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

拉丁美洲的森林覆盖着从热带到南半球高纬度的很大的纬度和气候梯度。因此，非洲大陆拥有各种各样的森林类型，包括亚马逊--世界上最大的热带森林--以及集中在沿海的各种大西洋森林，智利和阿根廷的温带森林，以及瓦尔迪亚的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中心，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%的陆地动植物物种的家园，并储存了全球很大一部分有机碳。热点。其中一些拉丁美洲的森林仍然覆盖着其原始(哥伦比亚之前)范围的很大一部分：亚马逊仍然覆盖了大约500万平方公里，是其原始面积的80%。然而，其他地区，如大西洋森林，几乎已经消失，现在严重支离破碎。温带森林也在缩小，尽管努力阻止进一步的砍伐。然而，经济发展、人口增加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。当地的压力来源通常来自持续发展、选择性采伐、猎杀较大的鸟类和哺乳动物、过度开发宝贵的棕榈果等关键森林资源、采矿和/或将森林转化为农业用途。全球环境驱动因素源于全球变暖的气候。然而，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构成，也不清楚人类影响--例如在高度分散的森林景观中缺乏分散者或超过物种容忍限度的气候条件--与森林植物的社区一级反应之间是否存在阈值。我们的目标是调查这一点，支持制定能够保护这些森林的多样性及其功能的战略。我们要做到这一点，需要调查这些森林的多样性与功能之间的关系；探索森林使用压力和气候变化造成的功能是否存在门槛；通过实验测试应对措施；以及将预测能力推广到大范围。Arboles的目标是通过将现有的森林调查方法与尖端的功能特征、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特征相结合，这将使我们能够在当地人类干扰以及气候和大气组成变化的情况下表征状态和随时间的变化。我们将沿着以下轴线重点研究性状：(I)衡量结构投资(如木材密度、单位面积叶质量、最大高度)的生活史战略，(Ii)对生产器官(如叶片营养物质)的投资，(Iii)对生殖器官的投资，(Iv)对水分胁迫和高温胁迫的耐受性。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，将首次对人类如何影响拉丁美洲的森林进行跨洲评估。

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.