森林生态系统中初级生产者-分解者养分的关系

 森林生态系统中,初级生产者和分解者之间的养分关系,是一种既互利又竞争的复杂关系。通过构建初级生产者-分解者系统的养分流动模型,分析分解者增长受碳限制或受养分限制的判断标准。在假定整个系统封闭的前提下,讨论初级生产者与分解者实现共存并保持长久稳定的条件:一是分解者必须受碳限制,这要求分解者较之初级生产者对养分吸收具有更强的竞争力;二是矿化系数与碎屑化系数之比(a41/a23)要足够大于在初级生产者中的碳/养分与在分解者中的碳/养分之比(α/β)。这表明,从化学计量论的角度来看,生态系统的持续和稳定,对碳/养分之比和植物与微生物的竞争能力方面有严格的要求。

Discussion on the Nutrients Relationship Between the Primary Producers and Decomposers in Forest-ecosystem

The nutrients relationship between the primary producers and decomposers in forest-ecosystem is a mutua-competitive and complex relationship. By constructing a flux model of nutrients for a primary producer-decomposer e-cosystem, a determining standard of decomposers increase confined by carbon or nutrients limitation is analysed. Meanwhile , the conditions under which primary producers and decomposers are able to coexist and hence an ecosystem is able to persist are examed, assuming that the system be closed. They include, first, decomposers must be confined by the carbon, that means decomposers are more competitors than primary producers for nutrient uptake. Second, the ratio of mineralization rate to death and excretion rate (a₄₁/a₂₃) must be larger enough than the ratio of carbon /nutrient in primary producers to that in decomposers (α/β) . All these results showed that strict conditions on the carbon/nutrient ratios and competitive abilities of plants and microorganisms must be required to ensure the persistence of ecosystem when stoichiometry is taken into account in ecological process.