Microbial interactions and phosphorus mobilization in forest soils - effects of carbon, nitrogen and phosphorus availability

森林土壤中的微生物相互作用和磷动员——碳、氮和磷有效性的影响

• 批准号: 240802859
• 负责人: Professorin Dr. Ellen Kandeler
• 金额: --
• 依托单位: Fachgebiet Bodenbiologie (310b)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/240802859?language=en
• 关键词: Microbial; interactions; phosphorus; mobilization; forest

The newly established N x P application experiment will be used to test whether nutrient addition changes fungal-fungal interactions towards higher dominance of saprotrophic fungi due to the resulting intense mycelial growth at the surface of forest soils. Fungal-fungal interactions in the nutrient addition experiment may change due to an increase in nutrients at either constant or slightly higher carbon availability (due to enhanced plant growth), but girdling decreases the C transfer from trees into the soil environment. Therefore, we will test whether a decrease in the amount of C derived from rhizodeposition reduces the importance of symbiotic P mobilization by ectomycorrhizal fungi (EMF) in soils. Since the ability to cleave high molecular organic carbon compounds is necessary for microorganisms to access N and P containing compounds bound up in complex biotic structures like roots and litter, we want to investigate the relative roles of saprotrophic and EMF during decomposition of organic compounds. The ratio of oxidative to hydrolytic enzyme activities will give us an indication whether the exclusion of EMF will modify the behaviour of the soil microbial community during decomposition of organic matter and consequently during the release of nutrients from organic matter. Metagenomic analyses of the dominant EMF in our soil-in-growth experiment will demonstrate whether EMF have the genetic potential to decompose organic matter. The addition of Mn peroxidase under lab conditions will prove whether oxidative enzymes might liberate otherwise protected organic N and P compounds for subsequent microbial decomposition. We will continue our intense collaborations with other groups within the SPP interested in interactions between plants and soil microorganisms.

新建立的N x P应用实验将被用来测试是否营养添加改变真菌真菌的相互作用对更高的优势腐食真菌，由于在森林土壤表面产生强烈的菌丝生长。真菌-真菌的相互作用在营养添加实验中可能会改变，由于在恒定或略高的碳可用性（由于增强植物生长）的营养增加，但环剥减少了从树木到土壤环境中的C转移。因此，我们将测试是否减少来自根沉积的碳量减少的重要性外生菌根真菌（EMF）在土壤中的共生磷动员。由于裂解高分子有机碳化合物的能力是必要的微生物获得N和P的化合物结合在复杂的生物结构，如根和凋落物，我们要调查腐解和EMF在有机化合物的分解过程中的相对作用。氧化水解酶活性的比率将给我们一个指示是否排除电动势将修改在有机物分解过程中的土壤微生物群落的行为，从而在有机物的养分释放。在我们的土壤生长实验中，对占主导地位的EMF进行宏基因组学分析将证明EMF是否具有分解有机物的遗传潜力。在实验室条件下添加锰过氧化物酶将证明氧化酶是否可以释放出受保护的有机氮和磷化合物，用于随后的微生物分解。我们将继续与SPP内对植物和土壤微生物之间的相互作用感兴趣的其他小组进行密切合作。