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

物种间的相互作用受到人为干扰，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。了解这些动态对于预测生态群落对土地利用变化的当代反应非常重要。多物种全息生物，如地衣，在这方面是有价值的研究系统，因为它们紧密地结合了不同的微生物群落，包括真菌、藻类和细菌。然而，目前尚不清楚地衣全息生物是如何从环境微生物池中召唤其多样性的；以及地衣共生如何调节个体全息生物组分的特定环境反应。在这里，我们解决的问题是：微生物和地衣全息生物的环境池如何相互作用？地衣全息生物的各个组成部分及其与环境微生物池的相互作用如何响应森林管理的变化？我们将调查在地衣全息生物中发现的微生物多样性在邻近环境池（即树皮和土壤）中嵌套的程度。然后，我们将利用生物多样性探索的所有150个森林EP样地，模拟不同森林管理强度下的多样性和生物相互作用的变化。总体而言，该项目将提供对地衣共生中微生物招募的机制和反馈特征的见解。它将进一步阐明管理实践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.