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Managing genetic variation in tropical trees: linking knowledge with action in agroforestry ecosystems for improved conservation and enhanced livelihoods

Abstract

Tree species in agroforestry ecosystems contribute to the livelihoods of rural communities and play an important role in the conservation of biodiversity. Unless agroforestry landscapes are productive, however, farmers will not maintain or enhance the range and quality of tree species in them, and both income opportunities and biodiversity will be lost. Productivity depends on both tree species diversity and genetic (intra-specific) variation, but research on the latter has until recently not received the recognition it deserves. Worse, when knowledge on tree genetic variation in agroforestry systems has become available, it has not generally been linked in any systematic way with management, indicating a disjunction between research and field-level practice. In this essay, we attempt to bridge this gap by considering three questions: why is genetic diversity important in tree species? What is our current state of knowledge about intra-specific variation in trees in agroforestry systems? And, finally, what practical interventions are possible to support the conservation of this diversity in agricultural landscapes, while enhancing farmers’ livelihoods? A wide genetic base in agroforestry trees is essential to prevent inbreeding depression and allow adaptation to changing environmental conditions and to altering markets for tree products. Recent evidence shows, however, that many species are subject to poor germplasm collection practice, occur at low densities in farmland, and are found in highly aggregated distributions, all of which observations raise concerns about productivity and sustainability. A range of germplasm-access based interventions is necessary to improve current management, including the enhancement of community seed- and seedling-exchange networks, and the development of locally based tree domestication activities. Equally necessary, but more difficult to address, is the development of markets that support genetic diversity in tropical tree species; we discuss approaches by which this may be undertaken.

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References

  1. Acharya KP (2006) Linking trees on farms with biodiversity conservation in subsistence farming systems in Nepal. Biodivers Conserv 15:631–646. doi:10.1007/s10531-005-2091-7

    Article  Google Scholar 

  2. Aitken SN, Yeaman S, Holliday JA, Wang T, Curtis-McLane S (2008) Adaptation, migration or extirpation: climate change outcomes for tree populations. Evol Appl 1:95–111. doi:10.1111/j.1752-4571.2007.00013.x

    Article  Google Scholar 

  3. Akinnifesi FK, Kwesiga F, Mhango J, Chilanga T, Mkonda A, Kadu CAC, Kadzere I, Mithofer D, Saka JDK, Sileshi G, Ramadhani T, Dhliwayo P (2006) Towards the development of miombo fruit trees as commercial tree crops in southern Africa. For Trees Livelihoods 16:103–121

    Google Scholar 

  4. Assogbadjo AE, Kyndt T, Sinsin B, Gheysen G, Van Damme P (2006) Patterns of genetic and morphometric diversity in baobab (Adansonia digitata) populations across different climatic zones of Benin (West Africa). Ann Bot (Lond) 97:819–830. doi:10.1093/aob/mcl043

    Article  CAS  Google Scholar 

  5. Atta-Krah K, Kindt R, Skilton JN, Amaral W (2004) Managing biological and genetic diversity in tropical agroforestry. Agrofor Syst 61:183–194. doi:10.1023/B:AGFO.0000028998.32732.65

    Article  Google Scholar 

  6. Bawa KS, Dayanandan S (1998) Global climate change and tropical forest genetic resources. Clim Change 39:473–485. doi:10.1023/A:1005360223639

    Article  Google Scholar 

  7. Boivin-Chabot S, Margolis HA, Weber JC (2004) Variation in coppice-shoot growth among provenances of Calycophyllum spruceanum Benth. in the Peruvian Amazon Basin. For Ecol Manag 198:249–260. doi:10.1016/j.foreco.2004.04.009

    Article  Google Scholar 

  8. Boshier DH (2000) Mating systems. In: Young A, Boshier D, Boyle T (eds) Forest conservation genetics: principles and practice. CSIRO Publishing/CABI Publishing, Melbourne/Wallingford, pp 63–79

    Google Scholar 

  9. Boshier DH (2004) Agroforestry systems: important components in conserving the genetic viability of native tropical tree species? In: Schroth G, da Fonseca GAB, Harvey CA, Gascon C, Vasconcelos HL, Izac A-MN (eds) Agroforestry and biodiversity conservation in tropical landscapes. Island Press, Washington, pp 290–313

