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Interactions between root C, microbial activity and turnover, and food web complexity

根 C、微生物活动和周转以及食物网复杂性之间的相互作用

基本信息

批准号：
62031216
负责人：
Professor Dr. Yakov Kuzyakov
金额：
--
依托单位：
Ökopedologie der gemäßigten Zonen
依托单位国家：
德国
项目类别：
Research Units
财政年份：
2008
资助国家：
德国
起止时间：
2007-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/62031216?language=en
关键词：
Interactions between root microbial activity

项目摘要

Microbial activity is the key parameter of turnover of microbial biomass and of soil organic matter (SOM) and it strongly depends on the availability of rhizodeposits and litter as the primary carbon (C) sources. Beside respiration, other microbial activity parameters were never linked with the turnover of microorganisms and of SOM. In this project we challenge to link microbial and SOM turnover estimated by δ13C after C3/C4 vegetation change and by 13C/14C labeling experiments with 20 parameters of microbial activity such as substrate limited and unlimited respiration, maximal and real specific growth rates, substrate affinity and mineralization potential, activities of enzymes. Time and depth gradients will be used in the ongoing and new wheat/maize field experiments for evaluation of root effects on microbial activity parameters and δ13 C based turnover of microbial C and SOM over long periods (months to years). The effects of root-C on short-term turnover and activity parameters will be evaluated comparing rhizosphere and bulk soil in new experiments. In model studies focused on binary links, multitrophic interactions and microbial loop the microbial activity parameters will be linked with complexity and abundance of microbial grazers. These data will be used for modeling of C fluxes within the soil food web and microbial turnover depending on grazing intensity. Finally we will suggest microbial activity proxies adequately reflecting microbial turnover.

微生物活性是微生物生物量和土壤有机质周转的关键参数，它强烈依赖于作为主要碳(C)来源的根际沉积物和凋落物的有效性。除呼吸作用外，其他微生物活性参数从未与微生物周转和土壤有机质周转联系在一起。在这个项目中，我们试图将C3/C4植被变化后由δ13C估计的微生物和土壤有机质周转量联系起来，并通过13C/14C标记实验，使用20个微生物活性参数，如底物限制和无限呼吸、最大和实际比生长速率、底物亲和力和矿化潜力、酶活性。时间和深度梯度将用于正在进行的和新的小麦/玉米田间试验，以评估根系对微生物活动参数和基于δ13C的微生物碳和有机质在长时间(数月至数年)内的周转的影响。在新的实验中，将通过比较根际和非根际土壤来评估根-C对土壤短期周转和活性参数的影响。在侧重于二元链接、多营养相互作用和微生物循环的模型研究中，微生物活性参数将与微生物食草动物的复杂性和丰度联系在一起。这些数据将被用来模拟土壤食物网内的碳通量和微生物周转，这取决于放牧强度。最后，我们将推荐能够充分反映微生物周转情况的微生物活性指标。