Details

Autor(en) / Beteiligte

• Viglizzo, E.F.
• Ricard, M.F.
• Taboada, M.A.
• Vázquez-Amábile, G.

Titel

Reassessing the role of grazing lands in carbon-balance estimations: Meta-analysis and review

Ist Teil von

• The Science of the total environment, 2019-04, Vol.661, p.531-542

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Assuming a steady state between carbon (C) gains and losses, greenhouse gases (GHG) inventories that follow a widely used simplified procedure (IPCC Tier 1) tend to underestimate the capacity of soils in grazing-land to sequester C. In this study we compared the C balance reported by (i) national inventories that followed the simplified method (Tier 1) of IPCC (1996/2006), with (ii) an alternative estimation derived from the meta-analysis of science-based, peer-reviewed data. We used the global databases (i) EDGAR 4.2 to get data on GHG emissions due to land conversion and livestock/crop production, and (ii) HYDE 3.1 to obtain historical series on land-use/land cover (LULC). In terms of sequestration, our study was focused on C storage as soil organic carbon (SOC) in rural lands of four countries (Argentina, Brazil, Paraguay and Uruguay) within the so-called MERCOSUR region. Supported by a large body of scientific evidence, we hypothesized that C gains and losses in grazing lands are not in balance and that C gains tend to be higher than C losses at low livestock densities. We applied a two-way procedure to test our hypothesis: i) a theoretical one based on the annual conversion of belowground biomass into SOC; and ii) an empirical one supported by peer-reviewed data on SOC sequestration. Average figures from both methods were combined with LULC data to reassess the net C balance in the study countries. Our results show that grazing lands generate C surpluses that could not only offset rural emissions, but could also partially or totally offset the emissions of non-rural sectors. The potential of grazing lands to sequester and store soil C should be reconsidered in order to improve assessments in future GHG inventory reports. [Display omitted] •Carbon sequestration in grasslands is reanalyzed due to inventory carbon miscounting.•Atmosphere-biosphere intersecting factors were studied to reassess carbon balance.•Theoretical and empirical data on carbon sequestration in grasslands were compared.•Carbon gains outweigh carbon losses in grasslands under extensive grazing conditions.•Reassessment of carbon sequestered in grassland soils is needed in inventory reports.