    Google Scholar 

  10. Bouvet J-M, Kelly B, Sanou H, Allal F (2008) Comparison of marker- and pedigree-based methods for estimating heritability in an agroforestry population of Vitellaria paradoxa C.F. Gaertn (shea tree). Genet Resour Crop Evol (in press)

  11. Brodie AW, Labarta-Chávarri RA, Weber JC (1997) Tree germplasm management and use on-farm in the Peruvian Amazon: a case study from the Ucayali region, Peru. Research Report, Overseas Development Institute (ODI), London and the World Agroforestry Centre (ICRAF), Nairobi

  12. Charlesworth D, Charlesworth B (1987) Inbreeding depression and its evolutionary consequences. Annu Rev Ecol Syst 18:237–268. doi:10.1146/annurev.es.18.110187.001321

    Article  Google Scholar 

  13. Cornelius JP, Clement CR, Weber JC, Sotelo-Montes C, van Leeuwen J, Ugarte-Guerra LJ, Ricse-Tembladera A, Arevalo-Lopez L (2006) The trade-off between genetic gain and conservation in a participatory improvement programme: the case of peach palm (Bactris gasipaes Kunth). For Trees Livelihoods 16:17–34

    Google Scholar 

  14. Crutsinger GM, Collins MD, Fordyce JA, Gompert Z, Nice CC, Sanders NJ (2006) Plant genotypic diversity predicts community structure and governs an ecosystem process. Science 313:966–968. doi:10.1126/science.1128326

    PubMed  Article  CAS  Google Scholar 

  15. Dawson I, Were J (1998) Multiplication, that’s the name of the game guidelines for seed production of agroforestry trees. Agrofor Today 10:19–22

    Google Scholar 

  16. Dawson IK, Guarino L, Jaenicke H (2007) Underutilised plant species: impacts of promotion on biodiversity. ICUC Position Paper No. 2. The International Centre for Underutilised Crops, Colombo

  17. Dawson IK, Hedley PE, Guarino L, Jaenicke H (2008a) Does biotechnology have a role in the promotion of underutilised crops? Food Policy (in press)

  18. Dawson IK, Hollingsworth PM, Doyle JJ, Kresovich S, Weber JC, Sotelo-Montes C, Pennington TD, Pennington RT (2008b) Origin and genetic conservation of tropical trees in agroforestry systems: a case study from the Peruvian Amazon. Conserv Genet 9:361–372. doi:10.1007/s10592-007-9348-5

    Article  Google Scholar 

  19. Degrande A, Schreckenberg K, Mbosso C, Anegbeh P, Okafor V, Kanmegne J (2006) Farmers’ fruit tree-growing strategies in the humid forest zone of Cameroon and Nigeria. Agrofor Syst 67:159–175. doi:10.1007/s10457-005-2649-0

    Article  Google Scholar 

  20. Donald PF (2004) Biodiversity impacts of some agricultural commodity production systems. Conserv Biol 18:17–37. doi:10.1111/j.1523-1739.2004.01803.x

    Article  Google Scholar 

  21. Edwards D, Schreckenberg K (1997) Demand from smallholder farmers for multipurpose tree germplasm: implications for policy, research and development. In: Simons AJ, Kindt R, Place F (eds) Policy aspects of tree germplasm demand and supply. Proceedings of an international workshop. The World Agroforestry Centre (ICRAF), Nairobi, pp 9–26

  22. El-Kassaby YA, Cook C (1994) Female reproductive energy and reproductive success in a Douglas-fir seed orchard and its impact on genetic diversity. Silvae Genet 43:243–246

    Google Scholar 

  23. El-Kassaby YA, Fashler AMK, Crown M (1989) Variation in fruitfulness in a Douglas-fir seed orchard and its effect on crop-management decisions. Silvae Genet 38:113–121

    Google Scholar 

  24. FAO (2004) Preliminary review of biotechnology in forestry, including genetic modification. Forest genetic resources working paper FGR/59E. Food and Agriculture Organization of the United Nations, Rome

