, Volume 25, Issue 3, pp 345–354 | Cite as

Dendrochronology in the dry tropics: the Ethiopian case

  • T. H. G. Wils
  • U. G. W. Sass-Klaassen
  • Z. Eshetu
  • A. Bräuning
  • A. Gebrekirstos
  • C. Couralet
  • I. Robertson
  • R. Touchan
  • M. Koprowski
  • D. Conway
  • K. R. Briffa
  • H. Beeckman


Dendrochronology is developing outside temperate and boreal regions. Over the past decade substantial progress has been made in Mediterranean and wet tropical regions. However, research in dry tropical regions, notably those of sub-Saharan Africa, has remained fragmentary. Here, we try to identify the unique challenges and opportunities of dendrochronology in the dry tropics. First, we briefly review the status of dendrochronology outside temperate and boreal regions with an emphasis on sub-Saharan Africa. Subsequently, we focus upon one of those areas where dendrochronology in the dry tropics is at the forefront of scientific advance: Ethiopia. A detailed review of tree ring studies in the lowlands and highlands highlights the complexity of ring formation and made us identify four major types of growth ring expression: anatomically not distinct rings, multiple rings per year, annual rings and multiple missing rings. This complex tree growth behaviour is associated with large-scale variations in precipitation regime (unimodal to multimodal) and relatively small-scale variations in tree sensitivity to water availability. Literature results are used to develop a scheme that can be used to predict differences in growth ring formation along gradients in these two factors. Because of the exceptional growth sensitivity of and the importance of local site conditions (topography, biological factors, etc.) for most trees sampled, those growing at the limits of their ecological amplitude are prone to possess multiple rings per year or multiple missing rings. In such circumstances, site selection should not always take place at the limits of the ecological amplitude of a species, but may sometimes have to be diverted to more mesic environments. Successful studies are now appearing, such as those reporting correlations between tree ring chronologies and Blue Nile river flows.


Acacia Juniperus procera Ring formation Tree rings Wood anatomy 


  1. Anchukaitis KJ, Evans MN, Wheelwright NT, Schrag DP (2008) Stable isotope chronology and climate signal calibration in neotropical montane cloud forest trees. J Geophys Res 113:G03030. doi:10.1029/2007JG000613 CrossRefGoogle Scholar
  2. Bräuning A, Mantwill B (2004) Summer temperature and summer monsoon history on the Tibetan plateau during the last 400 years recorded by tree rings. Geophys Res Lett 31:L24205. doi:10.1029/2004GL020793 CrossRefGoogle Scholar
  3. Bréda N, Huc R, Granier A, Dreyer E (2006) Temperate forest trees and stands under severe drought: a review of ecophysiological responses, adaptation processes and long-term consequences. Ann For Sci 63:625–644CrossRefGoogle Scholar
  4. Brienen RJW, Zuidema PA (2005) Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis. Oecologia 146:1–12PubMedCrossRefGoogle Scholar
  5. Briffa KR, Russell-Smith A (1986) Dendroclimatic pilot study in Ethiopia. Climatic Research Unit, University of East Anglia, Norwich, p 26Google Scholar
  6. Buckley BM, Anchukaitis KJ, Penny D, Fletcher R, Cook ER, Sano M, Nam LC, Wichienkeeo A, Minh TT, Hong TM (2010) Climate as a contributing factor in the demise of Angkor, Cambodia. PNAS 107:6748–6752PubMedCrossRefGoogle Scholar
  7. Cherubini P, Gartner BL, Tognetti R, Bräker OU, Schoch W, Innes JL (2003) Identification, measurement and interpretation of tree rings in woody species from mediterranean climates. Biol Rev 78:119–148PubMedCrossRefGoogle Scholar
  8. Conway D, Schipper ELF (2010) Adaptation to climate change in Africa: challenges and opportunities identified from Ethiopia. Glob Environ Chang. doi:10.1016/j.gloenvcha.2010.07.013
  9. Conway D, Brooks N, Briffa KR, Desta S, Merrin PD, Jones PD (1997) Exploring the potential for dendroclimatic analysis in northern Ethiopia. University of East Anglia, Norwich, p 38Google Scholar
