Contact person: Kirsten Thonicke
Flagship activity: Ecosystem stability and dynamics
In an interdisciplinary effort we projected the relative role of climate and land-use change for biome shifts on the South American continent over the 21st century (Boit et al. 2016). We specifically highlight how climate change can overtake land-use change and become the most important driver of biome shifts depending on the socio-economic pathway humanity will follow in the future. To assess the role of biodiversity for the resilience of South America’s natural vegetation against projected climatic pressures we developed a new subversion of the dynamic global vegetation model LPJmL (Lund-Potsdam-Jena managed Land), we call LPJmL-FIT where “FIT” stands for “Flexible Individual Traits”. This model aims to overcome the approach of representing natural vegetation with plant functional types (PFT) by simulating individual trees and diversifying several important plant parameters within their globally occurring ranges (Sakschewski et al. 2015). This approach allows for ecological filtering and testing for effects of functional diversity on ecosystem resilience. We this model we showed how functional diversity can increase the resilience of Amazon rainforest under climate change (Sakschewski et al. 2016).
Simulated rainforest biomass under climate change and different plant trait diversity. Annual biomass over 800 simulation years for 400 ha of Ecuadorian rainforest from three different versions of the vegetation model LPJmL under a severe climate change scenario (RCP 8.5 HadGEM2). ∆T: annual temperature difference to the mean temperature of pre-impact time (1971–2000) in K. Black line: Biomass of standard LPJmL based on 2 tropical plant functional types (PFTs). Blue line: Biomass of LPJmL with individual trees and enhanced functional diversity (default LPJmL-FIT). Red line: Biomass of LPJmL with individual trees and the same PFTs as standard LPJmL (low diversity LPJmL-FIT). Only default LPJmL-FIT with high functional diversity shows biomass recovery. For further information please see the original publication under https://www.nature.com/articles/nclimate3109.
Forest height structure recovers with biomass while tree traits are adjusting to climate change. a, Mean biomass contribution of tree height classes for pre-, mid- and post-impact time (Methods). b, Visualization of model output (also see link to Video) showing 0.5 ha of the 400 ha of Ecuadorian rainforest in a selected year during pre-, mid-, and post-impact time, respectively (top to bottom). Different crown (stem) colours denote different SLA (WD) values of individual trees. These plant traits show a clear shift over time as an adjustment to climate change which in return leads to the simulated biomass recovery. Crown size, stem diameter and tree height are scaled by model output. Green squares indicate tree gaps covered by herbaceous plants. For further information please see the original publication under https://www.nature.com/articles/nclimate3109.
Link to video: Supplementary Video
Link to project database: Robin
