Woody Plants Invading Grasslands
Cable, J.M., Ogle, K., Tyler, A.P., Pavao-Zuckerman, M.A. and Huxman, T.E. 2009. Woody plant encroachment impacts on soil carbon and microbial processes: results from a hierarchial Bayesian analysis of soil incubation data. Plant and Soil 320: 153-167.
The five researchers discovered that as the invading shrubs grow larger, "the soil beneath their canopies changes whereby all of the following tend to increase: soil carbon stocks, microbial biomass, substrate-use efficiency, and soil respiration." More specifically they report that "total organic carbon under mesquite (big and medium shrubs) was 1.8 and 1.5 times greater than total carbon under bare and grass microsites, respectively," that "microbial biomass was 1.9 and 2.3 times greater under mesquite (big and medium shrubs) compared to grass and bare microsites, respectively," and that "microbes associated with big mesquite had approximately threefold greater carbon substrate-use efficiency than the other three microsites."
Given such findings, it can likely be concluded that as the air's CO2 content continues to rise, promoting the spread of woody plants into semi-arid grasslands around the globe, ever more carbon will likely be captured and stored, both above- and below-ground, which phenomenon tends to slow the rate-of-rise of the atmosphere's CO2 concentration and reduce the ultimate degree of warmth that might otherwise be attained by the planet.