The Arctic experiences amplified warming and increased heatwaves. It is essential to understand how plants respond to these changes and alter their climate impacts. Through closely collaborating with many experimentalists and empiricists, we have added a variety of observation-based relationships into the process-based dynamic vegetation model, LPJ-GUESS.  We explore 

1. how climate change has and will alter greenhouse gas (i.e., CO2 and CH4) and BVOC emissions, see examples:  Tang et al., 2015, Tang et al., 2016, and Rinnan et al., 2021

2. how climate-induced vegetation changes can chemically influence our climate, see Tang et al., 2023

3. how plant temperature differing from air temperature influences plant responses, see Tang et al., 2024;

Global efforts of improving air quality have and will largely reduce black carbon, and sulfur emissions transported to the Arctic. In cleaner arctic air with expected more local anthropogenic activities, such as shipping and pipelines, we expect more significant contribution from point sources of ship routes into clearer air. We all know the Arctic is warming faster than the global average, meaning more vegetation can start to grow in the colder region. 

The DFF-funded project will investigate climatic feedback mechanisms from a greener, more navigable Arctic by focusing on short-lived climate forces including VOCs, aerosol from natural and anthropogenic emissions. The main tools are process-based models. We want to explore the interactive roles of increasing shipping activities, biogenic vegetation, and oceanic emissions in impacting the Arctic climate. 

(more to come, this project will run from 2025-2028) 

Dissolved matters are the decomposition product of plant and soil materials. Once these organic and inorganic matter entered water bodies, they can be decomposed by microbes and release greenhouse gases back to the atmosphere, and small fractions become sediments.  Accurately representing both biotic and abiotic processes in influencing the concentration of dissolved matters is an important step in connecting land and water biogeochemical processes. I have extended LPJ-GUESS with detailed soil DOC processes (see Tang et al., 2018).

Another area of my focus is related to modelling soil BVOC dynamics. Soils can act as sources and sinks of BVOCs (see my review article Tang et al., 2019). Currently, both the source and sink processes have not yet been considered in ecosystem models. We have extracted data from the published papers, and are working on identifying emission response curves and ultimately modelling soil BVOC emissions with the dependence of material origins and environmental variables.

Dynamic vegetation models often ignore water communications throughout the landscape, which potentially lead to uncertainties in simulated water and carbon fluxes. We are interested in connecting the simulated spatial units (e.g., gridcells) based on topographical information (see Tang et al., 2014 a, b)and representing landscape topology in the model (ongoing PhD project).