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

功能性状是一个非常有用的工具(1)描述物种和群落对其环境的响应，(2)量化单个性状或性状组合与生态系统功能的关系，以及(3)预测未来物种组合及其性状谱如何在改变的环境条件下影响生态系统功能。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林树木地上和地下特征之间的关系。在RESPECT （FOR2730）样地网络中，采用重复采样设计对24种本地干林树种的大量叶、茎和根性状进行了研究。对目标物种进行了预先选择，系统地覆盖了各海拔高度共存的植物功能类型。此外，我们将对RESPECT样地网络中存在的较少丰度树种（约300种）的性状进行取样。通过样地调查，我们将在林分水平上量化树种丰度及其对生物量生产的贡献，验证我们关于热带山地森林树木功能性状沿海拔和气候梯度变化的假设。在我们的研究地块中覆盖所有树种的方法将(i)提高我们对物种丰富群落中性状变化的理解，（ii）改进研究小组中基于性状的生物地球化学通量建模，以及（iii）允许对热带森林中稀有树种的功能重要性得出结论，这是一个以前很少涉及的主题。分析了地上、地下性状在种、林分和林分水平上的联系，以及种间和种内性状变异的相对重要性。基于所调查树种的广泛范围，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（土壤性质、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林分生物量和生产力。该子项目还负责识别RESPECT调查的样本树，并对LSM的参数化做出积极贡献。生物量和生产力子项目记录的林分水平数据将用于校准LSM。

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.