BIODIVERSITY AND LAND-USE IMPACTS ON TROPICAL ECOSYSTEM FUNCTION (BALI)

热带地区的人为干扰和土地利用变化正在导致生物多样性的不可逆转的变化和生态系统地球化学的重大变化。然而，我们仍然对人类驱动的生物多样性变化如何反馈改变生物地球化学过程缺乏了解。这一知识差距大大限制了我们模拟和预测热带生态系统对当前和未来环境变化的反应的能力。在我们理解生物多样性的变化如何改变热带地区的生态系统过程方面，存在着一些关键挑战，即：（i）热带的高度分类多样性如何与生态系统功能联系在一起，（ii）干扰后营养级和分类类群之间的相互作用的变化如何影响功能多样性和生态地球化学，以及（iii）如何使用地块级测量来缩放到整个景观。我们已经成立了一个联盟，以应对这些关键挑战，启动一项大规模，可复制和完全集成的研究，汇集了一个具有技能和专业知识的多学科团队，以研究必要的分类和营养组，不同的生物地球化学过程，以及它们之间复杂的相互作用。为了理解和量化土地的影响-利用重点生物多样性群体活动的变化及其对地球化学的影响，我们将：㈠分析关于重点生物多样性群体分布的现有数据;（ii）在改变的森林生态系统的稳定性项目现场对小规模处理进行取样（处理方法包括森林退化、破碎化、油棕榈转换）和关键辅助地点（Maliau盆地-贫瘠土壤上的古老植物，Lambir丘陵-肥沃土壤上的古老植物，沙巴生物多样性实验-恢复森林，INFAPRO-FACE -恢复森林）;以及（iii）实施新的实验，控制生物多样性的关键组成部分和地下碳通量的路径。操作将集中于树木和藤本植物、菌根真菌、白蚁和蚂蚁，因为这些生物体可能是人类改造的热带森林中生物地球化学循环的变化因素。我们将使用尖端技术的组合来测试这些目标生物群如何相互作用，以影响生物地球化学循环。此外，我们还将整理和分析其他分类群的存档数据，包括具有保护意义的脊椎动物。关键的统一概念是认识到所谓的“功能性状”在将分类多样性与生态系统功能联系起来方面发挥着关键作用。我们将专注于识别与植物相关的关键功能性状，以及它们如何在SAFE沿沿着干扰梯度丰富变化。特别是，我们提出，叶片功能性状（如物理和化学吸收，氮含量等），在决定关键生态系统进程方面发挥关键作用，并对大气成分产生重大影响。最重要的是，先进的航空遥感技术表明，有可能绘制叶功能性状，化学和生理学在小尺度，所以我们将使用这些新的航空方法来量化森林退化，冠层结构，生态地球化学循环和树木分布的小尺度模式。基于过程的数学模型，然后将链接到遥感图像和功能多样性和地球化学循环的地面测量，以扩大我们的调查结果的干扰梯度。

Anthropogenic disturbance and land-use change in the tropics is leading to irrevocable changes in biodiversity and substantial shifts in ecosystem biogeochemistry. Yet, we still have a poor understanding of how human-driven changes in biodiversity feed back to alter biogeochemical processes. This knowledge gap substantially restricts our ability to model and predict the response of tropical ecosystems to current and future environmental change. There are a number of critical challenges to our understanding of how changes in biodiversity may alter ecosystem processes in the tropics; namely: (i) how the high taxonomic diversity of the tropics is linked to ecosystem functioning, (ii) how changes in the interactions among trophic levels and taxonomic groups following disturbance impacts upon functional diversity and biogeochemistry, and (iii) how plot-level measurements can be used to scale to whole landscapes. We have formed a consortium to address these critical challenges to launch a large-scale, replicated, and fully integrated study that brings together a multi-disciplinary team with the skills and expertise to study the necessary taxonomic and trophic groups, different biogeochemical processes, and the complex interactions amongst them.To understand and quantify the effects of land-use change on the activity of focal biodiversity groups and how this impacts biogeochemistry, we will: (i) analyse pre-existing data on distributions of focal biodiversity groups; (ii) sample the landscape-scale treatments at the Stability of Altered Forest Ecosystems (SAFE) Project site (treatments include forest degradation, fragmentation, oil palm conversion) and key auxiliary sites (Maliau Basin - old growth on infertile soils, Lambir Hills - old growth on fertile soils, Sabah Biodiversity Experiment - rehabilitated forest, INFAPRO-FACE - rehabilitated forest); and (iii) implement new experiments that manipulate key components of biodiversity and pathways of belowground carbon flux. The manipulations will focus on trees and lianas, mycorrhizal fungi, termites and ants, because these organisms are the likely agents of change for biogeochemical cycling in human-modified tropical forests. We will use a combination of cutting-edge techniques to test how these target groups of organisms interact each other to affect biogeochemical cycling. We will additionally collate and analyse archived data on other taxa, including vertebrates of conservation concern. The key unifying concept is the recognition that so-called 'functional traits' play a key role in linking taxonomic diversity to ecosystem function. We will focus on identifying key functional traits associated with plants, and how they vary in abundance along the disturbance gradient at SAFE. In particular, we propose that leaf functional traits (e.g. physical and chemical recalcitrance, nitrogen content, etc.) play a pivotal role in determining key ecosystem processes and also strongly influence atmospheric composition. Critically, cutting-edge airborne remote sensing techniques suggest it is possible to map leaf functional traits, chemistry and physiology at landscape-scales, and so we will use these novel airborne methods to quantify landscape-scale patterns of forest degradation, canopy structure, biogeochemical cycling and tree distributions. Process-based mathematical models will then be linked to the remote sensing imagery and ground-based measurements of functional diversity and biogeochemical cycling to upscale our findings over disturbance gradients.