ARBOLES: A trait-based Understanding of LATAM Forest Biodiversity and Resilience

拉丁美洲森林覆盖了很大的纬度和气候梯度，从热带延伸到南半球高纬度地区。因此，该大陆拥有各种各样的森林类型，包括亚马逊雨林——世界上最大的热带森林——以及沿海岸集中的各种大西洋森林、智利和阿根廷的温带森林以及瓦尔迪维亚的寒冷雨林和巴塔哥尼亚的诺索法格斯森林。这些森林是全球生物多样性的震中，包括几个热带和热带外生物多样性热点。例如，亚马逊雨林是约10%的陆生动植物物种的家园，并储存了全球有机碳的很大一部分。热点。其中一些拉丁美洲森林仍然覆盖着其原始（前哥伦比亚）范围的很大一部分：亚马逊森林仍然覆盖着大约500万平方公里，这是其原始面积的80%。然而，其他的，如大西洋森林，几乎消失了，现在严重破碎。温带森林也在萎缩，尽管人们努力阻止进一步的减少。然而，经济发展、人口增长和全球环境变化驱动因素的增长意味着所有森林现在都面临着强大的人为压力。局部压力源通常来自持续的开发、选择性砍伐、大型鸟类和哺乳动物的狩猎、对重要森林资源（如宝贵的棕榈果实）的过度开发、采矿和/或将森林转为农业用途。全球环境驱动因素源于全球气候变暖。然而，目前尚不清楚这些地方压力和不断变化的环境条件将如何改变拉丁美洲森林的组成，也不清楚在人类影响（例如在严重破碎的森林景观或超过物种容忍极限的气候条件中缺乏分散物）与森林植物的群落级反应之间是否存在阈值。我们的目标是对此进行调查，支持制定能够保护这些森林的多样性及其功能的战略。我们通过调查这些森林的多样性和功能之间的关系来实现这一目标；探索是否存在由森林利用压力和气候变化造成的功能阈值；通过实验测试反应；通过将预测能力推广到大范围。ARBOLES旨在通过将现有的森林清查方法与尖端的功能性状、基因组学、实验和遥感方法相结合来实现这些目标。我们的方法包括将森林地块与植物性状相结合，这将使我们能够在面对当地人类干扰和气候和大气成分变化的情况下描述状态和变化。我们将沿着以下轴关注性状：(i)衡量结构投资（如木材密度、每面积叶质量、最大高度）的生活史策略，（ii）生产器官投资（如叶片营养），（iii）生殖器官投资，（iv）对水分胁迫和热胁迫的耐受性。这项工作是与阿根廷、巴西、智利和秘鲁的研究小组合作进行的，它将提供关于人类如何影响拉丁美洲森林的第一个跨大陆评估。

Latin American forests cover a very large latitudinal and climate gradient extending from the tropics to Southern hemisphere high latitudes. The continent therefore hosts a large variety of forest types including the Amazon - the world's largest tropical forest - as well as the diverse Atlantic forests concentrated along the coast, temperate forests in Chile and Argentina as well as the cold rainforests of Valdivia and the Nothofagus forests of Patagonia. These forests are global epicentres of biological diversity and include several tropical and extra-tropical biodiversity hotspots. For example, the Amazon rainforest is home to ~10% of terrestrial plant and animal species and store a large fraction of global organic carbon. hotspots. Some of these Latin American forests still cover a large fraction of their original (pre-colombian) extent: the Amazon still covers approximately 5 Million km2, which is 80% of its original area. However, others, such as the Atlantic forest, have nearly disappeared and are now heavily fragmented. Temperate forests have also shrunk, despite efforts to halt further reduction. However, economic development, population rises and the growth in global drivers of environmental change mean that all forests now face strong anthropogenic pressures. Locally stressors generally result from ongoing development, selective logging, the hunting of larger birds and mammals, over-exploitation of key forest resources such as valuable palm fruits, mining, and/or forest conversion for agricultural use. Global environmental drivers stem from the world's warming climate. Yet it is not clear how these local pressures and changing environmental conditions will alter the composition of Latin American forests, and whether there are thresholds between human impacts - such as the lack of dispersers in heavily fragmented forest landscapes or climate conditions exceeding limits of species tolerance - and the community level responses of forest plants. We aim to investigate this, supporting the development of strategies that can preserve the diversity of these forests and their functioning. We achieve this by investigating the relationships between diversity and functioning of these forests; exploring whether there are thresholds in functioning resulting both from pressures of forest use and changing climate; by experimentally testing responses; and by generalizing predictive capability to large scales. ARBOLES aims to achieve these goals by integrating established forest inventory approaches with cutting-edge functional trait, genomics, experimental and remote sensing approaches.Our approach involves combining forest plots with plant traits, which will enable us to characterize state and shifts over time in the face of local human disturbance and changing climate and atmospheric composition. We will focus on traits along the following axes: (i) life-history strategies measuring investment in structure (like wood density, leaf mass per area, maximum height), (ii) investment in productive organs (like leaf nutrients), (iii) investment in reproductive organs, (iv) tolerance to water stress and heat stress. The work is being conducted in collaboration with research groups in Argentina, Brazil, Chile and Peru - and will provide a first cross-continent assessment of how humans are influencing Latin American forests.