TY - JOUR

T1 - Response of soil organic carbon to land-use change in central Brazil: a large-scale comparison of Ferralsols and Acrisols

AU - Strey, S.

AU - Boy, J.

AU - Strey, R.

AU - Weber, O.

AU - Guggenberger, G.

N1 - Funding Information: This study was carried out in the framework of the integrated project CarBioCial funded by the German Ministry of Education and Research (BMBF) under the grant number 01LL0902F. We express our gratitude to all involved stakeholders and farmers for their professional support and cooperation to realize our studies, and we highly appreciate the trustful partnership of UFTM. Furthermore, we sincerely would like to thank Silke Bokeloh for excellent laboratory work, Steffen Söffker for important support in the field, and all our colleges from CarBioCial for effective interdisciplinary cooperation and stimulating discussions, and particularly Stefan Hohnwald and Michael Klinger for project coordination. Finally we want to thank the two anonymous reviewers and Robert D. McCulloch who helped us to further improve this study.

PY - 2016/11

Y1 - 2016/11

N2 - Background and aims: The southeastern part of the Amazon region is one of the largest agricultural frontiers in the world, leading to extensive land-use change. This paper provides evidence for the impacts of land-use change on soil organic carbon (OC) stocks along a large scale for Ferralsols and Acrisols including subsoil. Methods: We took soil samples to 100 cm depth for native vegetation, pasture and crop-field along a 1000 km agricultural transect in central Brazil to determine OC stocks and, by using a stable isotope approach, losses of forest-derived OC. Results: At the scale of individual plots, soil OC stocks indicate a highly heterogeneous response to land-use change (e.g. in Ferralsols in 0–30 cm from −45 % to +57 % Mg OC ha−1 after conversion to pasture), but relatively minor responses when considering the complete transect (i.e. no significant OC changes for similar land-use type). Acrisols evidenced a slower decline of forest-derived OC and simultaneously a faster accumulation of pasture-derived OC than Ferralsols. Surprisingly, the impact of land-use change was more pronounced in the subsoil. Conclusion: Our results emphasize the role of subsoils on carbon cycling which has been previously underestimated, but may also raise doubts whether OC stocks in soil is an appropriate parameter to assess the impacts of land-use conversion on climate change.

AB - Background and aims: The southeastern part of the Amazon region is one of the largest agricultural frontiers in the world, leading to extensive land-use change. This paper provides evidence for the impacts of land-use change on soil organic carbon (OC) stocks along a large scale for Ferralsols and Acrisols including subsoil. Methods: We took soil samples to 100 cm depth for native vegetation, pasture and crop-field along a 1000 km agricultural transect in central Brazil to determine OC stocks and, by using a stable isotope approach, losses of forest-derived OC. Results: At the scale of individual plots, soil OC stocks indicate a highly heterogeneous response to land-use change (e.g. in Ferralsols in 0–30 cm from −45 % to +57 % Mg OC ha−1 after conversion to pasture), but relatively minor responses when considering the complete transect (i.e. no significant OC changes for similar land-use type). Acrisols evidenced a slower decline of forest-derived OC and simultaneously a faster accumulation of pasture-derived OC than Ferralsols. Surprisingly, the impact of land-use change was more pronounced in the subsoil. Conclusion: Our results emphasize the role of subsoils on carbon cycling which has been previously underestimated, but may also raise doubts whether OC stocks in soil is an appropriate parameter to assess the impacts of land-use conversion on climate change.

KW - Amazon

KW - Land-use change

KW - Large-scale

KW - Soil organic carbon

KW - Tropical soils

UR - http://www.scopus.com/inward/record.url?scp=84973136616&partnerID=8YFLogxK

U2 - 10.1007/s11104-016-2901-6

DO - 10.1007/s11104-016-2901-6

M3 - Article

AN - SCOPUS:84973136616

VL - 408

SP - 327

EP - 342

JO - Plant and soil

JF - Plant and soil

SN - 0032-079X

IS - 1-2

ER -