Drivers of recruitment and diversity in symbioses: Assessing changes in fungal, algal, and bacterial communities of the lichen holobiont along land use gradients

物种间的相互作用会受到人为干扰的影响，例如森林管理。森林特征可以影响当地的生物多样性，并在生物相互作用中发挥生态过滤器的作用。了解这些动态变化对于预测当代生态群落对土地利用变化的响应具有重要意义。在这方面，多物种全息菌，如地衣，是有价值的研究系统，因为它们将包括真菌、藻类和细菌在内的各种微生物群落紧密地结合在一起。然而，目前尚不清楚完整地衣如何从环境微生物池中召唤其多样性；以及地衣共生如何调节单个完整生物成分的特定环境反应。在这里，我们解决的问题是：环境微生物池和地衣全息菌是如何相互作用的？完整地衣的个别成分及其与环境微生物池的相互作用如何应对森林管理的变化？我们将调查在地衣中发现的微生物多样性在多大程度上嵌套在邻近的环境池中(即树皮和土壤中)。然后，我们将使用生物多样性探索实验室的所有150个森林EP地块，模拟不同森林管理强度下多样性和生物相互作用的变化。总体而言，该项目将深入了解微生物补充到地衣共生中的机制和反馈。它将进一步阐明管理做法在推动森林中不同微生物群体之间生物相互作用的频率和稳定性方面的作用。

Species interactions are subject to anthropogenic disturbances such as forest management. Forest features can impact local biodiversity and act as ecological filters on biotic interactions. Understanding these dynamics is important for predicting contemporary responses of ecological communities to land use change. Multi-species holobionts, such as lichens, are valuable study systems in this regard, because they closely band together diverse microorganismal communities including fungi, algae, and bacteria. However, it is yet unclear how the lichen holobiont summons its diversity from environmental pools of microorganisms; and how the lichen symbiosis may modulate specific environmental responses of individual holobiont components. Here we address the questions: How do environmental pools of microorganisms and the lichen holobiont interact? How do individual components of the lichen holobiont and their interactions with environmental microorganismal pools respond to changes in forest management? We will investigate the degree to which microorganismal diversity found in the lichen holobiont is nested within that of adjacent environmental pools (i.e. on bark and in soil). We will then model changes in diversity and biotic interactions under different levels of forest management intensity using all 150 forest EP plots of the Biodiversity Exploratories. Overall, this project will deliver insights into mechanisms and feedbacks characterizing recruitment of microorganisms into the lichen symbiosis. It will further shed light on the role of management practices in driving frequency and stability of biotic interactions among different microorganismal groups in forests.