Soil bogging caused by climate change adds to the greenhouse effect, says a RUDN University soil sci

September 19, 2020

A soil scientist from RUDN University studied soil samples collected at the Tibetan Plateau and discovered that high soil moisture content (caused by the melting of permafrost and glaciers) leads to further temperature increase. Therefore, the rate of soil bogging should be held back in order to slow down global warming. The results of the study were published in the Soil Biology and Biochemistry journal.

The main reason for global climate change is the growing concentration of carbon dioxide in the atmosphere. Carbon dioxide keeps the heat in and prevents the planet from cooling off, causing the greenhouse effect. Humans are not the only sources of carbon dioxide. Even our soil breathes it out: it contains different compounds that release carbon in the form of CO2. Global warming causes glaciers and permafrost to melt which increases soil moisture content. Until recently, scientists had been unaware whether the growth of soil moisture affects the volumes of emitted carbon dioxide. To find it out, a soil scientist from RUDN University studied soil samples collected at the Tibetan Plateau--a place where temperature grows three times faster than anywhere on the planet.

"Soil drainage advances the mineralization of carbon in the soil and increases the volume of carbon dioxide emissions. However, the growth of soil moisture content should not necessarily lead to the opposite effect. To find out whether it is really so, we studied these processes in wetland and meadow soils that have contrasting biochemical properties," said Yakov Kuzyakov, a PhD in Biology, and the Head of the Center for Mathematical Modeling and Design of Sustainable Ecosystems at RUDN University.

The scientists took samples of meadow and wetland soils and identified what substances in them contained carbon: undecomposed plant waste or decomposed biomass. After that meadow soil was saturated with water up to 70% of liquid content it was able to hold. Wetland soil was left for 95 days at 25 ? to dry out. Then the team measured the carbon content in the samples once again and described changes in respective carbon dioxide emission rates.

After all these manipulations, both samples turned out to emit carbon dioxide more intensively. According to the team, it is explained by the initial carbon content of the samples. In wetland soils, carbon is mainly found in plant waste that has not decomposed yet. On the contrary, in meadow soils, the source of carbon is mainly decomposed biomass in which soil enzymes are more active. Therefore, high moisture slows down carbon mineralization and carbon dioxide emissions in wetland soils, but in meadow soils, it accelerates both processes.

"We confirmed that carbon decomposition in water-filled soil depends on the initial plant and microbial residue content and showed that biochemistry should be taken into consideration when regulating carbon decomposition. Both the reclamation of wetlands and the bogging of meadowlands increase carbon mineralization measured in the form of CO2 emissions," added Yakov Kuzyakov.

The study shows that protecting meadowlands from bogging can help reduce carbon dioxide emissions and slow down global warming. Otherwise, a chain reaction may occur: the greenhouse effect would further promote global warming, which would in turn lead to more meadowland bogging.
-end-


RUDN University

Related Global Warming Articles from Brightsurf:

The ocean has become more stratified with global warming
A new study found that the global ocean has become more layered and resistant to vertical mixing as warming from the surface creates increasing stratification.

Containing methane and its contribution to global warming
Methane is a gas that deserves more attention in the climate debate as it contributes to almost half of human-made global warming in the short-term.

Global warming and extinction risk
How can fossils predict the consequences of climate change? A German research team from Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), the Museum of Natural History Berlin and the Alfred Wegener Institute compared data from fossil and marine organisms living today to predict which groups of animals are most at risk from climate change.

Intensified global monsoon extreme rainfall signals global warming -- A study
A new study reveals significant associations between global warming and the observed intensification of extreme rainfall over the global monsoon region and its several subregions, including the southern part of South Africa, India, North America and the eastern part of the South America.

Global warming's impact on undernourishment
Global warming may increase undernutrition through the effects of heat exposure on people, according to a new study published this week in PLOS Medicine by Yuming Guo of Monash University, Australia, and colleagues.

Global warming will accelerate water cycle over global land monsoon regions
A new study provides a broader understanding on the redistribution of freshwater resources across the globe induced by future changes in the monsoon system.

Comparison of global climatologies confirms warming of the global ocean
A report describes the main features of the recently published World Ocean Experiment-Argo Global Hydrographic Climatology.

Six feet under, a new approach to global warming
A Washington State University researcher has found that one-fourth of the carbon held by soil is bound to minerals as far as six feet below the surface.

Can we limit global warming to 1.5 °C?
Efforts to combat climate change tend to focus on supply-side changes, such as shifting to renewable or cleaner energy.

Global warming: Worrying lessons from the past
56 million years ago, the Earth experienced an exceptional episode of global warming.

Read More: Global Warming News and Global Warming Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.