短穗兔耳草克隆生长对高寒草甸土壤营养库衰退的响应  

Response of Clonal Growth of Lagotis brachystachya to Degradation of Soil Nutrition Bank in High-cold Meadow

作　　者：孙涛[1] 王彦龙[2] 施建军[2] 赵景学[3,4] 尚占环[3,4] 

机构地区：[1]中国科学院西北高原生物研究所,青海西宁810008 [2]青海省畜牧兽医科学院草原研究所,青海西宁810016 [3]兰州大学青藏高原生态系统管理国际中心 [4]兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《中国草地学报》2010年第2期47-53,共7页Chinese Journal of Grassland

基　　金：国家自然基金重点项目(30730069);国家自然基金青年项目(30600426)

摘　　要：在退化高寒草甸土壤营养库变化背景下,对短穗兔耳草无性生长特性(基株和分株高度、根长和叶片数目,基株匍匐茎长度、粗度和茎生叶数目等)进行调查分析,结果表明:短穗兔耳草克隆生长特性随草地土壤养分资源丰富程度而变化,其觅食行为受环境异质性资源量影响明显。在不同土壤养分库含量样地,短穗兔耳草匍匐茎出现概率和匍匐茎粗度,以及基株匍匐茎上分株的高度、根长和叶片数依其基株匍匐茎数均不同;具不同匍匐茎数短穗兔耳草的基株高度、根长和叶片数变化亦不同。具2条或不具有匍匐茎的短穗兔耳草基株的高度,在土壤养分资源较为丰富的样地要明显小于养分比较缺乏的样地,土壤速效钾和速效氮与基株高度之间有一定的线性相关性。没有匍匐茎基株和分株根的根长度在土壤养分丰富的样地显著小于养分少的样地,而基株和分株叶片数在不同样地的变化无规律。两条中第一条和具一条匍匐茎上茎生叶片数在土壤丰富的样地大于土壤养分少的样地,但样地间匍匐茎粗度没有差异。相同土壤养分条件下,短穗兔耳草基株、分株以及匍匐茎等无性系生长特性无明显差异。短穗兔耳草克隆生长特征严格按其生境养分资源变化而变化,是一种环境异质性变化的适应性植物。The clonal properties（the height,root length,leaf numbers of genet and ramet as well as the length,thickness and leaf numbers on stem） of L.brachystachya were investigated under the background of change of soil nutrition bank in degraded high-cold meadow,the results indicated that the clonal properties of L.brachystachya varied with the richness of nutritional resource in soil and its foraging behavior was affected obviously by environment heterogeneity.In different soil nutrition plots,the arisen probability of L.brachystachy,thickness of stolon,as well as the height,root length and leaf numbers of ramet in stolons were different,the same varying trend also occurred in the height,root length and leaf numbers of genet.The height of genets having no stolon or possessing two stolons were obviously higher in plots where nutritional resource was rich,and there was linear relationship to some degree between available K,N and the height of genet.The roots of ramet and genet without stolon in plots that were rich in soil nutrition were significantly less than these in plots that were poor in soil nutrition,while their leaf numbers did not show the same varying trend.The leaf numbers in stem of the first one of the two stolons and the only one were the most in plots possessing abundant soil nutrition,and the thickness of stolons did not show any difference.There was no significant difference among genets and stolon of L.brachystachy and ramet of stolon in same soil nutrition.Therefore,the clonal growing characteristics of L.brachystachy was closely correlated to the nutritional resource of environment,which was a kind of plant of adapting the change of environment heterogeneity.

关 键 词：高寒草甸 养分资源 短穗兔耳草 形态可塑性 环境异质性 

分 类 号：S812.2[农业科学—草业科学]