Latest climate complaint: Arctic plants are getting “too tall”

Plants in the Arctic are growing taller because of climate change, according to research from a global scientific collaboration.

While the region is usually thought of as a vast, desolate landscape of ice, it is in fact home to hundreds of species of low-lying shrubs, grasses and other plants that play a critical role in carbon cycling and energy balance.

Now, a team of experts led by the University of Edinburgh has discovered that the effects of climate change are behind an increase in plant height across the tundra over the past 30 years.

Species spread

As well as the Arctic’s native plants growing in stature, in the southern reaches of the Arctic taller species of plants are spreading across the tundra.

Vernal sweetgrass, which is common in lowland Europe, has now moved in to sites in Iceland and Sweden.

Researchers at the University of Edinburgh and the Senckenberg Biodiversity and Climate Research Centre (BiK-F) in Frankfurt led the international team of 130 scientists in the project, funded by NERC.

More than 60,000 data observations from hundreds of sites across the Arctic and alpine tundra were analysed to produce the findings, which were published in Nature.

Fast-changing

Rapid climate warming in the Arctic and alpine regions is driving changes in the structure and composition of plant communities.

This has important consequences for how this vast and sensitive ecosystem functions.

Arctic regions have long been a focus for climate change research, as the permafrost lying under the northern latitudes contains 30 to 50 percent of the world’s soil carbon.

Taller plants trap more snow, which insulates the underlying soil and prevents it from freezing as quickly in winter.

An increase in taller plants could speed up the thawing of this frozen carbon bank, and lead to an increase in the release of greenhouse gases.

“We found that the increase in height didn’t happen in just a few sites, it was nearly everywhere across the tundra. If taller plants continue to increase at the current rate, the plant community height could increase by 20 to 60 percent by the end of the century.”

Anne BjorkmanClimate Research Centre (BiK-F), Frankfurt

 

Quantifying the link between environment and plant traits is critical to understanding the consequences of climate change, but such research has rarely extended into the Northern hemisphere, home to the planet’s coldest tundra ecosystems. This is the first time that a biome-scale study has been carried out to get to the root of the critical role that plants play in this rapidly warming part of the planet.

Isla Myers-SmithSchool of Geosciences

The team now has a comprehensive data set on Arctic tundra plants, collected from sites in Alaska, Canada, Iceland, Scandinavia and Russia.

Alpine sites in the European Alps and Colorado Rockies were also included in the study.

The team assessed relationships between temperature, soil moisture and key traits that represent plants’ form and function.

Plant height and leaf area were analysed and tracked, along with specific leaf area, leaf nitrogen content and leaf dry matter content, as well as woodiness and evergreenness.

Surprisingly, only height was found to increase strongly over time.

Plant traits were strongly influenced by moisture levels in addition to temperature.

While most climate change models and research have focused on increasing temperatures, our research has shown that soil moisture can play a much greater role in changing plant traits than we previously thought. We need to understand more about soil moisture in the Arctic. Precipitation is likely to increase in the region, but that’s just one factor that affects soil moisture levels.

Isla Myers-SmithSchool of Geosciences

This research is a vital step in improving our understanding of how Arctic and alpine vegetation is responding to climate change. Shrub growth and expansion could have a profound impact not only on the Arctic ecosystem, but also further afield if it results in an increase in the release of greenhouse gases.”

Helen BeadmanHead of Polar, Climate and Weather, Natural Environment Research Council

via Watts Up With That?

https://ift.tt/2NHleo9

September 27, 2018 at 11:23AM

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: