卧龙自然保护区油竹子(Fargesia angustissima)生理生态特征的海拔变化

Responses of Physiological and Ecological Traits of Fargesia angustissima to the Altitudinal Changes in Wolong Nature Reserve,Southwestern China

全球气候变化(如温度升高)迅速而强劲地影响着高海拔地区的生态环境,致使植物生长发生变化,因此高山地区成为研究植物环境适应性及其对全球气候变化响应的理想区域。为了认清气候变化如何影响竹子的生长和生理生态特性,本文系统调查研究了卧龙自然保护区内大熊猫典型主食竹种油竹子(Fargesia angustissima(Mitford)T.P.Yi),从其天然分布下限至上限,在卧龙自然保护区沿海拔梯度研究了分株的比叶面积(SpecificLeaf Area,SLA)、基于单位叶面积和单位叶质量的叶氮含量(Narea,Nmass),以及组织非结构性碳水化合物(NSC)含量及其组分。研究结果表明,各调查因子对海拔的响应均是非线性的,表现为随着海拔升高,各调查值先降后升,高峰值出现在分布上限区域(1 810 m),而最低值出现在中海拔区域(1 620 m),反映了环境因子随海拔的非线性变化。分析认为,油竹子的生长受不同海拔环境影响较大。

The strong altitudinal gradients leading to dramatic variations in environmental conditions in mountain regions provide unique and sometimes the best opportunities to study plant responses and adaptation to global climate change.Investigations were made on tissue non-structural carbohydrates content（NSC）,specific leaf area（SLA）,mass-based（Nmass） and area-based（Narea） leaf nitrogen of dwarf bamboos,Fargesia angustissima Yi,growing along elevational gradients in Wolong Nature Reserve.Parameters in tissues changed non-linearly with the increasing elevation.This result may imply that the local-environmental conditions do not change linearly with the altitude.The altitudinal responses of the parameters studied are species-specific.These results may imply that the local-environmental conditions do not change linearly with the altitude.The growth of F.angustissima,as a low-altitude species,may be impacted by precipitation rather than by temperature.Hence,this dwarf bamboo species may be more sensitive to change in the amount and pattern of precipitation caused by the rapid global climate change.