The future of the tundra
- Reference number
- FFL21-0194
- Project leader
- Bjorkman, Anne
- Start and end dates
- 220801-271231
- Amount granted
- 15 000 000 SEK
- Administrative organization
- Göteborg University
- Research area
- Life Sciences
Summary
This research will identify the consequences of warming-driven vegetation change for the functioning of Arctic ecosystems and feedbacks to the global climate system. The Arctic is the fastest-warming region on Earth, and Arctic soils contain more than double the amount of carbon currently in the atmosphere. Changes in the vegetation can influence whether this carbon is released into the atmosphere, thus contributing to additional climate warming, but our understanding of this potential is still poor. My research will: 1) quantify the relationships between plant traits and key ecosystem processes related to global carbon cycling: litter decomposability, plant productivity, and flammability, using field and laboratory experiments, 2) predict the rate with which these traits are likely to change in response to warming by identifying the relative contribution of phenotypic plasticity and genetic differentiation to trait variability, and 3) determine the contribution of Arctic vegetation change to global-scale vegetation-climate feedbacks by combining knowledge from aims 1 and 2 with multi-decadal records of vegetation change and responses to experimental warming at hundreds of locations across the Arctic. The knowledge generated by this project will allow us to understand how vegetation influences carbon cycling in tundra ecosystems and improve our ability to project future shifts in Arctic ecosystem functioning as a result of warming-driven vegetation change.
Popular science description
The current rapid warming of Earth’s surface is unprecedented in the last 100,000 years. It is perhaps science’s greatest challenge to understand what this means for life on earth; how will such rapid change affect the ecosystem functions and services that nature contributes to people? This question is particularly urgent in the Arctic, where warming is happening three times faster than anywhere else on the planet. The frozen soils of the Arctic hold more than double the carbon that is currently in the atmosphere; if this carbon is released it could contribute to substantial additional warming over the entire globe. Therefore, the changes caused by climate warming in the Arctic can influence the entire planet. A critically important key to understanding what will happen to Arctic carbon lies in the plants that grow there. Characteristics of the vegetation, for example how tall it grows, how dense the stems are, or how long the leaves remain green, can influence many ecosystem functions and processes, including how carbon moves through the ecosystem. Changes in the vegetation due to climate warming can thus influence whether Arctic carbon will remain stored in soils or will be released into the atmosphere. I will identify specific, easily-measurable characteristics of plants, known as plant traits, that directly influence several important ecosystem processes. I will focus on three key processes that influence carbon cycling: (1) the decomposition of dead plant material (litter), which determines whether the carbon in plant leaves and stems is stored as soil or decomposed and released into the atmosphere as CO2, (2) primary productivity, which determines how large and for how long plants can grow, and thus how much carbon they store in their leaves and stems, and (3) flammability, which influences how much of the carbon currently stored in plant material and soil is burned and released into the atmosphere during a fire. I will link these trait-function relationships to two databases I have compiled; one contains nearly 100,000 measurements of plant traits, and the other contains more than 30,000 records of plant species composition surveyed over nearly forty years at 260 locations across the Arctic. Identifying measurable relationships between plant traits and ecosystem processes will allow us to understand how warming has influenced and will influence carbon cycling so we can better predict future changes to Earth’s climate.