不同坡向高寒退化草地狼毒株高和枝条数的权衡关系 - 植物生态学报.pdfVIP

植物生态学报 2014, 38 (3): 281–288 doi: 10.3724/SP.J.1258.2014.00025 Chinese Journal of Plant Ecology 不同坡向高寒退化草地狼毒株高和枝条数的权衡 关系 * 侯兆疆 赵成章 李 钰 张 茜 马小丽 西北师范大学地理与环境科学学院甘肃省湿地资源保护与产业发展工程研究中心, 兰州 730070 摘 要 权衡关系是生活史对策理论的基础, 株高和枝条数的权衡关系对理解植物在不同生境下的表型可塑性有重要意义。 该研究选择祁连山北坡高寒退化草地, 利用ArcGIS建立研究区域的数字高程模型(DEM), 并提取样地坡向数据, 采用广义相 加模型(GAM)与偏相关分析相结合的方法, 分析了不同坡向影响下狼毒(Stellera chamaejasme)种群株高和枝条数的关系。结 果表明: 随着坡向由北坡转向东坡、南坡、西坡, 草地群落地上生物量和盖度呈“减小—增大—减小” 的变化趋势, 群落高度 则先增大后减小; 坡向是影响狼毒株高和枝条数空间分异的主要地形因子; 随着坡向由北、东转向西、南, 狼毒种群株高呈 下降趋势, 而枝条数呈上升趋势, 二者表现出此消彼长的权衡关系, 狼毒植株比叶面积先增大后减小。不同坡向狼毒株高和 枝条数的权衡关系, 反映了异质生境中资源多重竞争下狼毒生物量分配机制和提高种群适应性的种群更新策略。 关键词 坡向, 枝条数, 祁连山北坡, 株高, 狼毒, 权衡 Trade-off between height and branch numbers in Stellera chamaejasme on slopes of different aspects in a degraded alpine grassland * HOU Zhao-Jiang, ZHAO Cheng-Zhang , LI Yu, ZHANG Qian, and MA Xiao-Li Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province, College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China Abstract Aims Trade-off is the basis of life history strategy theory. Elucidation of the trade-off between plant height and branch numbers is important for understanding the phenotypic plasticity of plants under different habitat condi- tions. Our objective was to examine how Stellara chamaejasme would adapt to changes in slope aspect through trade-off between height and branch numbers. Methods In a degraded alpine grassland on the northern slope of the Qilian Mountains, Gansu Province, China,