氮和水分添加对黑沙蒿群落优势植物叶片氮磷化学计量特征的影响  

Effects of nitrogen and water addition on leaf nitrogen and phosphorus stoichiometry of the dominant species in an Artemisia ordosica community

作　　者：张文瑾[1] 佘维维[1,2] 秦树高[1,2] 乔艳桂 张宇清[1,2] ZHANG Wen-Jin;SHE Wei-Wei;QIN Shu-Gao;QIAO Yan-Gui;ZHANG Yu-Qing(Yanchi Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of National Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,宁夏盐池毛乌素沙地生态系统国家定位观测研究站,北京100083 [2]北京林业大学水土保持国家林业和草原局重点实验室,北京100083

出　　处：《植物生态学报》2024年第5期590-600,共11页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(U22A20504)。

摘　　要：为了解典型沙生半灌木群落植物在氮(N)沉降和降水增加下的响应机制和适应策略,以毛乌素沙地黑沙蒿(别名油蒿,Artemisia ordosica)群落为对象,研究了N、水分添加及其交互作用下土壤与优势植物黑沙蒿和赖草(Leymus secalinus)叶片N含量、磷(P)含量、N:P及相应的内稳性指数。结果显示:(1)土壤速效N、P养分供应状况和植物养分吸收的内在属性共同影响黑沙蒿和赖草叶片N含量、P含量、N:P对N和水分添加的响应,黑沙蒿和赖草叶片N含量对N和水分添加的响应存在种间差异;(2)黑沙蒿和赖草叶片P内稳性均强于叶片N内稳性,与黑沙蒿和赖草生长均受N限制密切关联;(3)黑沙蒿叶片N、P化学计量内稳性相对较高且养分利用策略较为保守,赖草叶片N、P化学计量内稳性相对较低且养分利用策略较为灵活。结果表明,黑沙蒿在干旱贫瘠的环境中更具竞争力和生长优势。在N沉降和降水持续增加的情景下,黑沙蒿群落物种组成可能因优势植物黑沙蒿和赖草竞争力和养分利用策略的不同而发生变化。Aims Water and nitrogen(N)availability are two of crucial factors affecting the growth of desert plants,and are sensitive to global climate change.With increasing N deposition and precipitation,the understanding of the responses of leaf N and phosphorus(P)stoichiometry of dominant species in sandy semi-shrub community could provide insights into the adaptive strategies of sand-fixing plants in the Mau Us Sandy Land.Methods An experiment of N and water addition was conducted in an Artemisia ordosica community in the southern edge of the Mau Us Sandy Land.Soil available N and P concentrations,soil available N:P,leaf N and P concentrations,leaf N:P,and the corresponding homeostasis index of dominant species A.ordosica and Leymus secalinus were measured.Important findings(1)Soil N and P availability and species identity jointly influenced the response of leaf N concentration,leaf P concentration,and leaf N:P in A.ordosica and L.secalinus to N and water addition,and the leaf N concentration of A.ordosica and L.secalinus showed different responses to treatments.(2)Both A.ordosica and L.secalinus showed higher stoichiometric homoeostasis indices for leaf P than for leaf N,which was closely related to the fact that the growth of A.ordosica and L.secalinus were both N-limited.(3)The stoichiometric homoeostasis indices of leaf N concentration,leaf P concentration,and N:P in A.ordosica were relatively higher than those of L.secalinus,and A.ordosica adopted more conservative nutrient utilization strategies,while L.secalinus adopted more flexible nutrient utilization strategies.Therefore,A.ordosica was more competitive than L.secalinus in growth in arid and infertile environments.Under the scenarios of increasing N deposition and precipitation,the species composition of the A.ordosica community may change due to the contrasting competitiveness and nutrient utilization strategies between A.ordosica and L.secalinus.

关 键 词：毛乌素沙地 氮沉降 降水变化 生态化学计量学 养分限制 内稳性 

分 类 号：Q948[生物学—植物学]