资源异质性环境中的植物克隆生长 :觅食行为

CLONAL GROWTH IN PLANTS IN RELATION TO RESOURCE HETEROGENEITY:FORAGING BEHAVIOR

In nature, essential resources for organisms, such as food for animals and light, water and nutrients for plants, are usually heterogeneously distributed, even at very small scale. As a result, all organisms, particularly plants mostly sessile, have a difficulty in acquiring essential resources from their environments. Animals express various types of foraging behavior to capture heterogeneously distributed essential foods. Clonal growth ( a vegetative reproductive process where by more than one individual of identical genetic composition is formed ) provides clonal plant not only with many “mouths” at different spatial positions, but also with a large spacial movability. As a clonal plant grows in environments characterized by a small scale resource heterogeneity, its inter ramet connection permits a resource sharing among the connected ramets. In addition, it may also allow certain ramets to respond locally and non locally to resousce heterogeneity. This may lead to a division of labor among the connected ramets and a selective placement of ramets in favorable micro habitats. Together these may enhance exploitation of resource heterogeneity by clonal plants, and in turn greatly contribute to maintenance or improvement of fitness. Such a behavior of clonal plants, expressed in heterogeneous environments, is to a large extent comparable to that of animals. Therefore, it has been considered as foraging behavior in clonal plants. More recently, it has been observed that phenotypic plasticity of clonal plants, which is relevant to foraging behavior, varies among species, types of genet architecture as well as among types of plants’ habitats. Foraging in clonal plants and its diversity have been receiving increasingly intensive investigations.