As Ecosystems Heat Up, Tundra Changes Speed Up
Rapid warming in Arctic and alpine regions is driving changes in tundra plant communities, with unknown consequences for the function of these ecosystems. A researcher at the U.S. Department of Energy’s Pacific Northwest National Laboratory contributed to an international study that combined more than 56,000 observations over nearly three decades to examine how the functional traits of tundra plants change over time and space. Results suggest that plant height and closely related tundra ecosystem functions (e.g., carbon uptake) will show the most rapid changes with near-term warming, which is rapidly happening at high latitudes.
The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching due to global-scale vegetation-climate feedbacks. This study provides an understanding of how environmental factors shape biotic communities at the coldest extremes of the planet. The findings will enable improved model projections of tundra changes and related Earth system feedbacks with warming temperatures.
Because plant functional traits are directly related to vital ecosystem processes such as plant growth and decomposition, understanding trait-environment relationships is critical to predicting high-latitude climate feedbacks. Researchers explored the biome-wide relationship between temperature, soil moisture, and key plant functional traits through analysis of trait observations and plant community vegetation surveys at 117 Arctic and alpine tundra sites around the Northern Hemisphere. Over nearly three decades (1989−2015), community plant height increased with warming across all sites, but other traits lagged far behind rates of change predicted from spatial temperature-trait relationships. The findings highlight the challenge of using space-for-time substitution to predict the effects of future warming on tundra composition and function.