Linking tree above- and belowground traits across gradients of elevation and climate in highly diverse tropical montane forests

功能特征是一种非常有用的工具：(1)描述物种和群落对其环境的反应；(2)量化单个特征或特征组合与生态系统功能的关系；(3)预测未来的物种组合及其特征谱将如何影响环境条件变化下的生态系统功能。在拟议的第二阶段，该项目将继续系统地分析高度多样化的热带山地森林树木的地上和地下特征之间的关系。采用重复抽样设计，对24种本地旱林树种的大量叶、茎、根性状进行了研究。已经预先选择了目标物种，这些物种系统地涵盖了每个海拔水平共存的植物功能类型(PFT)。此外，我们还将对不太丰富的树种(约300种)的特征进行抽样，这些树种出现在尊重小区网络中。通过森林样地调查，我们将在林分水平上量化树种丰富度及其对生物量生产的贡献，以检验我们关于热带山地森林树木功能性状随海拔和气候梯度变化的假设。在我们的研究样地中覆盖所有树种的方法将(I)提高我们对物种丰富的群落中的特征变异的理解，(Ii)改进研究组基于特征的生物地球化学通量的模拟，以及(Iii)允许得出关于热带森林中稀有树种的功能重要性的结论，这是一个以前很少讨论的主题。数据将被分析以寻找物种水平、PFT水平和林分水平上地上和地下特征之间的联系，以及种间和种内特征变异的相对重要性。在广泛调查树种的基础上，我们进一步研究了系统发育信号对性状变异的重要性。利用合作项目记录的环境协变量(土壤属性、气候)，我们将分析哪些树木响应性状对环境变化敏感，以及树木效应性状如何决定热带山地森林林分的生物量和生产力。这一分项目还负责确定REPORT所调查的样本树，并积极推动土地管理的参数化。该分项目记录的关于生物量和生产力的林分数据将用于校准土地利用结构管理。

Functional traits are a highly useful tool (i) to describe the response of species and communities to their environment, (ii) to quantify how single traits or trait combinations are related to ecosystem functioning, and (iii) to predict how future species assemblages and their trait spectrum will affect ecosystem functioning under altered environmental conditions. In the proposed second phase, the project will continue to analyse the relation between aboveground and belowground traits in trees of highly diverse tropical mountain forests in a systematic way. A large number of leaf, stem and root traits of 24 native dry forest tree species will be examined with a replicated sampling design in the RESPECT (FOR2730) plot network. Target species have been preselected which systematically cover the co-existing plant functional types (PFTs) at each elevation level. In addition, we will sample traits of less abundant-tree species (about 300 species) present in the RESPECT plot network. Through forest plot inventories, we will quantify tree species’ abundances and their contribution to biomass production on the stand level, testing our hypotheses on functional trait variation of tropical montane forest trees along elevation and climate gradients. The approach to cover all tree species in our study plots will (i) improve our understanding of trait variation in species-rich communities, (ii) improve trait-based modelling of biogeochemical fluxes in the research group, and (iii) allow conclusions on the functional importance of rare tree species in tropical forests, a topic that has rarely been addressed before.The data will be analysed for linkages between above- and belowground traits on the species-level, PFT-level and stand level, and the relative importance of interspecific and intraspecific trait variation. Based on the wide range of tree species investigated, we further examine the importance of the phylogenetic signal for trait variation. Using the environmental co-variates (soil properties, climate) recorded by cooperating projects, we will analyse which tree response traits are sensitive to environmental changes and how tree effect traits determine tropical montane forest stand biomass and productivity. This subproject is also responsible for identifying the sample trees investigated by RESPECT and it contributes actively to parameterizing the LSM. Stand-level data recorded by the subproject on biomass and productivity will be used to calibrate the LSM.