青藏高原东部4科植物种子大小和比叶面积随海拔和生境的变异

Variation of seed mass and SLA of 63 plant species in different habitats at various altitudes on the eastern Qinghai-Tibet Plateau

种子大小和比叶面积分别是种子植物的繁殖性状和营养性状之一,也是衡量植物功能的2个重要参考。本研究测量4个青藏高原东部常见科(虎耳草科Saxifragaceae;龙胆科Gentianaceae;毛茛科Ranunculaceae;石竹科Caryophyllaceae)的63种植物的种子大小和比叶面积,分析2种性状之间的相关性,并研究海拔和生境因子对其的影响。结果表明,1)种子大小和比叶面积有边际明显的负相关关系(P=0.066);2)无论整体上还是在科内,青藏高原东部植物种子大小与海拔和生境均不相关(P>0.05);3)区域内植物比叶面积随海拔的升高而显著减小;在科内,海拔对毛茛科、龙胆科植物的比叶面积影响显著,而石竹科、虎耳草科植物的比叶面积与海拔不相关;4)草地中植物比叶面积最小,林下最大;在草地中比叶面积随海拔的升高而显著减小,其他生境下海拔对比叶面积没有影响。研究结果反映了青藏高原东部植物对高寒环境不同的响应和适应。

Seed mass and specific leaf area（SLA） are two representative parameters of plant reproductive traits and vegetative traits,both of which are important parts of plant life-histories.We measured the seed mass and SLA of 63 plant species from four families（Saxifragaceae,Gentianaceae,Ranunculaceae and,Caryophyllaceae） on the eastern Qinghai-Tibet Plateau and studied how altitude and habitat influenced them.1） The relationship between seed mass and SLA was marginally significantly negative（P=0.066）.2） Seed mass was not correlated with altitude（P〉0.05） in the four families as a whole and in Ranunculaceae and Gentianaceae,but was significantly negatively correlated with altitude in the other two families.The habitats had no effect on seed mass when considered alone,but had significant effects when combined with altitude.3） SLA significantly decreased with altitude in all four families and in Ranunculaceae and Gentianaceae but not in other two families.4） Moreover,SLA was biggest in the meadow and least in the forest.SLA significantly decreased with altitude in the meadow,but not in other habitats.The variation of the two traits showed an active response or adaptation of the plant to the harsh environment on the eastern Qinghai-Tibet Plateau.