Global Tree Cover and Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets

Agroforestry systems and tree cover on agricultural land make an important contribution to climate change mitigation, but are not systematically accounted for in either global carbon budgets or national carbon accounting. This paper assesses the role of trees on agricultural land and their significance for carbon sequestration at a global level, along with recent change trends. Remote sensing data show that in 2010, 43% of all agricultural land globally had at least 10% tree cover and that this has increased by 2% over the previous ten years. Combining geographically and bioclimatically stratified Intergovernmental Panel on Climate Change (IPCC) Tier 1 default estimates of carbon storage with this tree cover analysis, we estimated 45.3 PgC on agricultural land globally, with trees contributing >75%. Between 2000 and 2010 tree cover increased by 3.7%, resulting in an increase of >2 PgC (or 4.6%) of biomass carbon. On average, globally, biomass carbon increased from 20.4 to 21.4 tC ha−1. Regional and country-level variation in stocks and trends were mapped and tabulated globally, and for all countries. Brazil, Indonesia, China and India had the largest increases in biomass carbon stored on agricultural land, while Argentina, Myanmar, and Sierra Leone had the largest decreases.

[1]  J. Townshend,et al.  Global Percent Tree Cover at a Spatial Resolution of 500 Meters: First Results of the MODIS Vegetation Continuous Fields Algorithm , 2003 .

[2]  R. Lal.  Agricultural activities and the global carbon cycle , 2004, Nutrient Cycling in Agroecosystems.

[3]  P. Nair,et al.  Carbon sequestration studies in agroforestry systems: a reality-check , 2011, Agroforestry Systems.

[4]  Jianchu Xu,et al.  Alder trees enhance crop productivity and soil microbial biomass in tea plantations , 2015 .

[5]  N. H. Ravindranath,et al.  Land Use, Land-Use Change, and Forestry: A Special Report of the Intergovernmental Panel on Climate Change , 2000 .

[6]  D. Soltis,et al.  Large-scale phylogenetic analyses reveal multiple gains of actinorhizal nitrogen-fixing symbioses in angiosperms associated with climate change , 2015, Scientific Reports.

[7]  S. Carpenter,et al.  Solutions for a cultivated planet , 2011, Nature.

[8]  Alain Albrecht,et al.  Carbon sequestration in tropical agroforestry systems , 2003 .

[9]  R. Lal,et al.  Soil Carbon Sequestration Impacts on Global Climate Change and Food Security , 2004, Science.

[10]  F. Dakora,et al.  Contribution of legume nitrogen fixation to sustainable agriculture in Sub-Saharan Africa , 1997 .

[11]  The Role of Agriculture in the UN Climate Talks , 2014 .

[12]  S. Goetz,et al.  Importance of biomass in the global carbon cycle , 2009 .

[13]  M. Noordwijk.  Climate Change: Agricultural Mitigation , 2014 .

[14]  R. B. Jackson,et al.  A Large and Persistent Carbon Sink in the World’s Forests , 2011, Science.

[15]  A. Leguizamón.  Modifying Argentina: GM soy and socio-environmental change , 2014 .

[16]  R. Zomer,et al.  Trees on farm: analysis of global extent and geographical patterns of agroforestry. , 2009 .

[17]  James H. Brown,et al.  Metabolic theory predicts whole-ecosystem properties , 2015, Proceedings of the National Academy of Sciences.

[18]  Stephen Polasky,et al.  Global agriculture and carbon trade-offs , 2014, Proceedings of the National Academy of Sciences.

[19]  A. Belward,et al.  GLC2000: a new approach to global land cover mapping from Earth observation data , 2005 .

[20]  E. Noellemeyer,et al.  Soil Carbon: Science, Management and Policy for Multiple Benefits , 2014 .

[21]  J. Lynch,et al.  The opening of Pandora’s Box: climate change impacts on soil fertility and crop nutrition in developing countries , 2010, Plant and Soil.

[22]  R. Wynne,et al.  Rebuilding the Brazilian rainforest: Agroforestry strategies for secondary forest succession , 2013 .

[23]  Douglas W. Nychka,et al.  A comparison of a GCM response to historical anthropogenic land cover change and model sensitivity to uncertainty in present-day land cover representations , 2005 .

[24]  Thiago Almeida Vieira,et al.  ADOPTION OF AGROFORESTRY SYSTEMS BY SMALLHOLDERS IN BRAZILIAN AMAZON , 2012 .

[25]  Pablo Lapegna.  Global Ethnography and Genetically Modified Crops in Argentina , 2014 .

[26]  Liming Zhou,et al.  Afforestation in China cools local land surface temperature , 2014, Proceedings of the National Academy of Sciences.

[27]  R. Houghton,et al.  Aboveground Forest Biomass and the Global Carbon Balance , 2005 .

[28]  P. Nair,et al.  Chapter five. Carbon sequestration in agroforestry systems. , 2010 .

[29]  S. Carpenter,et al.  Global Consequences of Land Use , 2005, Science.

[30]  E. Luedeling,et al.  Agroforestry solutions to address food security and climate change challenges in Africa , 2014 .

[31]  J. Bruinsma,et al.  World agriculture towards 2030/2050: the 2012 revision , 2012 .

[32]  Yoshiki Yamagata,et al.  Supplementary Methods and Good Practice Guidance Arising from the Kyoto Protocol , 2004 .

[33]  Meine van Noordwijk,et al.  Protected areas within multifunctional landscapes: squeezing out intermediate land use intensities in the tropics? , 2013 .

[34]  Meine van Noordwijk,et al.  Implications of uncertainty and scale in carbon emission estimates on locally appropriate designs to reduce emissions from deforestation and degradation (REDD+) , 2013, Mitigation and Adaptation Strategies for Global Change.

[35]  C. Müller,et al.  Modelling the role of agriculture for the 20th century global terrestrial carbon balance , 2007 .

[36]  Matthew F. McCabe,et al.  Recent reversal in loss of global terrestrial biomass , 2015 .

[37]  Gerardo Reyes Guzmán.  The Future of Food and Farming: Challenges and Choices for Global Sustainability , 2011 .