植物生活史型的多样性及动态分析

Dynamic Analysis and Diversity of Plant Life Cycle Forms

主要阐述了植物生活史型的基本定义和基本模式。根据植物的生态幅 (Ecologicalamplitude)、适合度 (Fitness)和能量分配格局将植物生活史型划分出 V生活史型、S生活史型和 C生活史型 3个基本类型以及 VS生活史型、SV生活史型、CS生活史型、SC生活史型等 6个具有混合特征的过渡类型。文中分析了权衡 (Trade-off)植物生活史各阶段的能量需求 ,使之合理地进行能量分配 ,进而使植物生活史型获得最佳的繁殖和存活效益以及最大的适合度的重要性 ,指出初生代谢和次生代谢与植物生活史型及其生活史型之间相互转换的密切关系。初生代谢物质主要用于营养生长 ,次生代谢物质主要用于促进繁育和拮抗环境胁迫。植物生活史型在特定时空中依生境的连续变化而发生相互转换 ,呈现出具动态特征的植物生活史型谱。提出了植物生活史型的形成机制 ,即生境中的资源状况和干扰程度构成了环境筛的径度 ,进而形成选择压力 ,以使植物按需分配能量 ,合成初级代谢产物或次级代谢产物来应对选择压力 ,形成自身的生态幅和适应对策 ,最终与生境相互作用过程中表现出的适合度来表征相应的生活史型。还提出了植物生活史型之间相互转化的机制 ,即每一种植物生活史型均有与该生活史型相对应的生境类型、选择压力、代谢物质和生活史对策 ,由?

This paper mainly discussed the basic definition and types of plant life cycle form. According to the plant ecological amplitude, fitness and energy allocation patterns, plant life cycle form could be classified as three basic forms (V form: vegetative growth form; S form: sexual reproduction form and C form: clone reproduction form) and six transitional forms (VS form, SV form, CS form and SC form, VC and CV form) which combine features of three basic forms. By trading off the energy allocation among different plant cycle phases, plants optimize their energy utilization and adopt a specific plant life cycle form with the characteristics of best reproductive and survival benefits as well as maximum fitness to habitats. Moreover, our results indicate that primary metabolism and secondary metabolism might be closely correlated with plant life cycle forms and their transformation between forms. Generally speaking, primary metabolite is mainly used in vegetative growth, but secondary metabolite may be mainly used to promote propagation and over come environmental stress. The plant life cycle form of one specific species could transform from one form to another to adapt to the changing environment. This transformation process is characterized as a dynamic process and form the spectrum of plant life cycle forms of this species. The developing mechanism of plant life cycle form is also discussed in this paper. The size of an environmental sieve (resource status and disturbance degree of habitat) results in the selective pressure. According to the pressure intensity, plants optimize their energy allocation with regard to the need of their different organs by way of producing primary and secondary metabolites, These result in the adaptive strategy and ecological amplitude of one specific species. Finally, fitness manifested by the interaction between the habitat and the adaptive strategy can be characterized as plant life cycle form. Furthermore, this paper also discusses the transformation mechanism between the plant life cycle forms. Because each species has its specific habitat type, selective pressure, metabolite and adaptive strategy, habitat also has a transformational change with the continuous change in spatial and temporal scales. These result in the formation of transformation types of habitat. These kinds of habitat enhances the transformational changes in selective pressure, metabolite and adaptive strategy, which form their transformation types, respectively. As a result, the inter\|transformation processes of plant life cycle forms (so\|called transformation types) were observed. The spectrums of plant life cycle forms of five species including Rhodiola sachalinensis were exemplified to analyze the dynamic features of these spectrums and their possible correlation to the community characteristics. Our results indicated that: First,plants mainly with a V life cycle form generally have a stable population because of their relative big vegetative body, long lifespan and offspring production by normal sexual reproduction. Second, plants with a S life cycle form easily form a eruption population because their diversified genetic message, which is inherited from double genomes of their parent through sexual reproduction, could induce their strong ability to acclimate to the changing environment; Finally, plants with a C life cycle form easily form an endangered population because their gene message is just duplicated from one parent through clone reproduction, which is uniform and have a relative weak ability to acclimate to the changing environment.