  25. FAO (2006) Global forest resources assessment 2005. Main report, FAO Forestry Paper 147. Food and Agriculture Organization of the United Nations, Rome

  26. Friis-Hansen E, Sthapit B (eds) (2000) Participatory approaches to the conservation and use of plant genetic resources. Bioversity International (formerly the International Plant Genetic Resources Institute), Rome

    Google Scholar 

  27. Garrity DP (2004) Agroforestry and the achievement of the millennium development goals. Agrofor Syst 61:5–17. doi:10.1023/B:AGFO.0000028986.37502.7c

    Article  Google Scholar 

  28. Geburek T (2005) Genetic diversity in forest trees—its importance and potential human impact. In: Geburek T, Turok J (eds) Conservation and management of forest genetic resources in Europe. Arbora Publishers, Zvolen, pp 437–463

    Google Scholar 

  29. Geburek T, Konrad H (2008) Why the conservation of forest genetic resources has not worked. Conserv Biol 22:267–274. doi:10.1111/j.1523-1739.2008.00900.x

    PubMed  Article  Google Scholar 

  30. Gentry AH, Vasquez R (1988) Where have all the Ceibas gone? A case history of mismanagement of a tropical forest resource. For Ecol Manag 23:73–76. doi:10.1016/0378-1127(88)90015-1

    Article  Google Scholar 

  31. Gigord L, Lavigne C, Shykoff JA (1998) Partial self-incompatibility and inbreeding depression in a native tree species of La Reunion (Indian Ocean). Oecologia 117:342–352. doi:10.1007/s004420050667

    Article  Google Scholar 

  32. Gil L, Fuentes-Utrilla P, Soto A, Teresa Cervera M, Collada C (2004) English elm is a 2,000-year-old Roman clone. Nature 431:1053

    PubMed  Article  CAS  Google Scholar 

  33. Graudal L, Lillesø J-PB (2007) Experiences and future prospects for tree seed supply in agricultural development support—based on lessons learnt in Danida supported programmes, 1965–2005. The Ministry of Foreign Affairs of Demark, Copenhagen

    Google Scholar 

  34. Hajjar R, Jarvis DI, Gemmill-Herren B (2008) The utility of crop genetic diversity in maintaining ecosystem services. Agric Ecosyst Environ 123:261–270. doi:10.1016/j.agee.2007.08.003

    Article  Google Scholar 

  35. Hamrick JL, Godt MJW, Sherman-Broyles SL (1992) Factors influencing levels of genetic diversity in woody plant species. New For 6:95–124. doi:10.1007/BF00120641

    Google Scholar 

  36. Hansson B, Westerberg L (2002) On the correlation between heterozygosity and fitness in natural populations. Mol Ecol 11:2467–2474. doi:10.1046/j.1365-294X.2002.01644.x

    PubMed  Article  Google Scholar 

  37. Hardner CM, Potts BM (1997) Post-dispersal selection following mixed mating in Eucalyptus regnans. Evol Int J Org Evol 51:103–111. doi:10.2307/2410964

    Google Scholar 

  38. Harlan JR (1975) Crops and man. The American Society of Agronomy and the Crop Science Society of America, Madison

    Google Scholar 

  39. Hellin J, Higman S (2005) Crop diversity and livelihood security in the Andes. Dev Pract 15:165–174. doi:10.1080/09614520500041344

    Article  Google Scholar 

  40. Hodge GR, Dvorak WS, Urueña H, Rosales L (2002) Growth, provenance effects and genetic variation of Bombacopsis quinata in field tests in Venezuela and Colombia. For Ecol Manag 158:273–289. doi:10.1016/S0378-1127(00)00720-9

    Article  Google Scholar 

  41. Holding C, Omondi W (eds) (1998) Evolution of provision of tree seed in extension programmes: case studies from Kenya and Uganda. SIDA Technical Report No. 19. Regional Land Management Unit, Swedish International Development Cooperation Agency, Nairobi

  42. Hollingsworth PM, Dawson IK, Goodall-Copestake WP, Richardson JE, Weber JC, Sotelo-Montes C, Pennington RT (2005) Do farmers reduce genetic diversity when they domesticate tropical trees? A case study from Amazonia. Mol Ecol 14:497–501. doi:10.1111/j.1365-294X.2005.02431.x

