Stoichiometric constraints on resource use, competitive interactions, and elemental cycling in microbial decomposers
Stoichiometric constraints on resource use, competitive interactions, and elemental cycling in microbial decomposers
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DOI：
10.1086/516844
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发表时间：
2007-06-01
影响因子：
2.9
通讯作者：
Loreau, Michel
中科院分区：
文献类型：
--
作者：
Cherif, Mehdi;Loreau, Michel
异养微生物分解者，如细菌和真菌，根据其元素组成和其有机资源的组成，使无机元素矿化或矿化。这一事实对他们与其他无机元素消费者的相互作用有重大影响。我们结合联合收割机的化学计量和资源比的方法在一个模型中描述使用分解的有机和无机资源含有相同的基本元素，研究其后果分解相互作用和元素循环中的作用。我们的模型考虑了有机物的元素组成及其动态平衡的原则。新的预测出现，特别是，（1）化学计量限制产生了两种资源的分解者之间的R* 值的折衷，（2）它们为不同资源和不同元素需求限制的分解者的共存创造了有利条件;（3）结合物种特异性平衡限制条件，在进化的时间尺度上，它们通过有机和无机资源吸引分解者进行共融。此外，我们推导出分解者从消耗无机资源转向排泄无机资源的条件。我们希望我们的预测是有用的，在解释社会结构的分解者和他们的相互作用与其他消费者的无机资源，特别是初级生产者。
Heterotrophic microbial decomposers, such as bacteria and fungi, immobilize or mineralize inorganic elements, depending on their elemental composition and that of their organic resource. This fact has major implications for their interactions with other consumers of inorganic elements. We combine the stoichiometric and resource-ratio approaches in a model describing the use by decomposers of an organic and an inorganic resource containing the same essential element, to study its consequences on decomposer interactions and their role in elemental cycling. Our model considers the elemental composition of organic matter and the principle of its homeostasis explicitly. New predictions emerge, in particular, ( 1) stoichiometric constraints generate a trade-off between the R* values of decomposers for the two resources; ( 2) they create favorable conditions for the coexistence of decomposers limited by different resources and with different elemental demands; ( 3) however, combined with conditions on species-specific equilibrium limitation, they draw decomposers toward colimitation by the organic and inorganic resources on an evolutionary time scale. Moreover, we derive the conditions under which decomposers switch from consumption to excretion of the inorganic resource. We expect our predictions to be useful in explaining the community structure of decomposers and their interactions with other consumers of inorganic resources, particularly primary producers.