降水变化和叶龄对油蒿群落植物-土壤化学计量特征与生产力的调控  

Regulation of plant⁃soil stoichiometric characteristics and productivity of Artemisia oleifera communities by precipitation variability and leaf age

作　　者：赖宝朴 于明含[1,2] 王春媛 张富崇 张建玲 LAI Baopu;YU Minghan;WANG Chunyuan;ZHANG Fuchong;ZHANG Jianling(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Yanchi Ecology Research Station of Mu Us Desert,Yanchi 751500,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]宁夏盐池毛乌素沙地生态系统国家定位观测研究站,盐池751500

出　　处：《生态学报》2024年第7期2898-2906,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(31700639);国家重点研发计划(2019YFC0507601)。

摘　　要：在掌握典型荒漠植物油蒿化学计量学特征沿随降水量变化的响应特征,并从叶片间的养分协调分配的角度阐明油蒿维持生产力的生物学机制,为气候变化背景下荒漠植被的演变预测提供依据。通过野外降水控制实验的方法,设置6个降水量梯度(减雨70%、减雨50%、减雨30%、自然降水、增雨30%和增雨50%),分别测定不同降水量下油蒿群落生产力及叶片、土壤的化学计量参数。结果表明:1)降水量增加的情况下,油蒿群落土壤TP含量由于淋溶作用而显著降低;降水量减少情况下,油蒿林地土壤SOC、TN、TP含量并未改变。油蒿叶片的SOC、TN含量在降水增加时无显著变化、降水减少时含量增加,降水过多或过少都会降低叶片TP含量。2)不同成熟度的叶片养分元素含量对降水变化具有差异响应。成熟叶片养分含量容易受到环境的影响,幼叶养分元素含量较为稳定,在降水减少的情况下,油蒿优先将C、P分配给了幼叶,选择牺牲成熟叶以维持幼叶的生长。3)油蒿的生产力随降水量的增加而升高,油蒿ANPP在增雨30%处理组达到最大值,但在增雨50%时ANPP降低,这与过量的降水引发土壤养分流失有关。ANPP与幼叶TP含量相关性极显著,与成熟叶各元素含量相关性均不显著,由此可以推测,在降水变化的情境下,油蒿存在养分内在生物学调节机制以实现植株最优生产效率。This study aims to understand the response of the chemometric characteristics of Artemisia ordosica along with precipitation changes and to elucidate the biological mechanism of productivity maintenance of A.ordosica from the perspective of coordinated nutrient distribution among leaves,so as to provide a basis for predicting the evolution of desert vegetation under the background of climate change.By means of field precipitation control experiments,six precipitation gradients were set,and the productivity of A.ordosica populations and the chemometric parameters of leaves and soils were measured under different precipitation levels.The results showed that:1)Total Phosphorus content of soil in Artemisia oleifera communities decreased significantly due to leaching when precipitation increased,while soil organic carbon,total nitrogen and total phosphorus contents of soil in Artemisia oleifera woodland did not change when precipitation decreased.The SOC and TN contents of leaves of Artemisia oleifera did not change significantly when precipitation increased,but increased when precipitation decreased,and too much or too little precipitation would reduce the TP contents of leaves.2)Nutrient content of leaves at different maturity levels responded differently to changes in precipitation.The correlation between mature leaves of Artemisia oleifera and soil stoichiometry was significant,while the correlation between young leaves and soil stoichiometry was not significant.The nutrient content of mature leaves was easily affected by the environment,while the nutrient content of young leaves was more stable.Artemisia oleifera preferentially allocated C and P to the young leaves under the condition of reduced precipitation,choosing to sacrifice mature leaves to maintain the growth of young leaves.3)The productivity of Artemisia oleifera increased with the increase of precipitation,and the aboveground net primary production of Artemisia oleifera reached the maximum value in the 30% rainfall increment treatment group,but the ANP

关 键 词：化学计量特征 降水量 土壤养分 叶片成熟度 地上净初级生产力 

分 类 号：Q948.113[生物学—植物学]