  10. Conway D, Brooks N, Briffa KR, Merrin PD (1998) Historical climatology and dendroclimatology in the Blue Nile River basin, northern Ethiopia. In: Servat E, Hughes D, Fritsch JM, Hulme M (eds) Water resources variability in Africa during the XXth century, vol 252. IAHS Publications, pp 243–251Google Scholar
  11. Couralet C (2004) Growth and population dynamics of Juniperus procera in an Ethiopian dry afromontane forest: dendrochronology and matrix model. Forest Ecology and Forest Management, MSc thesis. Wageningen University, Wageningen, p 109Google Scholar
  12. Couralet C, Sass-Klaassen U, Sterck F, Bekele T, Zuidema PA (2005) Combining dendrochronology and matrix modelling in demographic studies: an evaluation for Juniperus procera in Ethiopia. For Ecol Manag 216:317–330CrossRefGoogle Scholar
  13. Couralet C, Sass-Klaassen U, Sahle Y, Sterck F, Bekele T, Bongers F (2007) Dendrochronological investigations on Juniperus procera from Ethiopian Dry Afromontane Forests. TRACE Dendrosymposium 2006. Forschungszentrum Jülich, pp 73–79Google Scholar
  14. Couralet C, Sterck FJ, Sass-Klaassen U, van Acker J, Beeckman H (2010) Species-specific growth responses to climate variations in understory trees of a Central African rainforest. Biotropica 42:503–511CrossRefGoogle Scholar
  15. D’Arrigo R, Abram N, Ummenhofer C, Palmer J, Mudelsee M (2010) Reconstructed streamflow for Citarum River, Java, Indonesia: linkages to tropical climate dynamics. Clim Dyn. doi:10.1007/s00382-009-0717-2
  16. De Luis M, Gričar J, Čufar K, Raventós J (2007) Seasonal dynamics of wood formation in Pinus halepensis from dry and semi-arid ecosystems in Spain. IAWA J 28:389–404Google Scholar
  17. Degefu W (1988) Some aspects of meteorological drought in Ethiopia. In: Glantz MH (ed) Drought and hunger in Africa: denying famine a future. Cambridge University Press, Cambridge, pp 23–36Google Scholar
  18. Deslauriers A, Rossi S, Anfodillo T (2007) Dendrometer and intra-annual tree growth: what kind of information can be inferred? Dendrochronologia 25:113–124CrossRefGoogle Scholar
  19. EMA (1988) National atlas of Ethiopia. Ethiopian Mapping Authority, Addis AbabaGoogle Scholar
  20. Eshete G, Ståhl G (1999) Tree rings as indicators of growth periodicity of acacias in the Rift Valley of Ethiopia. For Ecol Manag 116:107–117CrossRefGoogle Scholar
  21. Eshetu Z (2006) Dendroclimatological research in Ethiopia. Ethiopian Institute of Agricultural Research, Forestry Research Centre, Addis Ababa, p 19Google Scholar
  22. Esper J, Frank D, Büntgen U, Verstege A, Luterbacher J, Xoplaki E (2007) Long-term drought severity variations in Morocco. Geophys Res Lett 34:L17702. doi:10.1029/2007GL030844 CrossRefGoogle Scholar
  23. Fichtler E, Trouet V, Beeckman H, Coppin P, Worbes M (2004) Climatic signals in tree rings of Burkea africana and Pterocarpus angolensis from semiarid forests in Namibia. Trees-Struct Funct 18:442–451Google Scholar
  24. Fonti P, Von Arx G, García-González I, Eilmann B, Sass-Klaassen U, Gärtner H, Eckstein D (2009) Studying global change through plastic responses of xylem anatomy in tree rings. New Phytol 185:42–53PubMedCrossRefGoogle Scholar
  25. Fritts HC (1976) Tree rings and climate. Academic Press, LondonGoogle Scholar
  26. Gasse F (2000) Hydrological changes in the African tropics since the Last Glacial Maximum. Quat Sci Rev 19:189–211CrossRefGoogle Scholar
  27. Gebrekirstos A (2006) Stable carbon isotopes and plant water relations in the Acacia savanna woodlands of Ethiopia: implications for reforestation and paleoclimatic reconstructions. Cuvillier Verlag, GöttingenGoogle Scholar
  28. Gebrekirstos A, Van Noordwijk M, Neufeldt H, Mitlöhner R (2010) Relationships of stable carbon isotopes, plant water potential and growth: an approach to asses water use efficiency and growth strategies of dry land agroforestry species. Trees-Struct Funct. doi:10.1007/s00468-010-0467-0
