Agroforestry Systems

, Volume 31, Issue 2, pp 99–116 | Cite as

Agroforestry systems: sources of sinks of greenhouse gases?

  • R. K. Dixon


The prominent role of forestry and agroforestry systems in the flux and long-term storage of carbon (C) in the terrestrial biosphere has increased global interest in these land-use options to stabilize greenhouse gas (GHG) emissions. Preliminary assessments suggest that some agroforestry systems (e.g., agrosilvicultural) can be CO2 sinks and temporarily store C, while other systems (e.g., ruminant-based silvopastoral systems) are probably sources of GHG (e.g., CH4).

Agroforestry systems can be significant sources of GHG emissions, especially at low latitudes. Practices such as tillage, burning, manuring, chemical fertilization, and frequent disturbance can lead to emission of CO2, CH4, and N2O from soils and vegetation to the atmosphere. Establishment and management of agroforestry systems incompatible with prevailing edaphic and climatic conditions can accelerate soil GHG emissions. Non-sustainable agroforestry systems are quickly degraded, and woody and herbaceous crops can become significant GHG sources. Silvopastoral systems can result in soil compaction and erosion with significant loss of labile C and N compounds to the atmosphere. Ruminant-based silvopastoral systems and rice paddy agrisilvicultural systems are well documented sources of CH4 which significantly contribute to the global CH4 budget.

Early assessments of national and global terrestrial CO2 sinks reveal two primary beneficial attributes of agroforestry systems: 1) direct near-term C storage (decades to centuries) in trees and soils, and, 2) potential to offset immediate GHG emissions associated with deforestation and subsequent shifting agriculture. Within the tropical latitudes, it is estimated that one ha of sustainable agroforestry can provide goods and services which potentially offset 5–20 ha of deforestation. At a global scale, agroforestry systems could potentially be established on 585–1275×106 ha of technically suitable land, and these systems could store 12–228 (median 95) Mg C ha−1 under current climate and edaphic conditions.

