Dwarf-shrubs (Ericaceae) are a dominant plant functional group across the boreal, arctic, and alpine biomes, where they play important roles for biodiversity, ecology and ecosystem functioning. Despite their broad climatic and geographic ranges and dominant roles across boreal, arctic, and alpine vegetation zones, dwarf-shrub can be quite sensitive to climate changes and climate variability, as shown by their key roles in ‘arctic greening’ and ‘arctic browning’ events. This suggests that dwarf-shrubs may play a critical role in both the responses and the feedbacks between terrestrial ecosystems and the climate system.

Our DURIN project will explore the role of dwarf-shrubs in climate responses and feedbacks across biomes and habitats, integrating plant physiology, ecology, ecosystem, and climate science. Using distributed observational systems, field experiments, and growth chamber studies; we will obtain fundamental knowledge on how climate change directly and indirectly affects this important plant functional group, and it’s ecosystem functions and services. This improved process understanding will be integrated in land surface and earth system models to understand the role and contribution of dwarf-shrubs in the feedbacks from terrestrial vegetation to the climate system.

Research objectives

The primary objective of the DURIN project is to provide critical new knowledge about an important but underrepresented plant functional type in climate-biosphere science; the dwarf-shrubs of the boreal, alpine, and arctic regions, and simultaneously provide a worked example of an integrated climate response-feedback research workflow. To that end, the secondary objectives are to:

• Examine variation in dwarf-shrubs physiological and growth responses to climate, and their impacts on microclimate (WP1);
• Map important species interactions, focusing on ericoid mycorrhizae (ErM) and quantifying key roles in dwarf-shrub carbon dynamics (WP2);
• Assess how environmental factors and vegetation characteristics impact ecosystem functioning and carbon dynamics (WP3);
• Use DURIN WP0-3 outcomes to parameterize dwarf-shrubs as a new plant functional type within a terrestrial ecosystem model (WP4);
• Create optimized data workflows using transparent, reproducible Open Science practices (WP5).

My research will focus primarily on the following work packages:
WP1: Physiology and functional biology
WP1 will examine how different dwarf-shrubs vary in their physiological and growth responses to climate, and their impacts on microclimate. Using field and controlled environment experiments, WP1 will identify response- and effect traits and the influence of biotic interactions (WP2) on different facets of ecosystem carbon cycling (WP3), and inform analyses of feedbacks to climate (WP4). WP1 will focus on the controlled-climate experiments to establish causal relationships, which will be augmented with measurements in the field experiments and selected observational system sites.
Key attributes measured: plant functional traits, thermal tolerance, plant hydraulic status

WP4: Climate feedbacks: The CLM-FATES platform
In WP4 we take a terrestrial ecosystem modelling perspective, linking our insights and data from WP0-3 in order to parameterize and test a new dwarf-shrub plant functional type (PFT), and integrate it into the CLM-FATES model. We will run benchmark models against field observations at site level, and conduct model experiments exploring the role of dwarf-shrubs in both biochemical and biophysical climate feedbacks at regional and global scales.