    PubMed  Article  CAS  Google Scholar 

  43. Jamnadass R, Hanson J, Poole J, Hanotte O, Simons TJ, Dawson IK (2005) High differentiation among populations of the woody legume Sesbania sesban in sub-Saharan Africa: implications for conservation and cultivation during germplasm introduction into agroforestry systems. For Ecol Manag 210:225–238. doi:10.1016/j.foreco.2005.02.033

    Article  Google Scholar 

  44. Jamnadass R, Lowe AJ, Dawson IK (2008) Genetic variation in tropical indigenous fruit trees: information from molecular markers and lessons for practical application. Trop Plant Biol (submitted)

  45. Janzen DH (1986) Blurry catastrophes. Oikos 47:1–2. doi:10.2307/3565912

    Article  Google Scholar 

  46. Jennings SB, Brown ND, Boshier DH, Whitmore TC, Lopes J do CA (2001) Ecology provides a pragmatic solution to the maintenance of genetic diversity in sustainable managed tropical rain forests. For Ecol Manag 154:1–10. doi:10.1016/S0378-1127(00)00637-X

    Article  Google Scholar 

  47. Kelly BA, Hardy OJ, Bouvet J-M (2004) Temporal and spatial genetic structure in Vitellaria paradoxa (shea tree) in an agroforestry system in southern Mali. Mol Ecol 13:1231–1240. doi:10.1111/j.1365-294X.2004.02144.x

    PubMed  Article  CAS  Google Scholar 

  48. Kindt R (2002) Methodology for tree species diversification planning in African agroecosystems. PhD thesis, University of Gent, Gent

  49. Kindt R, Lengkeek AG (1999) Tree diversity on farm—use it or lose it. In: agricultural biodiversity conservation. Proceedings of a workshop held in Nairobi, Kenya. Intermediate Technology Development Group East Africa, Nairobi, pp 75–85

  50. Kindt R, Lillesø J-PB, Mbora A, Muriuki J, Wambugu C, Frost W, Beniest J, Aithal A, Awimbo J, Rao S, Holding-Anyonge C (2006a) Tree seed for farmers: a toolkit and reference source. The World Agroforestry Centre (ICRAF), Nairobi

    Google Scholar 

  51. Kindt R, Van Damme P, Simons AJ, Beeckman H (2006b) Planning tree species diversification in Kenya based on differences in tree species composition between farms. I. Analysis of tree uses. Agrofor Syst 67:215–228. doi:10.1007/s10457-005-1703-2

    Article  Google Scholar 

  52. Kindt R, Van Damme P, Simons AJ, Beeckman H (2006c) Planning tree species diversification in Kenya based on differences in tree species composition between farms. II. Analysis of tree niches. Agrofor Syst 67:229–241. doi:10.1007/s10457-005-3824-z

    Article  Google Scholar 

  53. Kindt R, Van Damme P, Simons AJ (2006d) Tree diversity in western Kenya: using profiles to characterise richness and evenness. Biodivers Conserv 15:1253–1270. doi:10.1007/s10531-005-0772-x

    Article  Google Scholar 

  54. Kirschenmann FL (2007) Potential for a new generation of biodiversity in agroecosystems of the future. Agron J 99:373–376. doi:10.2134/agronj2006.0104

    Article  Google Scholar 

  55. Koelewijn HP, Koski V, Savolainen O (1999) Magnitude and timing of inbreeding depression in Scots pine (Pinus sylvestris L.). Evol Int J Org Evol 53:758–768. doi:10.2307/2640716

    Google Scholar 

  56. Leakey RRB (2007) Domestication and marketing of novel crops. In: Scherr SJ, McNeely JA (eds) Farming with nature: the science and practice of ecoagriculture. Island Press, Washington DC, pp 83–102

    Google Scholar 

  57. Leakey RRB, Page T (2006) The ‘ideotype concept’ and its application to the selection of ‘AFTP’ cultivars. For Trees Livelihoods 16:5–16

