专项资金(CAFYBB2021MA006,CAFYBB2021MC002-02)。
关键词
沙冬青
生态化学计量学
根-茎-叶
自然降雨梯度
权衡策略
Ammopiptanthus mongolicus
ecological stoichiometry
root-stem-leaf
natural precipitation gradient
trade-off strategies
