"Our finding that nutrient availability exerts a stronger control on NEP (net ecosystem production) than on carbon input (GPP) conflicts with assumptions of nearly all global coupled carbon cycle–climate models, which assume that carbon inputs through photosynthesis drive biomass production and carbon sequestration. An improved global understanding of nutrient availability would therefore greatly improve carbon cycle modelling and should become a critical focus for future research." (end of abstract)
"M. Fernández-Martínez, S. Vicca, I. A. Janssens, J. Sardans, S. Luyssaert, M. Campioli, F. S. Chapin III, P. Ciais, Y. Malhi, M. Obersteiner, D. Papale, S. L. Piao, M. Reichstein, F. Rodà &; J. Peñuelas"
Deserts are previously unrecognized sinks, per above study:
4/6/14, "Can Deserts Stop Global Warming? No, but They Help, Study Says," nbcnews.com, by John Roach
for atmospheric carbon dioxide, Evans and colleagues write in a paper published Sunday in the journal Nature Climate Change.
Analysis of the data indicates that desert ecosystems may increase their carbon uptake in the future to account for 15 to 28 percent of the carbon currently being absorbed by land surfaces. Overall, according to the paper, rising carbon dioxide levels may increase the uptake by arid land enough to account for 4 to 8 percent of current emissions.
The team found that most of the carbon was being taken up by soil microbes that surround the roots of plants. In contrast, forest ecosystems tend to store carbon in the plants themselves."...