Consequences of warming-driven vegetation change for Arctic carbon cycling and feedbacks to the global climate system

Introduction

ArcticEDGE will identify the consequences of warming-driven vegetation change for the functioning of Arctic ecosystems, particularly the cycling of carbon, and the impact on the global climate. The Arctic is the fastest-warming region on Earth, and Arctic soils contain more than double the amount of carbon currently in the atmosphere.

Impact of Vegetation Changes

Changes in the vegetation can influence whether this carbon is released into the atmosphere, thus contributing to additional climate warming, or stored in soils and plant biomass. Until now, we have lacked the ability to scale up from site-specific, local-scale studies to generalizable vegetation-function relationships relevant for the entire Arctic.

Project Objectives

ArcticEDGE will:

1. Quantify the relationships between widely-measured plant functional and phenological traits and three key ecosystem processes related to global carbon cycling: litter decomposition, primary production, and fire dynamics, 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 turnover in species identity, shifts in abundance, phenotypic plasticity, and genetic differentiation to trait variability and change over time.
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 and precipitation at hundreds of locations across the Arctic.
4. Produce quantifiable outputs that will feed directly into Dynamic Global Vegetation and Earth System models to determine the consequences of Arctic vegetation change for the global climate.

Conclusion

The knowledge generated by ArcticEDGE will contribute both to our theoretical understanding of how plants influence and are influenced by their environment as well as inform urgent efforts to project future changes in the global climate with greater precision.