摘要
高寒沼泽化草甸作为湿地与草甸之间的过渡类型,其群落物种组成对土壤水分极为敏感。为探讨土壤水分状况对高寒沼泽化草甸植物群落组成物种的影响,移栽玛曲高寒沼泽化草甸群落17个组分物种,在完全避免自然降雨影响的条件下进行3种不同的水分处理(充分浇水、对照和轻度干旱)并分别测量了叶片的净光合速率(A),气孔导度(g)和叶片单位面积干物质含量(LMA)。用充分浇水(FD)和轻度干旱(SD)处理下性状值减去对照(CK)处理下的值,得到各功能性状的差值,以比较不同物种对充分浇水和轻度干旱的响应;同时对光合差值和叶片叶片单位面积干物质含量及气孔导度的差值进行线性回归分析,以探讨叶片表型特性对对光合能力的影响。结果表明:(1)水分对叶片的LMA指标的影响存在显著的物种间差异。(2) A和g对充分浇水和干旱的响应存在显著的物种间的差异,并且受到其原始分布生境的影响。(3)高寒沼泽化草甸植物在不同水分条件下的光合能力主要由气孔调节,而与叶片表型特征没有显著的相关关系。说明高寒沼泽化草甸植物对土壤水分条件极度敏感,在全球变化影响高寒地区的降水格局的背景下,开展高寒草地进行保护和恢复工作应该考虑未来降水变化的影响。
Plant species in alpine swamp meadow which is a successional stage of dried alpine wetland,is sensitive to changes in soil water content,and thus it is important to understand the responses of common species of alpine swamp meadow to changed soil water condition.In order to determine the effects of different soil water content on plants of alpine swamp meadow,we transplanted 17 common species from an alpine swamp meadow to a manipulated environment located in Maqu county of Gansu Province,eastern Qinghai-Tibetan Plateau.These plants were then subjected to three soil moisture regimes:flooding(FD),control treatment(CK),and slightly drought(SD).The net photosynthesis(A),stomatal conductance(g)and leaf dry mass per unit area(LMA)were measured for leaves from 6 plants each species per treatment.We calculated the difference of A,g and LMA between FD or SD and CK for each species,and the relationships between A and g or LMA was analyzed.Results are as follows.(1)The LMA of alpine swamp meadow common species was significant affected by soil water condition,and there were different responses among different species.(2)Significant habitat-specific responses of gas exchange to water condition were found among the species.(3)There were significant correlations between A and g under both treatments,but it was not for A and LMA.As a conclusion,the common species of alpine swamp meadow was strongly influenced by soil water content,in additional;there was significant habitat-specific responses of the morphological traits or physiological taints to different soil water condition.Our findings suggested that the species composition of alpine swamp meadow was very sensitive to change in soil water condition.In the context of global climate change,which is predicted to alter the precipitation regime of alpine area,will be significantly influence the composition and structure of alpine swamp meadow community in the future.This should be considered carefully for protection and restoration of alpine grassland.
作者
李宏林
周浪敏
薛静
孙冉
LI Honglin;ZHOU Langming;XUE Jing;SUN Ran(State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China;Key Laboratory of Restoration Ecology of Cold Area in Qinghai Province,Xining 810010,China)
出处
《生态科学》
CSCD
2023年第4期1-8,共8页
Ecological Science
基金
青海省科技厅自然科学基金(2018-ZJ-929Q)
青海省寒区恢复生态学重点实验室开放课题(2020-KF-10)
国家自然科学基金(32060252)。