Are grassland soils of the pampas sequestering carbon?

A belief that grassland soils act as carbon sinks and mitigate greenhouse gas emissions generated by livestock production is common among some farming organizations. A recent theoretical analysis proposed that grazing lands in South America sequester carbon as soil organic matter but this result is controversial. Here, we search for empirical evidence of changes in the carbon stock in the grassland soils of the Pampean region of Argentina.

Soil carbon and belowground carbon balance of a short-rotation coppice: assessments from three different approaches.

Uncertainty in soil carbon (C) fluxes across different land-use transitions is an issue that needs to be addressed for the further deployment of perennial bioenergy crops. A large-scale short-rotation coppice (SRC) site with poplar () and willow () was established to examine the land-use transitions of arable and pasture to bioenergy. Soil C pools, output fluxes of soil CO , CH , dissolved organic carbon (DOC) and volatile organic compounds, as well as input fluxes from litter fall and from roots, were measured over a 4-year period, along with environmental parameters.

Fine root biomass and turnover of two fast-growing poplar genotypes in a short-rotation coppice culture.

Background And Aims: The quantification of root dynamics remains a major challenge in ecological research because root sampling is laborious and prone to error due to unavoidable disturbance of the delicate soil-root interface. The objective of the present study was to quantify the distribution of the biomass and turnover of roots of poplars () and associated understory vegetation during the second growing season of a high-density short rotation coppice culture.

Methods: Roots were manually picked from soil samples collected with a soil core from narrow (75 cm apart) and wide rows (150 cm apart) of the double-row planting system from two genetically contrasting poplar genotypes.