  29. Gebrekirstos A, Teketay D, Fetene M, Mitlöhner R (2006) Adaptation of five co-occurring tree and shrub species to water stress and its implication in restoration of degraded lands. For Ecol Manag 229:259–267CrossRefGoogle Scholar
  30. Gebrekirstos A, Mitlöhner R, Teketay D, Worbes M (2008) Climate–growth relationships of the dominant tree species from semi-arid savanna woodland in Ethiopia. Trees-Struct Funct 22:631–641Google Scholar
  31. Gebrekirstos A, Worbes M, Teketay D, Fetene M, Mitlöhner R (2009) Stable carbon isotope ratios in tree rings of co-occurring species from semi-arid tropics in Africa: patterns and climatic signals. Global Planet Change 66:253–260CrossRefGoogle Scholar
  32. Gourlay ID (1995a) The definition of seasonal growth zones in some African Acacia species - a review. IAWA J 16:353–359Google Scholar
  33. Gourlay ID (1995b) Growth ring characteristics of some African Acacia species. J Trop Ecol 11:121–140CrossRefGoogle Scholar
  34. Heinrich I, Banks JCG (2006) Tree-ring anomalies in Toona ciliata. IAWA J 27:213–231Google Scholar
  35. Jacoby GC (1989) Overview of tree-ring analysis is tropical regions. IAWA Bull 10:99–108Google Scholar
  36. Jones PD, Briffa KR, Osborn TJ, Lough JM, van Ommen TD, Vinther BM, Luterbacher J, Wahl ER, Zwiers FW, Mann ME, Schmidt GA, Ammann CM, Buckley BM, Cobb KM, Esper J, Goosse H, Graham N, Jansen E, Kiefer T, Kull C, Kuttel M, Mosley-Thompson E, Overpeck JT, Riedwyl N, Schulz M, Tudhope AW, Villalba R, Wanner H, Wolff E, Xoplaki E (2009) High-resolution palaeoclimatology of the last millennium: a review of current status and future prospects. The Holocene 19:3–49CrossRefGoogle Scholar
  37. Kerkfoot O (1964) The distribution and ecology of Juniperus procera Endl. in East Central Africa, and its relationship to the genus Widdringtonia Endl. Kirkia 4:75–87Google Scholar
  38. Krepkowski J, Bräuning A, Gebrekirstos A, Strobl S (2010) Cambial growth dynamics and climatic control of different tree life forms in tropical mountain forest in Ethiopia. Trees-Struct Funct. doi:10.1007/s00468-010-0460-7
  39. Krishnamurthy RV, Epstein S (1985) Tree ring D/H ratio from Kenya, East Africa, and its palaeoclimatic significance. Nature 317:160–162CrossRefGoogle Scholar
  40. Lavender DP (1991) Measuring phenology and dormancy. In: Lassoie JP, Hinckley TM (eds) Techniques and approaches in forest tree ecophysiology. CRC, Boca Raton, pp 403–422Google Scholar
  41. Leblanc SG, Chen JM, Fernandes R, Deering DW, Conley A (2005) Methodology comparison for canopy structure parameters extraction from digital hemispherical photography in boreal forests. Agric For Meteorol 129:187–207CrossRefGoogle Scholar
  42. Martín-Benito D, Cherubini P, Del Río M, Cañellas I (2008) Growth response to climate and drought in Pinus nigra Arn. trees of different crown classes. Trees-Struct Funct 22:363–373Google Scholar
  43. Nicholson SE (2001) Climatic and environmental change in Africa during the last two centuries. Clim Res 17:123–144CrossRefGoogle Scholar
  44. Nicolini G, Tarchiani V, Saurer M, Cherubini P (2010) Wood-growth zones in Acacia seyal Delile in the Keita Valley, Niger: is there any climatic signal? J Arid Environ 74:355–359CrossRefGoogle Scholar
  45. Olago DO, Odada EO (2004) Palaeo-research in Africa: relevance to sustainable environmental management and significance for the future. In: Battarbee RW, Gasse F, Stickley CE (eds) Past climate variability through Europe and Africa. Springer, The Netherlands, pp 551–565CrossRefGoogle Scholar
  46. Pourtahmasi K, Parsapjouh D, Bräuning A, Esper J, Schweingruber FH (2007) Climatic analysis of pointer years in tree-ring chronologies from northern Iran and neighboring high mountain areas. Geoökodynamik 28:27–42Google Scholar
  47. Rossi S, Anfodillo T, Menardi R (2006) TREPHOR: a new tool for sampling microcores from tree stems. IAWA J 27:89–97Google Scholar
  48. Sass-Klaassen U, Couralet C, Sahle Y, Sterck FJ (2008a) Juniper from Ethiopia contains a large-scale precipitation signal. Int J Plant Sci 169:1057–1065CrossRefGoogle Scholar
