Classification of Tree Functional Types in a Megadiverse Tropical Mountain Forest from Leaf Optical Metrics and Functional Traits for Two Related Ecosystem Functions

Forests

Nina Farwig¹  Andreas Fries²  Katja Trachte³  Franz Pucha-Cofrep³  Oliver Limberger⁴  Jörg Bendix⁴  Jürgen Homeier⁵  Christoph Leuschner⁵ 

[1] Conservation Ecology, Department of Biology, University of Marburg, Karl-von-Frisch-Straße 8, 35043 Marburg, Germany;Department of Geology and Mine and Civil Engineering (DGMIC), Universidad Técnica Particular de Loja, San Cayetano Alto s/n, Loja 1101608, Ecuador;Institute for Environmental Sciences, Brandenburg University of Technology (BTU) Cottbus-Senftenberg, 03046 Cottbus, Germany;Laboratory for Climatology and Remote Sensing (LCRS), Department of Geography, University of Marburg, Deutschhausstraße 12, 35037 Marburg, Germany;Plant Ecology and Ecosystems Research, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany;

关键词: ecosystem productivity;    energy fluxes;    leaf hyperspectra;    functional traits;    tree functional types;    tropical forest;   

DOI  :  10.3390/f12050649

来源: DOAJ

【 摘 要 】

Few plant functional types (PFTs) with fixed average traits are used in land surface models (LSMs) to consider feedback between vegetation and the changing atmosphere. It is uncertain if highly diverse vegetation requires more local PFTs. Here, we analyzed how 52 tree species of a megadiverse mountain rain forest separate into local tree functional types (TFTs) for two functions: biomass production and solar radiation partitioning. We derived optical trait indicators (OTIs) by relating leaf optical metrics and functional traits through factor analysis. We distinguished four OTIs explaining 38%, 21%, 15%, and 12% of the variance, of which two were considered important for biomass production and four for solar radiation partitioning. The clustering of species-specific OTI values resulted in seven and eight TFTs for the two functions, respectively. The first TFT ensemble (P-TFTs) represented a transition from low to high productive types. The P-TFT were separated with a fair average silhouette width of 0.41 and differed markedly in their main trait related to productivity, Specific Leaf Area (SLA), in a range between 43.6 to 128.2 (cm²/g). The second delineates low and high reflective types (E-TFTs), were subdivided by different levels of visible (VIS) and near-infrared (NIR) albedo. The E-TFTs were separated with an average silhouette width of 0.28 and primarily defined by their VIS/NIR albedo. The eight TFT revealed an especially pronounced range in NIR reflectance of 5.9% (VIS 2.8%), which is important for ecosystem radiation partitioning. Both TFT sets were grouped along elevation, modified by local edaphic gradients and species-specific traits. The VIS and NIR albedo were related to altitude and structural leaf traits (SLA), with NIR albedo showing more complex associations with biochemical traits and leaf water. The TFTs will support LSM simulations used to analyze the functioning of mountain rainforests under climate change.

【 授权许可】

Unknown