矮嵩草草甸不同功能群主要植物种生长特征与地表温度的相关性分析

基于国际冻原计划(ITEX)模拟增温效应对植物影响的研究方法,设置温度梯度从物种个体水平研究各功能群主要植物种生长特征与地表温度的相关性,以探讨全球变暖背景下,矮嵩草草甸不同功能群植物种生长特征对地表温度升高的响应。结果显示:(1)莎草科功能群黑褐苔草的高度与地表温度呈线性关系(P<0.01),而分蘖数、叶片数与地表温度呈二次函数关系,但不显著;矮嵩草的分蘖数、叶片数及高度与地表温度均呈二次函数形式变化(P<0.05)。(2)多年生禾本科功能群垂穗披碱草和草地早熟禾的分蘖数、叶片数、高度均与地表温度呈线性正相关关系(P<0.01)。(3)杂类草功能群短穗兔耳草的匍匐茎数与地表温度呈不显著的二次函数关系,而叶片数、高度均与地表温度呈线性相关关系(P<0.01);鸟足毛茛的花蕾数、叶片数、高度均与地表温度呈线性相关关系(P<0.01)。研究表明,不同功能群植物种对地表温度升高的响应是不一致的,地表温度持续升高对禾本科功能群植物种的生长有利,而对莎草科、杂类草功能群植物种均不利。

Correlation between Growing Characters of Main Species Belonging to Different Functional Groups and Ground Temperature in Kobresia Meadow

Based on the International Tundra Experiment(ITEX) method,using temperature gradient,the correlation between major plants of functional groups and ground temperature was studied in Kobresia meadow from the individual level.The aim is to discuss the responding for growing characters of major species of different functional groups in Kobresia meadow to temperature increasing in warming background.The results showed that:(1)It was line correlation between the height of Carex alrofusca and ground temperature(P<0.01),but they were quadratic correlation not significant between the number of tillers,leaves and ground temperature;(2)They were quadratic correlation between the number of tillers,leaves and the height of Kobresia humilis and ground temperature(P<0.05).They were line correlation between the number of tillers,leaves and the height of Elymus nutans,Poa pratensis ground temperature(P<0.01).(3)It was quadratic correlation not significant between the number of stolons of Lagotis brachystachya(Forbs functional group) and ground temperature,but they were line correlation between the number of leaves,the height of L.brachystachya and ground temperature;They were line correlation between the number of leaves,buds and the height of Ranunculus brotherusii and ground temperature(P<0.01).It was declared that it was not accordance that species of different functional groups in response to ground temperature was difference.If ground temperature will continue increase in future,it will benefit to species of Gramineae functional group,but it will disadvantage for species of Cyperaceae functional group and Forbs functional group.