泥炭地储存了全球1/3的土壤碳，其中大量的碳累积与土壤胞外酶的活性及其化学计量特征密切相关。目前，泥炭地土壤胞外酶活性的化学计量特征的研究十分匮乏，有限的研究主要关注环境因子的调控机制，对泥炭地土壤胞外酶活性的化学计量特征的时空分布格局尚缺乏系统研究，尤其是生物因子（主要是植物和微生物）的调控机制方面存在知识空白。本项目拟以长白山区哈泥泥炭地为研究样地，综合野外连续观测、植物功能群剔除和室内控制实验，沿环境梯度研究：1）土壤胞外酶活性的化学计量特征的时空变化；2）细菌和真菌的相对贡献及群落结构改变对酶活性的化学计量特征的调控机制；3）主要植物功能群通过植物–微生物级联系统对酶活性的化学计量特征的影响机制。本项目有望从化学计量学角度揭示植物–微生物级联系统调控泥炭地有机质分解、能量流动及养分循环的酶学机理，为湿地生态系统过程模型的验证与优化提供数据和理论支持，推动泥炭地化学计量学理论的发展。

Peatlands store one third of the global soil carbon, in which the large carbon storage is closely regulated by the activities and stoichiometry of the exoenzymes. There is a dearth of knowledge on the stoichiometry of the exoenzymatic activities in peatlands, though limited endeavor has been dedicated to assess the impact of abiotic controls. Little is known about the spatial and temporal patterns of the stoichiometry of the exoenzymatic activities in peatlands, especially the biotic controls, namely the impacts of plants and microbes. In this study, via field-based observations, vegetation removal manipulations and incubation experiments in Hani Peatland in the Changbai Mountains, we intend to examine (1) the spatial and temporal variation in the stoichiometry of the exoenzymatic activities along a natural environmental gradient; (2) the relative contribution of bacterial and fungal community in regulating the stoichiometry of the exoenzymatic activities; and (3) the underlying mechanism of the controls of the cascade from plants to microbes on the stoichiometry of the exoenzymatic activities. Our results will disclose the mechanism of the exoenzymatic controls of the plant-microbe cascade on organic matter decomposition, energy flow and nutrient biogeochemical cycles in northern peatlands and advance the validation and optimization of process-based models in wetland ecosystem. Eventually, we endeavor to make contribution to advance our current development of the theories of ecological stoichiometry in peatlands.