B2 Tree physiological and structural properties as response and effect traits of bioticatmospheric interactions in natural and anthropogenic eco-systems in South Ecuador [funded by DFG]
PI(s) for this project:
Prof. Dr. Dr. h.c. Erwin Beck
Prof. Dr. Achim Bräuning
Subproject B2 addresses the response and effect traits of the two target functions, latent heat flux (evapotranspiration) and biomass production, by which RESPECT (FOR7230) will explain ecosystem changes through climate and land use change. Data contribution to the joint endeavor is on the level of plant functional types (PFTs) selected along altitudinal, successional and land use gradients in the South Ecuadorian Andes.
The project aims at a comprehensive characterization of process-based functional traits of water and carbon relations and of biomass production of trees in a tropical mountain rainforest, and of other PFTs on the anthropogenic systems, mainly pastures. In the scope of the physiological characterization of the PFTs representing subsequent successional stages of the forest, the focus of the study is on the identification of hydraulic types of trees. The relation of iso- and anisohydric PFTs on the study plots along the gradients shall be investigated with direct measurements of the water potential and turgor on the highly instrumented plots and corresponding structural traits on all plots.
Simultaneous measurements of diurnal stem diameter variations, sap flow and gas exchange will allow a sound quantification of plant water and carbon relations. Dual measurements of stable carbon and oxygen isotopes in the cellulose of leaves and wood will link the different tree compartments and help to characterize variations in the interplay of photosynthesis, transpiration, and growth. Isotope signatures collected under different weather conditions and along radial increment cores of trees will reveal the plasticity of functional traits, as well as the resistance of trait inter-relationships to varying environmental conditions and during tree ontogeny.
On the anthropogenic systems, we will focus on the dependence of the competitive strength of pasture crops and weeds on environmental variables. The collected data on traits, functional trait diversity, and co-variates are of basic relevance to parameterize and supplement the LSMs developed within FOR7230, especially LSMBio and LSMatmo.