Innovative ecosystem model shedding light on Arctic climate change
Over the last decades, the Arctic has warmed at an unprecedented rate, far more quickly than anywhere else on the planet, which has drastically affected its ecosystems. Warming-induced changes in plants and permafrost in this region can substantially affect biogenic volatile organic compound (BVOC) emissions. Released by plants and soil, BVOCs are reactive in the atmosphere and considerably affect air quality, climate and ecosystem processes. They also influence climate systems through changing atmospheric compositions. Many field and lab observations on Arctic BVOC emissions from plants and soils, however, are absent from state-of-the-art model estimates. Addressing this, the EU-funded MABVOC project, with the support of the Marie Skłodowska-Curie Actions (MSCA), incorporated BVOC dynamics, based on field observations, into a large-scale ecosystem model, LPJ-GUESS. The team applied this model to make more accurate estimates and predictions of BVOC emissions over the pan-Arctic region. “Through the project, we hoped to better understand the spatio-temporal patterns and magnitudes of BVOC emissions from the Arctic,” confirms MSCA fellow Jing Tang.
Key BVOC discoveries
“We discovered that the ongoing climatic warming alone considerably increases BVOC emissions from the Arctic,” notes project coordinator Riikka Rinnan. The project found that warming can directly increase BVOC emissions by boosting photosynthetic processes, but it can also indirectly influence the emissions’ magnitude and chemical speciation through lengthening the growing season and altering vegetation biomass and composition. “When modelled over 14 years, we realised that the direct impacts of warming increased BVOC emissions more than the indirect impacts. For the rest of this century, the future trajectory of BVOC emissions for the Arctic region is largely driven by the increasing magnitudes of temperature and atmospheric CO2 concentration,” reports Rinnan. Focusing on soil BVOCs, MABVOC carried out an extensive literature review on the current process understanding of them. From this, it summarised the sources and sinks of BVOCs between soils and the atmosphere across different ecosystems and listed the commonly reported compounds from site-level observations. The project was then able to propose a generic modelling framework to describe soil BVOC emissions in ecosystem models. This modelling framework is an important step for initiating modelling exercises on soil BVOC fluxes, which are currently not accounted for in large-scale ecosystem models. Tang notes: “The opportunity to work closely with colleagues who conduct measurements in the Arctic allowed us to link and scale site-level data to the modelled large-scale patterns. Furthermore, the framework we proposed to model soil BVOC fluxes also included the observations’ point of views and also integrated generic modelling concepts.”
The work continues
“We are at the stage of further quantifying the impacts of ecosystem BVOC emissions on atmospheric chemistry in the Arctic region, to make use of the updated emissions from this project,” concludes Tang. The project, meanwhile, will start to collect more soil BVOC measurement data, with the aim to make a process-based soil BVOC model available to better quantify and understand the role of soils in ecosystem emissions.
Keywords
MABVOC, BVOC, emissions, Arctic, soil, BVOC emissions, ecosystem model, biogenic volatile organic compound, climate warming
