The tundra is a vast, flat, treeless Arctic region of Europe, Asia, and North America where the subsoil is permanently frozen – or that, at least, used to be the case.
“The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate,” says a new study published in the journal Nature.
The huge study spanned over three decades and involved 180 scientists analyzing 56,048 trait records and 117 vegetation survey sites across the tundra.
The study found that low-lying shrubs, grasses and other plants in the Arctic are getting taller due to rising temperatures. The growth in height and specific leaf area was more marked at wetter than drier sites.
Taller Arctic plants trap more snow around them, preventing the soil from freezing quite so hard. This makes it easier for the permafrost to thaw out in summer months and release carbon into the atmosphere. Up to 50 per cent of the world’s below-ground carbon stocks are contained in permafrost soils.
Also, taller plants by sticking out above the snow, help make the Earth’s surface darker, allowing the tundra ecosystem to trap more heat from the sun.
Plant traits strongly affect carbon cycling and the energy balance of the ecosystem, which can in turn influence regional and global climates. “A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning,” says the study.
One of UN Environment’s objectives in terms of mitigation is to keep track of emerging issues and opportunities in global climate.
“This is an important study which should help to improve projections of changes in tundra ecosystems with climate warming,” says UN Environment climate change expert Niklas Hagelberg.
The Intergovernmental Panel on Climate Change is due to publish an important report today examining the challenges and impacts of keeping temperatures below 1.5°C, and in November, UN Environment will be releasing its latest edition of the Emissions Gap report.
Source : www.unenvironment.org