Key words

global change carbon dioxide methane environment climate 


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  1. Andrasko K, Heaton K and Winnett S (1991) Evaluating the costs and efficiency of options to manage global forests: a cost curve approach. In: Howlett D and Sargent C (eds) Proceedings of Technical Workshop to Explore Options for Global Forestry Management IIED, pp 216–233, London, UKGoogle Scholar
  2. Apps MJ, Kurz WA, Luxmoore RJ Nilsson LL, Sedjo RA, Schmidt R, Simpson LG and Vinson TS (1993) Boreal forests and tundra. Water, Air and Soil Pollution 70: 39–54CrossRefGoogle Scholar
  3. Barnwell TO, Jackson RB IV, Elliott ET, Burke IC, Cole CV, Paustian K, Paul EA, Donigian AS, Patwardhan AS, Rowell A and Weinrich K (1992) An approach to assessment of management impacts on agricultural carbon. Water, Air and Soil Pollution 64: 423–435CrossRefGoogle Scholar
  4. Barrett-Lennard EG, Malcom CV, Stern WR and Wilkins SM (eds) (1986) Forage and Fuel Production from Salt Affected Wasteland. Elsevier Science Publishing, New York, 459 ppGoogle Scholar
  5. Birdsey RA, Plantiga AJ and Heath LS (1993) Past and prospective carbon storage in United States forests. Forest Ecology and Management 58: 33–40CrossRefGoogle Scholar
  6. Boonkird SA, Fernandes ECM and Nair PKR (1984) Forest villages: an agroforestry approach to rehabilitating forest land degraded by shifting cultivation in Thailand. Agroforestry Systems 2: 87–102Google Scholar
  7. Bouwman AF (ed) (1989) Soils and the Greenhouse Effect. Wiley, New YorkGoogle Scholar
  8. Brown S, Hall CAS, Knabe W, Raich J, Trexler MC and Woomer P (1993) Tropical forests: their past, present and potential future role in the terrestrial carbon budget. Water, Air and Soil Pollution 70: 71–94CrossRefGoogle Scholar
  9. Burley J and Stewart J (1985) Increasing Productivity of Multipurpose Trees. International Union of Forest Research Organizations, Vienna, Austria, 560 ppGoogle Scholar
  10. Cole CV, Flach K, Lee J, Sauerbeck D and Stewart B (1993) Agricultural sources and sinks of carbon. Water, Air and Soil Pollution 70: 111–122Google Scholar
  11. Cramer WP and Solomon AM (1993) Climatic classification and future global redistribution of agricultural land. Climate Research 3: 97–110Google Scholar
  12. Dixon RK and Turner DP (1991) The global carbon cycle and climate change: responses and feedbacks from belowground systems. Environmental Pollution 73: 245–262CrossRefPubMedGoogle Scholar
  13. Dixon RK, Andrasko KJ, Sussman FA, Lavinson MA, Trexler MC and Vinson TS (1993a) Forest sector carbon offset programs: near-term opportunities to reduce greenhouse gas emissions to the atmosphere. Water, Air and Soil Pollution 70: 561–577CrossRefGoogle Scholar
  14. Dixon RK, Winjum JK and Schroeder PE (1993b) Conservation and sequestration of carbon: the potential of forest and agroforest management practices Global Environmental Change. 2: 159–173Google Scholar
  15. Dixon RK, Brown S, Houghton RA, Solomon AM, Trexler MC and Wisniewski J (1994a) Carbon pools and flux of global forest ecosystems. Science 263: 185–190Google Scholar
  16. Dixon RK, Winjum JK, Andrasko KJ, Lee JJ and Schroeder PE (1994b) Integrated systems: assessment of promising agroforest and alternative land-use practices to enhance carbon conservation and sequestration. Climatic Change 30: 1–23Google Scholar
  17. Garrett HE (ed) (1991) Proceedings of Second Conference on Agroforestry in North America. University of Missouri, Columbia, MO, 403 ppGoogle Scholar
  18. Gaston GG, Kolchugina TP and Vinson TS (1993) Potential effect of no-till management on carbon in the agricultural soils of the former Soviet Union. Agriculture, Ecosystems and Environment 45: 295–309CrossRefGoogle Scholar
  19. Grainger A (1988) Estimating areas of degraded tropical lands requiring replenishment of forest cover. International Tree Crop Journal 5: 31–61Google Scholar
  20. Gregerson H, Draper S and Elz D (eds) (1989) People and Trees: The Role of Social Forestry in Sustainable Development. EDI Seminar Series. The World Bank, Washington, DC, 273 ppGoogle Scholar
  21. Heath LS, Kauppi PE, Burschel P, Gregor HD, Guderion R, Kohlmaier GH, Lorenz S, Overdieck D, Scholz F, Thoasius H and Weber M (1993) Contribution of temperate forests to the world.s carbon budget. Water, Air and Soil Pollution 70: 55–70Google Scholar
  22. Hellden U (1992) Desertification-time for an assessment? Ambio 20: 372–383Google Scholar
  23. Hogan KP and Leng RA (1992) Methane emissions form ruminants in semi-arid regions. In: Boag S (ed) Proceedings of Workshop: Assessing Technologies and Management systems of Agriculture and Forestry in Relation to Climate Change, pp 102–104. Australian Government Publishing Service, Canberra, AustraliaGoogle Scholar
  24. Houghton RA, Unruh JD and Lefebvre PA (1993) Current land use in the tropics and its potential for sequestering carbon. Global Biogeochemical Cycles 7: 305–320Google Scholar
  25. Howden SM, McKeon GM, Scanlon JC, Carger JO, White DH and Galbally IE (1992) Managing pastures in northern Australia. to minimize greenhouse gas emissions. In: Boag S (ed) Proceedings of Workshop: Assessing Technologies and Management Systems of Agriculture and Forestry in Relation to Climate Change, pp 61–67. Australian Government Publishing Service, Canberra, AustraliaGoogle Scholar
  26. IMF (1990) International Financial Statistics Yearbook. International Monetary Fund, Volume XLIV. Washington, DC, 602 ppGoogle Scholar
  27. Iverson LR, Brown S, Grainger A, Prasad A and Liu D (1993) Carbon sequestration in tropical Asia: an assessment of technically suitable forest lands using geographic information analysis. Climate Research 3: 23–38Google Scholar
