Linking microclimate, deadwood microbial diversity, adaptation mechanisms and ecosystem processes

依赖枯木的真菌和细菌是森林中物种最丰富的群体之一，由于它们参与了有机物质的周转，因此对生态系统的功能做出了重大贡献。到目前为止，大多数研究集中在真菌和细菌多样性与资源和寄主相关因素之间的关系，如枯木体积或树种特性。然而，我们对小气候等非生物因素如何塑造依赖木材的群落和包括分解在内的相关生态系统过程的了解还处于初级阶段。此外，对小气候条件变化的潜在适应机制还没有得到很好的理解。目前，我国森林面临着前所未有的大规模空间和地理尺度的严重气候引起的冠层萎缩，强烈地改变了森林生态系统的小气候条件。此外，森林生态系统的小气候变化也发生在常规森林管理期间，通过伐木和因此操纵树冠来实现。为了改进预测，并在气候变化时期提供缓解概念，我们需要更好地了解小气候、依赖木材的多样性和相关分解过程之间的关系。在这里，我们利用现有的大型长期枯木实验，提出了一个新的附加实验来测试与小气候对真菌和细菌群落组装机制、随后的多样性格局和相关分解过程的影响相关的假设。我们将特别使用分子方法来表征真菌和细菌群落，并了解更多关于适应机制的知识。我们的结果提供了对小气候-枯木依赖的多样性关系及其功能后果的更深层次的机械性理解，有助于森林管理概念的发展或改进，并有助于在木材生产和森林生物多样性之间找到平衡。在全球变化、气候引起的干扰事件日益频繁和严重，以及正在进行的关于气候智能林业做法的讨论中，这一点尤为重要。

Deadwood dependent fungi and bacteria are among the most species-rich groups in forests and contribute substantially to the functioning of ecosystems due to their involvement in the turnover of organic matter. So far, most studies focused on the relationship between fungal and bacterial diversity and resource and host-related factors, such as, e.g., deadwood volume or tree species identity. However, our understanding how abiotic factors like microclimate shape wood-dependent communities and related ecosystem processes including decomposition is rudimentary. Moreover, potential adaptation mechanisms to a change in microclimate conditions are not well understood. Currently, our forests face heavy climate-induced canopy dieback at an unprecedented and large spatial and geographic scale that change strongly the microclimate conditions in forest ecosystems. Furthermore, microclimate changes in forest ecosystems takes place also during regular forest management via logging and therefore manipulation of the canopy. To improve predictions and to provide mitigation concepts in times of climate change we need a better understanding on the relationship between microclimate, wood-dependent diversity and related decomposition processes. Here, we take advantage of an existing large long-term deadwood experiment and propose a novel add-on experiment to test hypotheses related to the influence of microclimate on fungal and bacterial communities assembly mechanisms, subsequent diversity pattern and related decomposition processes. We will particularly use molecular methods to characterize fungal and bacterial communities and to learn more about adaptive mechanisms. Our results provide a deeper mechanistic understanding on the microclimate-deadwood-dependent diversity relationship and its functional consequences aiding the development or improvement of forest management concepts and help to find a balance between timber production and biological diversity in forests. This is particularly important in the context of global change, the increasing frequency and severity of climate-induced disturbance events and the ongoing discussions about climate-smart forestry practices.