毛乌素沙地优势克隆半灌木生物量配置对小尺度植被盖度变异的响应  

Response of biomass allocation to small-scale variation of vegetation coverage in dominant clonal semi-shrubs in the Mu Us Sandland

作　　者：刘凤红[1] 刘建[2] 董鸣[1] 

机构地区：[1]中国科学院植物研究所植被数量生态学重点实验室 [2]山东大学生命科学学院,济南250100

出　　处：《生态学报》2005年第12期3415-3419,共5页Acta Ecologica Sinica

基　　金：国家重点基础发展规划资助项目(2000018607);国家杰出青年科学基金资助项目(39825106)~~

摘　　要：克隆植物根据其构型可以分为游击型和密集型。游击型克隆植物的间隔子长,分株在水平空间的扩展范围大,可以利用更大空间范围内的资源,其通过克隆生理整合作用发生的非局部反应的能力强。由此可以得出的推论之一是,小生境斑块的环境发生变化,生长于其中的密集型克隆植物的反应可能会更灵敏。这种反应可能会体现在生物量以及配置格局的变化上。以毛乌素地区沙生半灌木群落中两种优势克隆植物羊柴(H edy sarum laeve)和油蒿(A rtem isia ord osica)为研究对象,前者是典型的游击型克隆植物,后者是密集型克隆植物。采取野外调查的方式,观测在不同植被盖度的小生境斑块内二者地上生物量分配格局的变化情况,并结合二者的克隆构型和生活史特征试图探讨产生这种格局的原因。结果表明:羊柴的地上各部分生物量对植被盖度变化的响应不如油蒿敏感。这或者是因为羊柴的游击型克隆构型决定其可以跨越小尺度斑块实现克隆生理整合,可以利用不同小生境斑块的资源导致的。油蒿只能利用小生境斑块内的资源,当小生境斑块的条件改变,其生物量以及配置方式也随之发生相应的变化。在繁殖方式上,羊柴的有性繁殖结构以及有性繁殖投资显著小于油蒿。在资源有限的条件下,对一种繁殖方式的投资常常会削弱另一种繁殖方式。羊柴主要依靠克隆繁殖,这或者符合并支持配置理论的观点。Guerrilla and phalanx are the two extreme types of clonal architectures in clonal plants. In general, compared with the clonal plant with phalanx growth form, the guerrilla one has longer spacers. Thus, its ramets may be located in contrasting micro-sites and physiological integration may works amongst ramets. Hence, biomass and biomass allocation can reveal that the remote conditions would have more effects on the ramets of guerrilla clonal plant than those of phalanx one. Hedysarum laeve is a typical clonal plant with guerrilla clonal architecture while Artemisia ordosica with phalanx one. We carried out a field investigation on both dominant clonal half-shrub species in the Mu Us Sandland where vegetation coverage can be indicative of available resource conditions. We selected two mobile, two semi-fixed and two fixed sand dunes, respectively, and set up a 2m×100m transect along each dune slope. In each transect, we measured vegetation coverage in the 2m× 2m quadrates every 20m. We harvested and measured whole aboveground biomass, reproductive biomass, stem biomass and leaf biomass of both species in the quadrates. According to their vegetation coverage, the quadrates were categorized into mobile, semi-fixed and fixed patches. Hedysarurn laeve was less sensitive to the variation of vegetation coverage than Artemisia ordosica. Whole aboveground biomass, reproductive biomass, stem biomass and leaf biomass of H. laeve did not vary with vegetation coverage while A. ordosica did. In addition, reproductive biomass and allocation in H. laeve were lower than in A. ordosica. These results implicated that the guerrilla H. laeve could utilize resources in different microhabitats using clonal physiological integration. Compared to H. laeve, A. ordosica relied more on sexual reproduction to produce offspring.

关 键 词：油蒿 生物量分配 羊柴 毛乌素沙地 生理整合 

分 类 号：Q948[生物学—植物学]