排序和广义线性模型与广义可加模型在植物种与环境关系研究中的应用_朱源

排序和广义线性模型与广义可加模型在

植物种与环境关系研究中的应用

3

朱　源　康慕谊

33

(北京师范大学资源学院中国生态资产评估研究中心环境演变与灾害教育部重点实验室,北京100875)

摘　要　排序和广义线性模型(G eneralized Linear Model ,G LM )与广义可加模型(G oneralized Additive

Model ,G AM )是研究植物种与环境间关系的重要方法。基于线性模型的排序方法应限定于环境梯度较短的植被数据,而基于单峰模型的排序方法更适用于梯度较长的情况。PCA 、CA/RA 系列和CCA 系列是常用的排序方法。同时进行环境数据和植被数据分析的CCA 系列,能清楚地得出植物种与环境间的关系。CCA 改进后的DCCA 和PCCA ,是现今较理想的排序方法。G LM 和G AM 实质上是用环境变量的高阶多项式来拟合植物种与环境变量的关系。G LM 和G AM 扩展了植物种与环境变量之间的关系模型,能深入地探讨植物种与环境间的关系。G LM 主要是模型决定的,而G AM 主要取决于原始数据。一般来说,排序能得出研究区域的主要环境梯度,提供了物种聚集和植物群落的概略描述。G LM 与G AM 对于深入研究单个植物种与环境间的关系具有优势。在实际研究中,两种方法结合使用能互补不足。

关键词　植物种2环境模型,排序方法,广义线性模型与广义可加模型,方法比较

中图分类号　Q948 文献标识码　A 文章编号　1000-4890(2005)07-0807-05

Application of ordination and G LM/G AM in the research of the relationship betw een plant species and envi 2ronment.ZHU Yuan ,K AN G Muyi (China Ecological Assessment Research Center ,Key L aboratory of Envi 2ronmental Change and N atural Disaster ,Minisit ry of Education ;College of Resources Science and Technolo 2gy ,Beijing Norm al U niversity ,Beijing 100875,China ).Chinese Journal of Ecology ,2005,24(7):807～811.

Ordination and G LM/G AM are both important methods to explore the relationship between plant species and environment.G enerally ,ordination methods ,based on linear model ,are suitable for dealing with the vegetation within a comparatively short environmental gradient ,while those based on unimodal model are more suitable for tackling with the vegetation distributing along a longer gradient.PCA ,CA/RA series and CCA series are the most commonly used ordination methods.Involving the environmental data in the analysis ,CCA series could demonstrate the relationship between plant species and environment clearly.After modification ,DCCA and PCCA are considered to be ideal ordination methods at present.Essentially ,G eneral Linear Model (G LM )and G eneral Additive Modal (G AM )were using the high power polynomials of environmental variables to fit the response of plant species to environment.S o ,the models for delineating the relationship between species and environment have been enhanced through the introduction of G LM and G AM in recent years.G LM is ba 2sically driven by model ,while G AM is more driven by data.In comparison ,ordination can obtain the main en 2vironmental gradient and provide the general information of species assembling and plant community in the study area.G LM and G AM have advantages in probing deeply into the relationship between plant species and environment.In practice ,the two kinds of methods can yield better results when used in combination.K ey w ords species 2environment model ,ordination ,G LM and G AM ,methods comparison.

3国家自然科学基金资助项目(40271047和40371043)。33通讯作者

收稿日期:2004-09-12 改回日期:2004-11-19

1　引　言

植物种与环境间的关系是植被生态学研究的重

要内容之一[3,15～18]。植物种的空间分布与环境之间存在密切的关系,这是比较公认的一点。但是,环境以何种方式影响植物种,在多大程度上决定植物种的空间分布格局,以及植物种对于环境做出何种反应,这些问题仍然是研究的热点。其中一个重要

的原因就是,自然界植被分布格局的成因相当复杂。排序(ordination )是植被生态学研究的重要手段之一。植物种排序可用于解释植物种的空间分布及其与环境的关系。排序是基于“植被连续体”的假设,即植被的连续变化一般与环境变量的连续变化一

生态学杂志Chinese Journal of Ecology 2005,24(7):807～811