    Google Scholar 

  58. Leakey RRB, Schreckenberg K, Tchoundjeu Z (2003) The participatory domestication of West African indigenous fruits. Int For Rev 5:338–347

    Google Scholar 

  59. Leakey RRB, Tchoundjeu Z, Smith RI, Munro RC, Fondoun J-M, Kengue J, Anegbeh PO, Atangana AR, Waruhiu AN, Asaah E, Usoro C, Ukafor V (2004) Evidence that subsistence farmers have domesticated indigenous fruits (Dacryodes edulis and Irvingia gabonensis) in Cameroon and Nigeria. Agrofor Syst 60:101–111. doi:10.1023/B:AGFO.0000013259.95628.22

    Article  Google Scholar 

  60. Leakey RRB, Tchoundjeu Z, Schreckenberg K, Shackleton SE, Shackleton CM (2005) Agroforestry tree products (AFTPs): targeting poverty reduction and enhanced livelihoods. Int J Agric Sustain 3:1–23

    Google Scholar 

  61. Leakey RRB, Tchoundjeu Z, Schreckenberg K, Simons AJ, Shackleton S, Mander M, Wynberg R, Shackleton C, Sullivan C (2007) Trees and markets for agroforestry tree products: targeting poverty reduction and enhanced livelihoods. In: Garrity D, Okono A, Parrott M, Parrott S (eds) World agroforestry into the future. The World Agroforestry Centre (ICRAF), Nairobi, pp 11–22

    Google Scholar 

  62. Ledig FT (1992) Human impacts on genetic diversity on forest ecosystems. Oikos 63:87–108. doi:10.2307/3545518

    Article  Google Scholar 

  63. Lengkeek AG (2003) Diversity makes a difference: farmers managing inter- and intra- specific tree species diversity in Meru, Kenya. PhD thesis, Wageningen University, Wageningen

  64. Lengkeek AG, Carsan S (2004) The process of a participatory tree domestication project in Meru, Kenya. Dev Pract 14:445–451

    Google Scholar 

  65. Lengkeek AG, Jaenicke H, Dawson IK (2005a) Genetic bottlenecks in agroforestry systems: results of tree nursery surveys in East Africa. Agrofor Syst 63:149–155. doi:10.1007/s10457-004-9155-7

    Article  Google Scholar 

  66. Lengkeek AG, Kindt R, van der Maesen LJG, Simons AJ, van Oijen DCC (2005b) Tree density and germplasm source in agroforestry ecosystems in Meru, Mount Kenya. Genet Resour Crop Evol 52:709–721. doi:10.1007/s10722-003-6021-9

    Article  Google Scholar 

  67. Lengkeek AG, Muchugi Mwangi AM, Agufa CAC, Ahenda JO, Dawson IK (2006) Comparing genetic diversity in agroforestry systems with natural forest: a case study of the important timber tree Vitex fischeri in central Kenya. Agrofor Syst 67:293–300. doi:10.1007/s10457-005-5830-6

    Article  Google Scholar 

  68. Lowe AJ, Boshier D, Ward M, Bacles CFE, Navarro C (2005) Genetic resource impacts of habitat loss and degradation; reconciling empirical evidence and predicted theory for neotropical trees. Heredity 95:255–273. doi:10.1038/sj.hdy.6800725

    PubMed  Article  CAS  Google Scholar 

  69. Maranz S, Wiesman Z (2003) Evidence for indigenous selection and distribution of the shea tree, Vitellaria paradoxa, and its potential significance to prevailing parkland savanna tree patterns in sub-Saharan Africa north of the equator. J Biogeogr 30:1505–1516. doi:10.1046/j.1365-2699.2003.00892.x

    Article  Google Scholar 

  70. McNeely JA (2004) Nature vs. nurture: managing relationships between forests, agroforests and wild biodiversity. Agrofor Syst 61:155–165. doi:10.1023/B:AGFO.0000028996.92553.ea

    Article  Google Scholar 

  71. McNeely JA, Scherr SJ (2001) Common ground, common future: how ecoagriculture can help feed the world and save wild biodiversity. The World Conservation Union (IUCN), Gland, Switzerland and Future Harvest, Washington

