高寒草甸不同演替阶段植物叶片功能性状研究

以甘南高寒草甸演替过程中5个阶段的典型群落为研究对象,对围封样地内不同演替阶段群落叶片功能性状进行比较,分析了围封地内各演替阶段群落水平上主要物种叶性状与环境因子的关系。结果显示:(1)此围封地形成了一个从草本到灌木的演替过程。随着演替的进行,Margalef指数显著增加,Shannon-Wiener指数呈先增加后降低的趋势。(2)从演替前期到演替后期,土壤有机碳(SOC)、土壤全氮(STN)、土壤含水量(SWC)逐渐升高,光照度(LI)、土壤温度(ST)逐渐降低,土壤全磷(STP)呈先降低后增加趋势;叶片有机碳(LCC)、全氮(LNC)、含水量(LWC)逐渐升高;比叶面积(SLA)、磷利用效率(PUPE)、稳定碳同位素(δ13C)逐渐下降,叶片全磷(LPC)先降低后升高,而氮利用效率(PUNE)先升高后降低。(3)RDA冗余分析表明,在此围封样地内,演替前期植物群落叶性状主要受到LI和ST的限制作用。而在演替的中后期SWCWTBZ]是主要影响因子。此研究有助于我们认识高寒草甸生态系统的退化过程所导致的生态环境问题,进而寻求更好的草地恢复和重建方法。

Functional Traits of Plant Leaves at Different Succession Stages in Alpine Meadow

We studied the typical communities in five stages of alpine meadow succession in Gannan. The leaf functionaltraits of different succession stages in enclosed plots were compared, and the relationship between leaf characteristics of main species and environmental factors at community level in each succession stage were analyzed. The results showed that:(1)The enclosure formed a succession process from herbs to shrubs. As the succession progresses, Margalef index increased significantly and Shannon-Wiener index increased first and then decreased. (2)With the succession, soil organic carbon(SOC), soil total nitrogen(STN), soil water content(SWC) gradually increased, light intensity(LI), soil temperature(ST) gradually decreased, soil total phosphorus(STP) decreased first and then increased; leaf organic carbon(LCC), leaf total nitrogen(LNC), water content(LWC) gradually increased; specific leaf area(SLA), phosphorus utilization efficiency(PUPE) and stable carbon isotope(δ¹³C) decreased gradually, leaf total phosphorus(LPC) decreased first and then increased, while nitrogen use efficiency(PUNE) first increased and then decreased. (3)By RDA analysis, in the enclosed plot, leaf traits of plants communities in the early stage of succession were mainly restricted by LI and ST, and leaf traits of plants communities in the middle and late stages of succession were mainly restricted by SWC. The study of community succession and functional changes of plant leaves in enclosed areas will help us to understand the degradation of alpine meadow ecosystem and the decline of biodiversity, and to seek better methods of grassland restoration and reconstruction.