Tundra soil carbon is vulnerable to rapid microbial decomposition under climate warming

Published by Christina Schaedel on

Microbial decomposition of soil carbon in high-latitude tundra underlain with permafrost is one of the most important, but poorly understood, potential positive feedbacks of greenhouse gas emissions from terrestrial ecosystems into the atmosphere in a warmer world1, 2, 3, 4. Using integrated metagenomic technologies, we showed that the microbial functional community structure in the active layer of tundra soil was significantly altered after only 1.5 years of warming, a rapid response demonstrating the high sensitivity of this ecosystem to warming. The abundances of microbial functional genes involved in both aerobic and anaerobic carbon decomposition were also markedly increased by this short-term warming. Consistent with this, ecosystem respiration (Reco) increased up to 38%. In addition, warming enhanced genes involved in nutrient cycling, which very likely contributed to an observed increase (30%) in gross primary productivity (GPP). However, the GPP increase did not offset the extra Reco, resulting in significantly more net carbon loss in warmed plots compared with control plots. Altogether, our results demonstrate the vulnerability of active-layer soil carbon in this permafrost-based tundra ecosystem to climate warming and the importance of microbial communities in mediating such vulnerability.

Categories:

Related Posts

A CIRCUIT SHOWS HOW CLIMATE WARMING MAY ALTER DIFFERENT ECOLOGICAL LEGACIES IN THE ARCTIC BOREAL FOREST, WHICH THEN FEEDBACK INTO CLIMATE WARMING AND CHANGES TO LANDSCAPE PROCESSES.

NAU-led research team receives $9.6M to study how Alaska’s forests change, adapt to warmer future

Ecological memory stored in a landscape can help an ecosystem recover from disturbances like fire and outbreaks of disease. But what happens when climate warming disrupts that process? How long before ecological memories stored in Read more…

A SCATTERPLOT DEPICTS HOW MUCH CARBON OR OXYGEN ISOTOPE DIFFERENT SOIL BACTERIA TOOK INTO THEIR DNA (A PROXY FOR GROWTH) DURING A 7-DAY EXPERIMENT. SMALL POINTS REPRESENT THE GROWTH OF INDIVIDUAL BACTERIAL STRAINS LINKED BY LINES TO THE AVERAGE GROWTH OF THEIR CLOSEST IDENTIFIED GENUS. COLORS WERE ASSIGNED BY A CLUSTERING ALGORITHM TO GROUP GENERA INTO FAST-GROWING OR SLOW-GROWING LIFESTYLES.

Lifestyles of the fast and slow (bacteria): In the wild, most live in the slow lane

A study led by Northern Arizona University offers new evidence that a common framework to sort bacteria into two lifestyles doesn’t easily apply to bacteria living in wild soil. The findings, published in The ISME Journal, show Read more…

A trio of illustrated panels depicts the soil microbial communities in three treatments of a long-term warming experiment north of Flagstaff, Arizona. The panels are labeled in gray text, left to right: control, short-term warming, long-term warming. The control treatment, far left, depicts bacteria, protists, and other microorganisms identified by sequencing the soil’s metagenome in yellow, orange, green, and blue, along with chains of available nutrients. Soil depicted in the center panel, which has undergone short-term warming, shows an increased abundance and diversity of microbes, some of which are growing, incorporating nutrients, and respiring carbon dioxide. The soil that has undergone long-term warming, imagined in the panel on the right, shows fewer microbial species and competitive relationships that are developing for control of the scarcer nutrients.

Does a warmer future favor microbial friend or foe? Ecoss researchers win $3.4M to study interactions in changing soil

In 2002, the Odyssey probe discovered evidence of past ice on Mars. The U.S. Congress authorized the Iraq War resolution. The Anaheim Angels won the World Series. And in a meadow 15 miles north of Read more…