Effects of Climate Change and Vegetation Type on Carbon and Nitrogen Accumulation during Incipient Soil Formation
Résumé
Plants play an important role in carbon and nitrogen fluxes in the
environment. Plants remove carbon from the atmosphere through
photosynthesis and deposit a fraction of this carbon into the soil as a
result of root exudation and senescence, contributing to soil formation.
Additionally, plants can facilitate sequestration of CO2 from the
atmosphere in inorganic form during the process of mineral weathering.
With increasing temperatures and levels of CO2 in the atmosphere, it is
unknown what effect these changes will have on plant growth and
weathering of silicate rocks, and by extension on carbon accumulation in
the soils. To identify climate change effects on C and N fluxes, a
controlled study was conducted at Ecotron Ile-de-France utilizing
mesocosms maintained at elevated and ambient CO2 concentration and
temperature with four different vegetation treatments: control, alfalfa,
velvet mesquite, and green sprangletop. Each experiment lasted for 4
months with monthly rainfall events using deionized water. After each
rain, soil solution and drainage were collected and analyzed for major
and trace elements, as well as anions, nitrogen, and organic and
inorganic carbon. CO2 concentrations in the soil air were monitored as
well. At the end of this study, soil samples were collected from each
mesocosm at four different depths and then analyzed for organic carbon,
inorganic carbon, and total nitrogen. Accumulation of organic and
inorganic carbon and nitrogen with clear differences with depth was
observed in all mesocosms. Elevated CO2 in the atmosphere influenced C
accumulation in the soils, while the type of vegetation significantly
affected concentrations of nitrogen and organic carbon in soil and
solution. This indicates that climate change would affect carbon and
nitrogen fluxes in the soils causing feedbacks to the atmospheric CO2.
Auteurs, date et publication :
Auteurs R. Hingley , S. Juarez , K. Dontsova , E. Hunt , J. F. Le Galliard , S. Chollet , A. Cros , M. Llavata , F. Massol , P. Barré , A. Gelabert , D. Daval , P. A. A. Troch , G. Barron-Gafford , J. L. M. Van Haren , R. Ferrière
Date : 2016
Volume : 53