    Google Scholar 

  72. Miller RP, Nair PKR (2006) Indigenous agroforestry systems in Amazonia: from prehistory to today. Agrofor Syst 66:151–164. doi:10.1007/s10457-005-6074-1

    Article  Google Scholar 

  73. Miller AJ, Schaal BA (2005) Domestication of a Mesoamerican cultivated fruit tree, Spondias purpurea. Proc Natl Acad Sci USA 102:12801–12806. doi:10.1073/pnas.0505447102

    PubMed  Article  CAS  Google Scholar 

  74. Miller AJ, Schaal BA (2006) Domestication and the distribution of genetic variation in wild and cultivated populations of the Mesoamerican fruit tree Spondias purpurea L. (Anacardiaceae). Mol Ecol 15:1467–1480. doi:10.1111/j.1365-294X.2006.02834.x

    PubMed  Article  CAS  Google Scholar 

  75. Nason JD, Hamrick JL (1997) Reproductive and genetic consequences of forest fragmentation: two case studies of neotropical canopy trees. J Hered 88:264–276

    Google Scholar 

  76. Nathan I, Shrestha KB, Jha PK, Suvedi S (2005) Commercial distribution of tree seed in small bags—results from a pilot and action research project in Nepal. Working Paper No. 9, Development and Environment, Forest and Landscape Denmark, Hørsholm

  77. Nill D, Böhnert E (2006) Value chains for the conservation of biological diversity for food and agriculture. Potatoes in the Andes, Ethiopian coffee, Argan oil from Morocco and grasscutters in West Africa. Deutsche Gesellschaft für Technische Zusammenarbeit, Eschborn. Germany and the Global Facilitation Unit for Underutilized Species, Rome

    Google Scholar 

  78. O’Neill GA, Dawson IK, Sotelo-Montes C, Guarino L, Guariguata M, Current D, Weber JC (2001) Strategies for genetic conservation of trees in the Peruvian Amazon. Biodivers Conserv 10:837–850. doi:10.1023/A:1016644706237

    Article  Google Scholar 

  79. Reed DH, Frankham R (2003) Correlation between fitness and genetic diversity. Conserv Biol 17:230–237. doi:10.1046/j.1523-1739.2003.01236.x

    Article  Google Scholar 

  80. Reusch TBH, Ehlers A, Hämmerli A, Worm B (2005) Ecosystem recovery after climatic extremes enhanced by genotypic diversity. Proc Natl Acad Sci USA 102:2826–2831. doi:10.1073/pnas.0500008102

    PubMed  Article  CAS  Google Scholar 

  81. Rochon C, Margolis HA, Weber JC (2007) Genetic variation in growth of Guazuma crinita (Mart.) trees at an early age in the Peruvian Amazon. For Ecol Manag 243:291–298. doi:10.1016/j.foreco.2007.03.025

    Article  Google Scholar 

  82. Rodan BD, Newton AC, Verissimo A (1992) Mahogany conservation: status and policy initiatives. Environ Conserv 19:331–342

    Article  Google Scholar 

  83. Rowe R, Cronk Q (1995) Applying molecular techniques to plant conservation: screening genes for survival. Plant Talk 1:18–19

    Google Scholar 

  84. Sanou H, Lovett PN, Bouvet J-M (2005) Comparison of quantitative and molecular variation in agroforestry populations of the shea tree (Vitellaria paradoxa C.F. Gaertn) in Mali. Mol Ecol 14:2601–2610. doi:10.1111/j.1365-294X.2005.02601.x

    PubMed  Article  CAS  Google Scholar 

  85. Schroth G, da Mota MSS (2004) The role of agroforestry in biodiversity conservation in the tropics: a synthesis of evidence. Paper presented at the International Ecoagriculture Conference and Practitioners’ Fair, held in Nairobi, Kenya. The World Agroforestry Centre (ICRAF), Nairobi, September–October 2004

  86. Scott JC (1998) Seeing like a state—how certain schemes to improve the human condition have failed. Yale University Press, New Haven

