摘要
目前生态系统模型模拟中所用的大多数同化物分配模型是经验性的。同化物分配对植物的生长、竞争及结构的形成有重要的影响,是植物生长的关键,也是植物生长模型中的薄弱环节。总结了影响同化物分配的因素:生理过程和环境因子。指出植物作为一个有机的整体,所有的生理过程都对其有影响,维管束作为各器官间的连接系统,以及同化物的运输管道,其性质对同化物分配有重要的影响。综述了环境因子特别是环境水分条件对同化物分配的影响。总结了以往研究中发现的、主要的同化物分配规律,指出同化物分配的模式极其复杂,分配过程完全是根据环境以及生长阶段变化而变化的、随机应变的过程。对于同化物分配模型按照经验模型,目的性模型,源汇关系模型进行了总结归纳,分析指出:经验性模型应用最多但机理性差;功能平衡模型在模拟营养生长阶段同化物在条与根之间的分配很成功,但应用于其它器官之间很困难;最优化模型适于模拟平衡态下同化物的分配;源汇关系模型机理性最强,可模拟任何器官间的同化物分配,应用范围最广泛。同化物研究取得了很大的进展,但研究中仍存在很多不足:对于各相关过程的研究存在不平衡性;整体水平上同化物分配的机理仍缺乏深入研究;同化物分配对于环境的响应方面的研究相对较弱;缺乏多环境因素的研究;缺乏长期的实验观测研究。作者认为环境与同化物分配相互关系的研究将成为日后研究中的热点问题。
Most ecosystem simulations use empirical models to partition assimilated products based on observations of the allometric relationship among plant organs. Photoassimilates partitioning, with importance influence on plant growth, competition and architecture forming of plant, is an important aspect of ecosystem simulation that deserve more research investiment. The factors influencing partitioning, including environmental factors and physiological processes of plant, were reviewed and analyzed. We pointed out that, as an integrated system, all the processes of plant physiology have influence on partitioning, and as the connective system among apparatuses and conduits of photoassimilate transporting, the properties of vascular bundles have significant impacts on partitioning. The influences of environmental factors, especially water condition, were detailed reviewed. The main rules of photoassimilate allocation founded in various studies were summarized, based on which the complexity of allocation pattern was indicated. The process of allocating is highly dynamic, and depending on environments and phases of plant growth.
Four classes of partition models, empirical models, functional equilibrium models, optimal control models, and source-sink models were reviewed in this paper. The empirical models were widely used with minimal mechanistic assumptions. The function equilibrium models were successful in the simulation of the root/canopy ratio at the periods of the vegetative growth, but were poor to simulate portioning among other organs. The optimal control models were suitable for the modeling under the equilibrium state. The source-sink models were the most powerful and mechanistically based models capable of simulating dynamic photoassimilates partitioning between any organs of the plants.
The research on photoassimilates partitioning showed great progress recently. But there are still questions, especially the questions of plant growth viewed as an integrated system to respond to environmental changes, not fully understood. Long term observations and experiments are still inadequate to allow formulation of a compelling and cohesive carbon partitioning model for ecosystem simulation. This paper also pointed that study of the relationship between the environmental control on photoassimilates partitioning would be hot issues in the future research.
出处
《生态学报》
CAS
CSCD
北大核心
2006年第6期1981-1992,共12页
Acta Ecologica Sinica
基金
国家自然科学基金项目(30590384
90202008
90211002)~~
关键词
同化物分配
植物生长
环境因子
模型
机理
photoassimilates partitioning
plant growth
environmental factors
model
mechanism
