Mycorrhizal functions in the forest floor

森林地面的菌根功能

• 批准号: 502049029
• 负责人: Professorin Dr. Ina Christin Meier
• 金额: --
• 依托单位: Royal Botanic Gardens, Kew
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/502049029?language=en
• 关键词: Mycorrhizal; functions; forest; floor

The mycorrhizal symbiosis is a central component of plant-soil feedbacks and carbon cycles of forest ecosystems. Yet even though it is known that the two major mycorrhizal association types influence litter decomposition and soil organic matter formation differently, it remains unresolved whether this also influences their preference for the forest floor (FF) as a habitat. We hypothesize that mycorrhizal fungi are more dependent on FF carbon (C) in cold or warm nutrient-poor forest stands, since less photosynthates are produced and invested into the fungal symbiont. As a result, the diversity of the mycorrhizal fungal community in the FF increases. At intermediate temperature, when mycorrhizal fungi are stronger limited by nutrient availability than by host C supply, the response of the two major mycorrhizal association type leads to diverging superiority: Arbuscular mycorrhizal fungi are superior in P-poor FFs and ectomycorrhizal fungi in P-rich FFs. We aim to test these predictions in a transect study with mature European beech (Fagus sylvatica L., ECM host) forests admixed with sycamore maple (Acer pseudoplatanus L., AM host) by analyzing the response of the mycorrhizal community composition and activity to rising temperature and inorganic P limitation. To achieve the objectives of our project, we will combine functional trait analyses, isotopic fractionation analysis, a 13C- and 15N-labeling experiment, and extracellular enzyme analyses with next generation sequencing of the mycorrhizal fungal community in the FF and mineral soil. This project will refine our understanding and prediction of the ecology of mycorrhizal fungi in the FF of mixed beech forests, which are increasingly exposed to rising temperature and P limitation.

菌根共生是植物-土壤反馈和森林生态系统碳循环的核心组成部分。然而，即使它是已知的，这两个主要的菌根协会类型的影响凋落物分解和土壤有机质的形成不同，它仍然没有得到解决，这是否也影响他们的偏好森林地面（FF）作为栖息地。我们假设，菌根真菌更依赖于FF碳（C）在寒冷或温暖的营养贫乏的森林看台，因为较少的光合产物产生和投入到真菌共生体。因此，在FF菌根真菌群落的多样性增加。在中温条件下，当菌根真菌受养分有效性的限制比受宿主C供应的限制更强时，两种主要的菌根组合类型的反应导致了分化优势：丛枝菌根真菌在贫磷的FF中占上级优势，外生菌根真菌在富磷的FF中占优势。我们的目标是测试这些预测在横断面研究与成熟的欧洲山毛榉（山毛榉L.，ECM宿主）森林与西卡莫尔枫树（Acer pseudoplatanus L.，分析了温度升高和无机磷限制对菌根菌群落组成和活性的影响。为了实现我们的项目的目标，我们将结合联合收割机功能性状分析，同位素分馏分析，13 C-和15 N-标记实验，胞外酶分析与下一代测序的菌根真菌群落在FF和矿质土壤。这个项目将完善我们的理解和预测的菌根真菌的生态学在FF的混合山毛榉林，这是越来越多地暴露于不断上升的温度和磷限制。