  28. Jain RK, Paliwal K, Dixon RK and Gjerstad DH (1989) Improving productivity of multipurpose trees growing on substandard soils in India. Journal of Forestry 87: 38–42Google Scholar
  29. Jenkinson DS and Rayner JH (1977) The turnover of soil organic matter in some of the Rothamsted classical experiments. Soil Science 5: 298–305Google Scholar
  30. Johnson DW (1992) Effects of forest management on soil carbon storage. Water, Air and Soil Pollution 64: 83–100CrossRefGoogle Scholar
  31. Kauppi PE, Mielikainen K and Kuusela K (1992) Biomass and carbon budget of European forests, 1971–1990. Science 256, 70–74Google Scholar
  32. Kern JS and Johnson MG (1993) Conservation tillage impacts on national soil and atmospheric carbon levels. Soil Science Society of America Journal 57: 200–210Google Scholar
  33. King GA (1993) Conceptual approaches for incorporating climate change into the development of forest management options for sequestering carbon. Climate Research 3: 61–78Google Scholar
  34. Krankina ON and Dixon RK (1992) Forest management in Russia: challenges and opportunities in the era of perestroika. Journal of Forestry 90: 29–34Google Scholar
  35. Krankina ON and Dixon RK (1994) Forest management options to conserve and sequester terrestrial carbon in Russia. World Resource Review 6: 88–101Google Scholar
  36. Lal R (1989) Agroforestry systems and soil surface management of a tropical Alfisol. III. Soil chemical properties. Agroforestry Systems 8: 113–132Google Scholar
  37. Lugo AE, Sanchez MJ and Brown S (1986) Land use and organic carbon content of some subtropical soils. Plant and Soil 96: 185–196Google Scholar
  38. MacDicken KG and Vergara NT (eds) (1990) Agroforestry: Classification and Management. Wiley, New York, 382 ppGoogle Scholar
  39. Manabe S and Wetherald RT (1987) Large-scale changes in soil wetness induced by an increase in carbon dioxide. Journal of Atmospheric Science 44: 1211–1235CrossRefGoogle Scholar
  40. Mitchell JFB (1989) The greenhouse effect and climate change. Review of Geophysics 27: 115–139Google Scholar
  41. Nair PKR (ed) (1989) Agroforestry Systems in the Tropics. Kluwer Academic Publishers, Dordrecht, The Netherlands, 665 ppGoogle Scholar
  42. Nair PKR (1993) An Introduction to Agroforestry. Kluwer Academic Publishers, Dordrecht, The Netherlands, 499 ppGoogle Scholar
  43. Nair PKR (1994) Agroforestry. Encyclopedia of Agricultural Sciences, Vol 1, pp 5–23. Academic Press, New YorkGoogle Scholar
  44. National Academy of Sciences (NAS) (1991) Policy Implications of Greenhouse Warming. US National Academy Press, Washington DC, 127 ppGoogle Scholar
  45. Ojima DS, Dirks BOM, Glenn EP, Owensby CE and Scurlock JO (1993) Assessment of C budget for grasslands and drylands of the world. Water, Air and Soil Pollution 70: 95–110Google Scholar
  46. Row C (1978) Economics of track size in timber growing. Journal of Forestry 76: 576–582Google Scholar
  47. Rubin ES, Cooper RM, Frosch RA, Lee TH, Marland G, Rosenfeld AH and Stine DD (1992) Realistic mitigation options for global warming. Science 257: 148–266Google Scholar
  48. Sampson RN and Hair D (eds) (1992) Forests and Global Change. Vol I. Opportunities for Increasing Forest Cover. American Forests, Washington DC, 285 ppGoogle Scholar
  49. Sampson RN, Wright LL, Winjum JK, Kinsman JD, Benneman J, Kürsten E and Scurlock JMO (1993) Biomass management and energy. Water, Air and Soil Pollution 70: 139–159Google Scholar
  50. Sanchez PA and Benites JR (1987) Low-input cropping for acid soils of the humid tropics. Science 238: 1521–1527Google Scholar
  51. Schneider SJ (1989) The greenhouse effect: science and policy. Science 243: 771–781Google Scholar
  52. Schroeder P (1993) Agroforestry systems: integrated land use to store and conserve carbon. Climate Research 3: 53–60Google Scholar
  53. Schroeder PE, Dixon RK and Winjum JK (1993) Forest management and agroforestry to sequester and conserve atmospheric carbon dioxide. Unasylva 44: 52–60Google Scholar
  54. Smith TM, Shugart HH, Bonan GB and Smith JB (1991) Modeling the potential response of vegetation to global climate change. Advances in Ecological Research 22: 93–116Google Scholar
  55. Smith TM, Cramer WP, Dixon RK, Leemans R, Neilson RP and Solomon AM (1993) The global terrestrial carbon cycle. Water, Air and Soil Pollution 70: 19–38Google Scholar
  56. Trexler MC and Haugen CM (1995) Keeping it Green: Evaluating Tropical Forestry Strategies to Slow Global Warming. World Resources Institute, Washington DC, 52 ppGoogle Scholar
  57. Turner DP, Koerper G, Gucinski H, Peterson C and Dixon RK (1993) Monitoring global comparison of forest cover estimates using remote sensing and inventory approaches. Environmental Monitoring and Assessment 26: 295–305CrossRefGoogle Scholar
  58. Unruh JD, Houghton RA and Lefebvre PA (1993) Carbon storage in agroforestry: an estimate for sub-Saharan Africa. Climate Research 3: 39–52Google Scholar
  59. Winjum JK, Dixon RK and Schroeder PE (1992) Estimating the global potential of forest and agroforest management practices to sequester carbon. Air, Water and Soil Pollution 64: 213–228Google Scholar
  60. Winjum JK and Lewis DK (1993) Forest management and the economics of carbon storage: the non-financial component. Climate Research 3: 111–119Google Scholar
  61. Winjum JK, Dixon RK and Schroeder PE (1993a) Forest management and carbon storage: an analysis of 12 key forest nations. Air, Water and Soil Pollution 70: 239–257Google Scholar
  62. Winjum JK, Meganck RA and Dixon RK (1993b) Expanding global forest management: an easy-first proposal. Journal of Forestry 91: 38–42Google Scholar

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • R. K. Dixon
    • 1
  1. 1.US Support for Country Studies to Address Climate ChangeWashingtonUSA

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