  49. Sass-Klaassen U, Leuschner HH, Buerkert A, Helle G (2008b) Tree-ring analysis of Juniperus excelsa from the northern Oman mountains. TRACE Dendrosymposium 2007. Forschungszentrum Jülich, pp 99–108Google Scholar
  50. Schöngart J, Orthmann B, Hennenberg KJ, Porembski S, Worbes M (2006) Climate-growth relationships of tropical tree species in West Africa and their potential for climate reconstruction. Glob Chang Biol 12:1139–1150CrossRefGoogle Scholar
  51. Schweingruber FH, Eckstein D, Serre-Bachet F, Bräker OU (1990) Identification, presentation and interpretation of event years and pointer years in dendrochronology. Dendrochronologia 8:15–38Google Scholar
  52. Shao X, Xu Y, Yin Z-Y, Liang E, Zhu H, Wang S (2010) Climatic implications of a 3585-year tree-ring width chronology from the northeastern Qinghai-Tibetan Plateau. Quat Sci Rev 29:2111–2122CrossRefGoogle Scholar
  53. Stahle DW, Mushove PT, Cleaveland MK, Roig F, Haynes GA (1999) Management implications of annual growth rings in Pterocarpus angolensis from Zimbabwe. For Ecol Manag 124:217–229CrossRefGoogle Scholar
  54. Therrell MD, Stahle DW, Ries LP, Shugart HH (2006) Tree-ring reconstructed rainfall variability in Zimbabwe. Clim Dyn 26:677–685CrossRefGoogle Scholar
  55. Therrell MD, Stahle DW, Mukelabai MM, Shugart HH (2007) Age, and radial growth dynamics of Pterocarpus angolensis in southern Africa. For Ecol Manag 244:24–31CrossRefGoogle Scholar
  56. Touchan R, Anchukaitis KJ, Meko DM, Sabir M, Attalah S, Aloui A (2010) Spatiotemporal drought variability in northwestern Africa over the last nine centuries. Clim Dyn. doi:10.1007/s00382-010-0804-4
  57. Touchan R, Meko DM, Hughes MK (1999) A 396-year reconstruction of precipitation in southern Jordan. J Am Water Res 35:45–55Google Scholar
  58. Touchan R, Anchukaitis KJ, Meko DM, Attalah S, Baisan C, Aloui A (2008) Long term context for recent drought in northwestern Africa. Geophys Res Lett 35:L13705. doi:10.1029/2008GL034264 CrossRefGoogle Scholar
  59. Treydte KS, Schleser GH, Helle G, Frank DC, Winiger M, Haug GH, Esper J (2006) The twentieth century was the wettest period in northern Pakistan over the past millennium. Nature 440:1179–1182PubMedCrossRefGoogle Scholar
  60. Trouet V, Coppin P, Beeckman H (2006) Annual growth ring patterns in Brachystegia spiciformis reveal influence of precipitation on tree growth. Biotropica 38:375–382CrossRefGoogle Scholar
  61. Trouet V, Esper J, Graham NE, Baker A, Scourse JD, Frank DC (2009) Persistent positive North Atlantic Oscillation mode dominated the Medieval Climate Anomaly. Science 324:78–80PubMedCrossRefGoogle Scholar
  62. Trouet V, Esper J, Beeckman H (2010) Climate/growth relationships of Brachystegia spiciformis from the miombo woodland in south central Africa. Dendrochronologia 28:161–171CrossRefGoogle Scholar
  63. Umer M, Legesse D, Gasse F, Bonnefille R, Lamb HF, Leng MJ, Lamb AL (2004) Late Quaternary climate changes in the Horn of Africa. In: Battarbee RW, Gasse F, Stickley CE (eds) Past climate variability through Europe and Africa. Springer, The Netherlands, pp 159–180CrossRefGoogle Scholar
  64. Vaganov EA, Anchukaitis KJ, Evans MN (2010) How well understood are the processes that create dendroclimatic records? A mechanistic model of the climatic control on conifer tree-ring growth dynamics. In: Hughes MK, Swetnam TW, Diaz HF (eds) Dendroclimatology: progress and prospects. Springer, pp 37–76Google Scholar
  65. Verheyden A, Helle G, Schleser GH, Dehairs F, Beeckman H, Koedam N (2004a) Annual cyclicity in high-resolution stable carbon and oxygen isotope ratios in the wood of the mangrove tree Rhizophora mucronata. Plant Cell Environ 27:1525–1536CrossRefGoogle Scholar
  66. Verheyden A, Kairo JG, Beeckman H, Koedam N (2004b) Growth rings, growth ring formation and age determination in the mangrove Rhizophora mucronata. Ann Bot-London 94:59–66CrossRefGoogle Scholar
