Land-use effects on patterns and processes in decomposer metacommunities in tree holes

土地利用对树洞分解元群落模式和过程的影响

• 批准号: 252088711
• 负责人: Professorin Dr. Jana Petermann
• 金额: --
• 依托单位: Leibniz-Institut zur Analyse des Biodiversitätswandels (LIB)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/252088711?language=en
• 关键词: Land; use; effects; patterns; processes

Metacommunities consist of local communities that are linked by dispersal. They have been suggested to be structured by local environmental conditions, species interactions, dispersal limitation or stochastic processes. The metacommunity concept has been used in conservation to describe the consequences of human-induced landscape fragmentation and to assess related risks to local populations. However, natural metacommunities themselves could serve as indicators of regional environmental impacts such as land-use change. Despite the recent scientific interest in the metacommunity concept and its potential importance for natural communities, it has mostly been treated theoretically or in highly artificial lab experiments. The latter have so far failed to provide conclusive evidence of the driving factors of metacommunity structure.We propose to use the platform of the Biodiversity Exploratories to study a natural metacommunity system: aquatic communities in tree holes. Protists and arthropods colonise these water-filled tree holes and decompose accumulating organic material such as dead leaves.In our research, we will focus on effects of land use on the structure and functions of tree-hole metacommunities. The Exploratories are ideally suited for this project since they provide a large number of forest plots with different management types at three sites. Our model system is a perfect plot-based system because of its relatively small natural size. It will allow us to test the effect of management on metacommunities within plots. We propose to carry out three work packages (WPs) in this project. WP1 will map tree holes and survey their aquatic communities in all forest plots of all exploratories with the aim to identify the major drivers of tree-hole characteristics, and of the structure and functioning of their communities in relation with land use. WP2 will use an experiment in selected natural tree holes to mimic changes that might arise with land-use change. Specifically, we will manipulate bottom-up and top-down forces by modifying resource input and excluding large terrestrial predators. We will measure community responses in order to quantify and mechanistically assess the influence of these changes.WP3 will set up artificial tree holes and experimentally examine community assembly processes during tree-hole colonisation in detail, additionally testing the influence of resource quality. In a collaborative project we will furthermore compare tree-hole metacommunities with forest-floor decomposer systems. We will evaluate generalities and differences to reveal the functional mechanisms behind metacommunity assembly.Upon the completion of this project, we will have contributed fundamental ecological knowledge by mechanistically describing the major drivers of tree-hole metacommunity assembly, structure and function. Furthermore, we expect to be in a better position to predict consequences of land-use change for metacommunities.

准聚居区由分散联系在一起的地方社区组成。它们被认为是由当地环境条件，物种相互作用，扩散限制或随机过程构成的。在自然保护中，准生态系统概念被用来描述人为景观破碎化的后果，并评估对当地居民的相关风险。然而，自然准湿润度本身可作为土地使用变化等区域环境影响的指标。尽管最近科学界对元生态性概念及其对自然群落的潜在重要性感兴趣，但它主要是在理论上或高度人工的实验室实验中处理的。后者迄今未能提供决定性的证据的metacrylic结构的驱动因素。我们建议使用生物多样性探索的平台，研究一个自然metacrylic系统：在树洞中的水生群落。原生生物和节肢动物在这些充满水的树洞中定居，并分解积累的有机物质，如枯叶。在我们的研究中，我们将重点关注土地利用对树洞准生态系统结构和功能的影响。探索站非常适合这个项目，因为它们在三个地点提供了大量不同管理类型的林地。我们的模型系统是一个完美的基于情节的系统，因为它的自然尺寸相对较小。这将使我们能够测试管理对地块内的准共生性的影响。我们建议在本项目中开展三个工作包（WP）。WP1将绘制树洞图，并调查所有勘探站所有林地中的水生群落，目的是确定树洞特征的主要驱动因素，以及与土地利用有关的群落结构和功能。WP2将在选定的天然树洞中进行实验，以模拟土地使用变化可能引起的变化。具体来说，我们将通过修改资源投入和排除大型陆地捕食者来操纵自下而上和自上而下的力量。我们将测量社区的反应，以量化和机械地评估这些变化的影响。WP3将设置人工树洞，并通过实验详细研究树洞殖民过程中的社区组装过程，此外还测试了资源质量的影响。在一个合作项目中，我们将进一步比较树洞与森林地面分解系统。我们将评估共性和差异，以揭示元整群组装背后的功能机制。在这个项目完成后，我们将通过机械地描述树洞元整群组装，结构和功能的主要驱动因素，贡献基础生态学知识。此外，我们希望能够更好地预测土地利用变化的后果。