    Google Scholar 

  87. Simons AJ, Jaenicke H, Tchoundjeu Z, Dawson I, Kindt R, Oginosako Z, Lengkeek A, De Grande A (2000) The future of trees is on farm: tree domestication in Africa. In: Krishnapillay B, Soepadmo E, Lotfy Arshad N, Wong A, Appanah S, Wan Chik S, Manokaran N, Lay Tong H, Kean Choon K (eds) Forests and society: the role of research. Proceedings of the XXIst IUFRO World Congress, held in Kuala Lumpur, Malaysia, Sub-plenary Sessions vol 1, IUFRO Secretariat, Vienna and the Forest Research Institute Malaysia, Malaysia, pp 752–760, August 2000

  88. Smale M, Mar I, Jarvis DI (eds) (2002) The economics of conserving agricultural biodiversity on-farm: research methods developed from IPGRI’s global project ‘strengthening the scientific basis of in situ conservation of agricultural biodiversity’. Bioversity International (formerly the International Plant Genetic Resources Institute), Rome

    Google Scholar 

  89. Sokol KA, Greenwood MS, Livingston WH (2004) Impacts of long-term diameter-limit harvesting on residual stands of Red Spruce in Maine. North J Appl For 21:69–73

    Google Scholar 

  90. Sotelo-Montes C, Vidaurre H, Weber JC (2003) Variation in stem-growth and branch-wood traits among provenances of Calycophyllum spruceanum Benth. from the Peruvian Amazon. New For 26:1–16. doi:10.1023/A:1024425519480

    Google Scholar 

  91. Sotelo-Montes C, Hernández R, Beaulieu J, Weber JC (2006) Genetic variation and correlations between growth and wood density of Calycophyllum spruceanum Benth. at an early age in the Peruvian Amazon. Silvae Genet 55:217–228

    Google Scholar 

  92. Stacy EA (2001) Cross-fertility in two tropical tree species: evidence of inbreeding depression within populations and genetic divergence among populations. Am J Bot 88:1041–1051. doi:10.2307/2657086

    PubMed  Article  Google Scholar 

  93. Steffan-Dewenter I, Kessler M, Barkmann J, Bos MM, Buchori D, Erasmi S, Faust H, Gerold G, Glenk K, Gradstein SR, Guhardja E, Harteveld M, Hertel D, Hohn P, Kappas M, Kohler S, Leuschner C, Maertens M, Marggraf R, Migge-Kleian S, Mogea J, Pitopang R, Schaefer M, Schwarze S, Sporn SG, Steingrebe A, Tjitrosoedirdjo SS, Tjitrosoemito S, Twele A, Weber R, Woltmann L, Zeller M, Tscharntke T (2007) Tradeoffs between income, biodiversity, and ecosystem functioning during tropical rainforest conversion and agroforestry intensification. Proc Nat Acad Sci USA 104:4973–4978

    PubMed  Article  CAS  Google Scholar 

  94. Tata MHL, van Noordwijk M (2008) Trees, ectomycorrhizal dependence and regeneration strategies in rubber agroforests and other forest-derived vegetation in Jambi, Sumatra, Indonesia. For Ecol Manag (submitted)

  95. van der Steeg RP, Remington T, Grum M, Kemigisha E (2004) Seed vouchers and fairs and agrobiodiversity in Western Uganda. In: Sperling L, Remington T, Haugen JM, Nagoda S (eds) Addressing seed security in disaster response: linking relief with development. International Center for Tropical Agriculture, Cali, pp 29–44

    Google Scholar 

  96. van Oijen DCC (2002) Will the spirit of nGai survive? A tree survey on ethnobotany, conservation potential and biomass on 35 farms in Meru, Kenya. MSc practical report, Wageningen University, Wageningen

  97. Vaughan M, Hoffman Black S (2006) Enhancing nest sites for native bee crop pollinators. Agroforestry note 34. USDA National Agroforestry Center, Lincoln

    Google Scholar 

  98. Ward M, Dick CW, Lowe AJ (2005) To self, or not to self… A review of outcrossing and pollen-mediated gene flow in neotropical trees. Heredity 95:246–254. doi:10.1038/sj.hdy.6800712

