阿拉善高原荒漠植被组成分布特征及其环境解释 Ⅲ.植物功能群多样性对环境因素的响应  

Environmental Effects on Distribution and Composition of Desert Vegetations in Alxa Plateau:Ⅲ. Correlation between plant functional type's diversity and environmental factors

作　　者：何明珠[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所沙坡头沙漠试验研究国家站,甘肃兰州730000

出　　处：《中国沙漠》2010年第2期278-286,共9页Journal of Desert Research

基　　金：中国科学院"西部之光"项目;国家杰出青年基金项目(40825001);国家科技支撑计划项目(2007BAD46B03)共同资助

摘　　要：采用水分生态型(包括旱生植物、旱中生植物、中生植物和湿生植物)、生活型(灌木、半灌木、多年生草本和一二年生草本)和植物主要光合途径(C3和C4)等方法将研究区的植物种类进行了功能群(functional groups/types)划分,为进一步认知荒漠生态系统的结构、功能和过程提供了分析基础。植物功能类群相对集中是阿拉善荒漠植被组成的一个重要特点,这主要和植物趋于旱化、生态型相对简单密切相关。按优势功能群依次为:PFTs1(旱生C3一二年生草本)、PFTs2(旱生C3多年生草本)、PFTs3(旱生C3灌木)、PFTs4(旱生C3半灌木)、PFTs5(旱生C4一二年生草本)、PFTs7(旱生C4灌木)和PFTs8(旱生C4半灌木)。气候、土壤理化指标决定着植物功能类群的分布。其中年均降水量、湿润系数决定着植物的生态型、生活型在水平地带上的分布特征,同时,也影响C3和C4植物(海拔梯度上)的分布。土壤容重、砂粒、粉粒含量决定着植物生活型特征,而土壤pH值、Cl-、SO42-和Ca2+决定着植物水分生态类型的空间分布。这些结果揭示了极端干旱区植物对胁迫环境响应的多样性,是对极端环境条件下如何理解生物多样性维持机制和可持续发展的较好生态学解释。According to ecotypes （including xerophyte,mesophyte and hygrophyte）,life forms （including shrub,subshrub,perennial grass and biennial or annual plants） and photosynthetic pathway （including C3 and C4）,investigated plants are divided into different plant functional types（PFTs）,which provides analytic foundation for understanding the structure,function and process of desert ecosystems.PFTs are relatively simple is an important trait for desert vegetation in Alxa,which is mainly induced by simple ecotypes of xerophyte.The dominant PFTs in Alxa are sorted from high to low as：PFTs1（xerophytic C3 annual and biennial grass）,PFTs2 （xerophytic C3 perenial grass）,PFTs3 （xerophytic C3 shrub）,PFTs4 （xerophytic C3 subshrub）,PFTs5 （xerophytic C4 annual and biennial grass）,PFTs7 （xerophytic C4 shrub） and PFTs8 （xerophytic C4 subshrub）.The distribution of PFTs is controlled by climate and soil physical-chemical indices,among which annual precipitation and moisture coefficient control the distribution of ecotypes and life form along horizontal zonality,also affect the distribution of C3 and C4 along the altitudinal zonality;soil bulk weight and percentage of sand and silt determine the characteristics of plant life forms,and content of pH,Cl^-,SO^2-4 and Ca^2＋ affect the distribution of ecotypes.These results imply the different responding mechanisms of arid plants to stressed environment,which is a scientific and ecological interpretation for understanding mechanisms of maintaining biodiversity and sustainable development under the extreme environmental conditions.

关 键 词：植物功能群(型) 光合作用途径 生活型 生态型 干旱胁迫 

分 类 号：Q948.15[生物学—植物学]