Mapping Carbon Dioxide Emissions from Soil Respiration

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Until recently, there have been no clear assessment of how much  CO2  and the role that soils contribute in emissions relative to other greenhouse gases. Now a global scale map using statistical models and satellite imagery, along with other work by scientists, is beginning to indicate how much land use and soil change can affect our planet’s climate.

In a recent study, a series of machine learning models using multiple nonlinear regression (MNLR), random forest regression (RFR), support vector regression (SVR), and artificial neural network (ANN) were assessed for determining Rs datasets and their measures.

These models were used to create as accurate a picture as possible for soil respiration based on different global biomes evaluated, where the best results from these evaluations were used to make estimates. This allowed a global Rs dataset for 2000-2014 to be created. A global map measuring 1 x 1 km for each square was then created using composite satellite imagery. From that, over the period 2000-2014, maps of Rs are created for each square kilometer on our planet.  

Map of the global distribution of mean annual soil respiration (Rs) between 2000 and 2014. 

 

Overall, regions with high Rs are mainly in the tropics, including the Amazon Basin, Central Africa, and Southeast Asia, while low Rs are widely distributed in the Northern Hemisphere and mainly high-latitude areas in the western United States, Canada, Central Asia, parts of northern Mongolia, northeast China, Argentina, and Australia. Over time, Rs can be seen to increase in the northern latitudes at a more rapid pace, despite being generally lower, with increases approaching 8.5%.

From the results, it is clear that land-cover change was a major contributor to the changes in Rs in temperate (58%) and northerly boreal regions (55%).

 

The Arctic permafrost is becoming a winter source of carbon emissions

 

Climate change itself is a driver of  Rs change, as it affects plant respiration and plant growth. This is most pronounced at a general level at a global scale and in tropical regions, with impact of these factors ranging between 56% and 66% respectively.

It is evident that land use change was a greater factor for Rs change in boreal and temperate regions than in tropical regions.

Central United States, western Europe, northeast China, Kazakhstan, Argentina, east Brazil, east Africa, south Africa, and western Australia all showed decreasing  Rs, which is attributed with drought conditions that have diminished respiration rates.

source:

https://www.gislounge.com/mapping-carbon-dioxide-emissions-from-soil-respiration/