    PubMed  Article  CAS  Google Scholar 

  99. Weber JC, Sotelo-Montes C (2005) Variation and correlations among stem growth and wood traits of Calycophyllum spruceanum Benth. from the Peruvian Amazon. Silvae Genet 54:31–41

    Google Scholar 

  100. Weber JC, Sotelo-Montes C (2008) Geographic variation in tree growth and wood density of Guazuma crinita Mart. in the Peruvian Amazon. New For (in press)

  101. Weber JC, Labarta Chávarri RL, Sotelo-Montes C, Brodie AW, Cromwell E, Schreckenberg K, Simons AJ (1997) Farmers’ use and management of tree germplasm: case studies from the Peruvian Amazon Basin. In: Simons AJ, Kindt R, Place F (eds) Policy aspects of tree germplasm demand and supply. Proceedings of an international workshop. The World Agroforestry Centre (ICRAF), Nairobi, pp 57–63

  102. Weber JC, Sotelo-Montes C, Vidaurre H, Dawson IK, Simons AJ (2001) Participatory domestication of agroforestry trees: an example from the Peruvian Amazon. Dev Pract 11:425–433. doi:10.1080/09614520120066710

    Article  Google Scholar 

  103. Weber JC, Larwanou M, Abasse TA, Kalinganire A (2008) Growth and survival of Prosopis africana provenances related to rainfall gradients in the West African Sahel. For Ecol Manag (submitted)

  104. Whitham TG, Bailey JK, Schweitzer JA, Shuster SM, Bangert RK, LeRoy CJ, Lonsdorf EV, Allan GJ, DiFazio SP, Potts BM, Fischer DG, Gehring CA, Lindroth RL, Marks JC, Hart SC, Wimp GM, Wooley SC (2006) A framework for community and ecosystem genetics: from genes to ecosystems. Nat Rev Genet 7:510–523. doi:10.1038/nrg1877

    PubMed  Article  CAS  Google Scholar 

  105. Williams JW, Jackson ST, Kutzbach JE (2007) Projected distributions of novel and disappearing climates by 2100 AD. Proc Natl Acad Sci USA 104:5738–5742. doi:10.1073/pnas.0606292104

    PubMed  Article  CAS  Google Scholar 

  106. Wily LA (2003) Participatory forest management in Africa: an overview of progress and issues. In: second international workshop on participatory forestry in Africa. Defining the way forward: sustainable livelihoods and sustainable forest management through participatory forestry, Arusha, United Republic of Tanzania, 18–22 February 2002, FAO, Rome, pp 31–58

  107. Wright S (1931) Evolution in Mendelian populations. Genetics 16:97–159

    PubMed  CAS  Google Scholar 

  108. Wu HK, Matheson AC, Spencer D (1998a) Inbreeding in Pinus radiata. I. The effects of inbreeding on growth, survival and variance. Theor Appl Genet 97:1256–1268. doi:10.1007/s001220051018

    Article  Google Scholar 

  109. Wu HK, Matheson AC, Spencer D (1998b) Inbreeding in Pinus radiata. II. Time course of inbreeding depression and effect on growth curve. N Z J For Sci 28:123–139

    Google Scholar 

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Acknowledgments

We gratefully acknowledge the contributions of colleagues who participated in workshops in Cameroon, Kenya and Uganda in 2005 during the development of a Global Environment Facility project proposal on this topic. In addition, the authors benefited greatly from corresponding with a number of individuals during the development of this manuscript, including Sarah Applewhite, Luigi Guarino, Michael Hermann, Hannah Jaenicke, Roeland Kindt, Roger Leakey, Jens-Peter Lillesø and Meine van Noordwijk. Thanks are also given to the two anonymous reviewers whose comments improved the manuscript.

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Correspondence to Ian K. Dawson.

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Dawson, I.K., Lengkeek, A., Weber, J.C. et al. Managing genetic variation in tropical trees: linking knowledge with action in agroforestry ecosystems for improved conservation and enhanced livelihoods. Biodivers Conserv 18, 969 (2009). https://doi.org/10.1007/s10531-008-9516-z

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Keywords

  • Agroforestry ecosystems
  • Biodiversity management
  • Genetic variation
  • Tropical trees