Tackling trade-offs? Understanding how trait coordination for drought- and shade-tolerance regulates seedling dynamics in fragmented wet tropical forests

解决权衡问题？

• 批准号: 445495809
• 负责人: Professorin Dr. Bettina M.J. Engelbrecht
• 金额: --
• 依托单位: Department of Biotechnology
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/445495809?language=en
• 关键词: Tackling; trade; offs; Understanding; how

Tropical forests house over a third of Earth’s biodiversity and play a critical role as global carbon sinks, but stand threatened by climate change and fragmentation due to human land-use. It is therefore an urgent concern to disentangle the mechanisms by which fragmentation alters tropical forest dynamics in a drought-prone future climate. The coordination of plant tolerance to multiple stresses is a fundamental question in ecology with pervasive consequences for species distributions, community composition and ecosystem function. Two long-standing conflicting hypotheses propose that tolerance to drought and shade - two key dimensions of plant performance - correlate positively (synergy hypothesis) or trade-off (trade-off hypothesis). A third possibility is that shade and drought responses are independent (independence hypothesis). Results concerning the coordination of drought- and shade-tolerance remain conflicting.In this proposed research, our overarching goal is to provide fundamental insights into how the coordination of drought- and shade-tolerance influences seedling dynamics in wet tropical forests subject to global change. Specifically, we aim to understand (1) edge effects on light and water availability in fragmented forests, (2) how gradients of light and water availability correlate with seedling distributions and community composition, (3) interspecific variation in seedling performance (survival and growth) responses to light and water availability, (4) the trait-based mechanisms underlying seedling responses to water and light availability, and (5) the coordination between drought- and shade-tolerance of species and its consequences for regeneration dynamics of fragmented forests in a changing climate.Our fully integrated Indo-German work programme will be conducted in a human-modified forest complex in the central Western Ghats (India). We will combine observational and experimental approaches to integrate detailed characterizations of microsite conditions and assessment of seedling performance and community composition in a network of seedling plots, with comparative assessments of 18 relevant physiological, anatomical and morphological functional traits for seedlings of 25-30 tree species. This unprecedented data set will allow for a cutting-edge evaluation of the coordination of species drought- and shade-tolerance and its consequences for forest regeneration. Overall, our study will address fundamental knowledge gaps in trait-based ecology, advance our understanding of forest response to global change, and generate science-based inputs for restoration efforts geared towards supporting vulnerable species or selecting species that can mitigate the impacts of global change on biodiverse tropical forests.

热带森林拥有地球三分之一以上的生物多样性，作为全球碳汇发挥着关键作用，但由于人类土地使用造成的气候变化和破碎化，热带森林面临着威胁。因此，迫切需要弄清在未来易发生干旱的气候中，破碎化改变热带森林动态的机制。 植物对多种胁迫的耐受性协调是生态学中的一个基本问题，对物种分布、群落组成和生态系统功能具有广泛的影响。两个长期存在的相互矛盾的假说提出，耐旱性和遮荫-植物性能的两个关键方面-正相关（协同假说）或权衡（权衡假说）。第三种可能性是，遮荫和干旱的反应是独立的（独立性假设）。关于干旱和耐荫性的协调结果仍然conflict.In这项拟议的研究，我们的总体目标是提供基本的见解干旱和耐荫性的协调如何影响幼苗动态在潮湿的热带森林受到全球变化。具体而言，我们的目标是了解（1）破碎森林中光和水可用性的边缘效应，（2）光和水可用性梯度如何与幼苗分布和群落组成相关，（3）幼苗性能的种间差异（4）幼苗对水分和光照响应的基于性状的机制，以及（5）物种耐旱性和耐阴性之间的协调及其对气候变化中破碎森林再生动态的影响。我们的完全一体化的印度-德国工作方案将在西高止山脉中部（印度）的一个人为改造的森林综合体中进行。我们将结合联合收割机的观察和实验方法，以集成详细的微立地条件和幼苗性能和社区组成的评估网络中的苗木小区，18个相关的生理，解剖和形态功能性状的比较评估25-30树种的幼苗。这一前所未有的数据集将有助于对物种耐旱性和耐荫性的协调及其对森林再生的影响进行最前沿的评价。总体而言，我们的研究将解决基于特征的生态学的基本知识差距，推进我们对森林应对全球变化的理解，并为恢复工作提供科学投入，以支持脆弱物种或选择能够减轻全球变化对生物多样性热带森林影响的物种。