Soil carbon stocks and land use change: a meta analysis

Abstract

The effects of land use change on soil carbon stocks are of concern in the context of international policy agendas on greenhouse gas emissions mitigation. This paper reviews the literature for the influence of land use changes on soil C stocks and reports the results of a meta analysis of these data from 74 publications. The meta analysis indicates that soil C stocks decline after land use changes from pasture to plantation (−10%), native forest to plantation (−13%), native forest to crop (−42%), and pasture to crop (−59%). Soil C stocks increase after land use changes from native forest to pasture (+ 8%), crop to pasture (+ 19%), crop to plantation (+ 18%), and crop to secondary forest (+ 53%). Wherever one of the land use changes decreased soil C, the reverse process usually increased soil carbon and vice versa. As the quantity of available data is not large and the methodologies used are diverse, the conclusions drawn must be regarded as working hypotheses from which to design future targeted investigations that broaden the database. Within some land use changes there were, however, sufficient examples to explore the role of other factors contributing to the above conclusions. One outcome of the meta analysis, especially worthy of further investigation in the context of carbon sink strategies for greenhouse gas mitigation, is that broadleaf tree plantations placed onto prior native forest or pastures did not affect soil C stocks whereas pine plantations reduced soil C stocks by 12–15%.

Emerging land use practices rapidly increase soil organic matter

“…The transition from crop to pasture systems results in an average 19% increase in soil C stocks 26 . In our intensively grazed systems, we report an B75% increase in C stocks within 6 years of conversion.…”

An LCA researcher's wish list – data and emission models needed to improve LCA studies of animal production

“…CO 2 is emitted) after LUC from pasture to forest plantation (210%), native forest to forest plantation (213%), native forest to crop (242%) and pasture to crop (259%). C stocks instead increase through soil C sequestration in conjunction with LUC when converting from native forest to pasture (18%), crop to pasture (119%), crop to forest plantation (118%) and crop to secondary forest (153%) (Guo and Gifford, 2002). A reasonable summary is that when ecosystems based on perennial vegetation such as pasture and forests are converted into annual crops, this leads to loss of soil organic carbon (SOC) and thus CO 2 emissions.…”

Agricultural land abandonment in Mediterranean environment provides ecosystem services via soil carbon sequestration

“…Among climate factors, precipitation is most frequently considered as one of the principal factors affecting SOC changes after land use change (Alberti et al, 2011;Guo and Gifford, 2002). Precipitation impacts the net primary production (NPP) and consequently the inputs of organic matter to the soil.…”