WarmTraits · How does climate warming duration affect above- and belowground plant traits and overall tundra ecosystem functionality?

How does climate warming duration affect above- and belowground plant traits and overall tundra ecosystem functionality?

In the Arctic, climate change is causing tundra landscapes to warm at a rate twice that of the rest of the world. A key objective in ecology is to predict how climate warming will alter plant communities and to measure its impact on the ecosystem. Plant functional traits, such as plant height or leaf size, are measurable characteristics that reveal various strategies for competition with other plants and adaptation to climate change. For instance, variations in leaf thickness or nitrogen content have a significant influence on the carbon balance within ecosystems by directly affecting photosynthetic carbon uptake and the rates of microbial litter decomposition. As a result, plant traits establish a quantifiable connection between changes in vegetation and ecosystem processes that, in turn, have implications for the climate. As the tundra heats up, the vegetation absorbs more carbon dioxide through photosynthesis while microbial decomposition of soil carbon increasingly releases greenhouse gases into the atmosphere. Permafrost soils hold twice as much carbon as is currently present in the atmosphere. This raises significant concern regarding whether the tundra biome will act as net source or sink of atmospheric carbon, and consequently, whether it will exacerbate or mitigate future climate change. Ultimately, this hinges on the balance between plant carbon uptake and soil microbial decomposition losses. However, plants play a dual role—they not only sequester carbon but also regulate decomposition rates through changes in their leaf and root traits. Nevertheless, our understanding of how plants respond to long-term tundra warming in terms of their functional traits remains limited. In this project, my aim is to quantify the impact of climate warming duration on a comprehensive set of plant functional traits, both above- and belowground. To achieve this, I will take advantage of a unique opportunity to collect samples from a long-term field experiment. In this experiment, mini-greenhouses have been warming arctic tundra plots for durations of two, 12, and 22 years, respectively. Additionally, I will examine how plant responses to warming influence essential ecosystem functions, such as carbon and nitrogen mineralization rates, using stable isotopic labelling techniques. To enhance the project's impact, I plan to organize and host a field workshop. This workshop will not only educate students in the field of trait-based functional ecology but also provide them with valuable hands-on experience in field research methodologies. In doing so, I aim to efficiently collect project data while offering students invaluable research exposure and skill development. This project enhances our mechanistic understanding of how tundra ecosystems respond to prolonged climate warming, carrying direct implications for their feedback into the global climate system. The findings will assist researchers and modelers in refining climate change predictions, ultimately benefiting us all.

Data: CORDIS, © European Union