A new implementation of dwarf-shrub plant functional type within the CLM-FATES land-surface model

Ericaceous dwarf-shrubs are a key actor of the boreal, arctic and alpine biomes in which they are locally dominant and extensively spread, affecting biodiversity, ecology and ecosystem functioning. In particular, they play  significant roles in ecosystem carbon sequestration and long-term storage through interactions with belowground fungal networks. These effects may have an important influence on feedback mechanisms between terrestrial ecosystems and the global climate system. This role may be noticeably affected by climate change. However, the dwarf-shrub interactions with climate are still poorly understood, and this plant functional type is currently underrepresented in climate-biosphere science.  

The objective of the DURIN project is to explore the role of dwarf-shrubs in climate responses and feedbacks across biomes and habitats in Norway, and to provide new insight on the direct and indirect effects of climate change on this plant functional type and its ecosystem functions and services. Land-surface models offer a particularly convenient framework to explore and quantify the complexity of the relationship between the climate system and dwarf-shrub plant functional type, as well as the impacts of climate change on related ecosystems across Norway.  

As part of this project, we propose here to implement dwarf-shrub plant functional type within the Community Land Model (CLM) coupled with the Ecosystem Demography model FATES (Functionally Assembled Terrestrial Ecosystem Simulator). By taking advantage of the enhanced understanding achieved through the other work packages of the project, we will first parametrize the new plant functional type and integrate it into the CLM-FATES model. We will use the field observations from the other work packages to calibrate the CLM-FATES model at site-level across environmental gradients of temperature, precipitation and light availability. Using the new implementation of dwarf-shrubs into the CLM-FATES model, we will ultimately assess the role of dwarf-shrubs in both biochemical and biophysical climate feedbacks.