  67. Verschuren D (2004) Decadal and century-scale climate variability in tropical Africa during the past 2000 years. In: Battarbee RW, Gasse F, Stickley CE (eds) Past climate variability through Europe and Africa. Springer, The Netherlands, pp 139–158CrossRefGoogle Scholar
  68. Wassie A, Sterck FJ, Teketay D, Bongers F (2009) Tree regeneration in Ethiopian church forests of Ethiopia: effects of microsites and management. Biotropica 41:110–119CrossRefGoogle Scholar
  69. Wils THG (2007) Dendroclimatology on Juniperus procera in the upper Blue Nile and Tekeze basin. Quat Newsl 113:55–58Google Scholar
  70. Wils THG (2009) Isotope dendroclimatological studies on Juniperus procera from Ethiopia: towards a reconstruction of Blue Nile baseflow. School of the Environment and Society, PhD thesis. Swansea University, Swansea, p 364Google Scholar
  71. Wils THG, Eshetu Z (2007) Reconstructing the flow of the River Nile from Juniperus procera and Prunus africana tree rings (Ethiopia)—an explorative study on cross-dating and climate signal. TRACE Dendrosymposium 2006. Forschungszentrum Jülich, pp 277–284Google Scholar
  72. Wils THG, Eshetu Z, Koprowski M (2008) Reconstructing the flow of the River Nile from Juniperus procera tree rings and historical sources: dating the tree rings. Royal Geographical Society, London, p 44Google Scholar
  73. Wils THG, Robertson I, Eshetu Z, Sass-Klaassen UGW, Koprowski M (2009) Periodicity of growth rings in Juniperus procera from Ethiopia inferred from crossdating and radiocarbon dating. Dendrochronologia 27:45–58CrossRefGoogle Scholar
  74. Wils THG, Robertson I, Eshetu Z, Touchan R, Sass-Klaassen U, Koprowski M (2010a) Crossdating Juniperus procera from North Gondar, Ethiopia. Trees-Struct Funct. doi:10.1007/s00468-010-0475-0
  75. Wils THG, Robertson I, Eshetu Z, Koprowski M, Sass-Klaassen UGW, Touchan R, Loader NJ (2010b) Towards a reconstruction of Blue Nile baseflow from Ethiopian tree rings. The Holocene 20:837–848CrossRefGoogle Scholar
  76. Worbes M (1995) How to measure growth dynamics in tropical trees, a review. IAWA J 16:337–351Google Scholar
  77. Worbes M (2002) One hundred years of tree-ring research in the tropics—a brief history and an outlook to future challenges. Dendrochronologia 20:217–231CrossRefGoogle Scholar
  78. Worbes M, Junk WJ (1989) Dating tropical trees by means of 14C from bomb tests. Ecology 70:503–507CrossRefGoogle Scholar
  79. Worbes M, Staschel R, Roloff A, Junk WJ (2003) Tree ring analysis reveals age structure, dynamics and wood production of a natural forest stand in Cameroon. For Ecol Manag 173:105–123CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • T. H. G. Wils
    • 1
    • 2
    • 3
  • U. G. W. Sass-Klaassen
    • 4
  • Z. Eshetu
    • 5
  • A. Bräuning
    • 6
  • A. Gebrekirstos
    • 7
  • C. Couralet
    • 8
    • 9
  • I. Robertson
    • 1
  • R. Touchan
    • 10
  • M. Koprowski
    • 11
  • D. Conway
    • 12
  • K. R. Briffa
    • 13
  • H. Beeckman
    • 8
  1. 1.Department of Geography, School of the Environment and SocietySwansea UniversitySwanseaUK
  2. 2.Department of Geography, Institute for Teacher TrainingRotterdam University of Applied SciencesRotterdamThe Netherlands
  3. 3.Department of Geography, Institute for Teacher TrainingFontys University of Applied SciencesTilburgThe Netherlands
  4. 4.Forest Ecology and Forest Management Group, Centre of Ecosystem StudiesWageningen UniversityWageningenThe Netherlands
  5. 5.Forestry Research CentreEthiopian Institute of Agricultural ResearchAddis AbabaEthiopia
  6. 6.Institute of GeographyFriedrich-Alexander University of Erlangen-NürnbergErlangenGermany
  7. 7.International Centre for Research in Agroforestry (ICRAF), Global HeadquartersNairobiKenya
  8. 8.Laboratory for Wood Biology and XylariumRoyal Museum for Central Africa (RMCA)TervurenBelgium
  9. 9.Laboratory for Wood TechnologyGhent UniversityGhentBelgium
  10. 10.Laboratory of Tree-Ring ResearchUniversity of ArizonaTucsonUSA
  11. 11.Laboratory of Dendrochronology, Institute of Ecology and Environment Protection, Faculty of Biology and Earth ScienceNicolaus Copernicus UniversityToruńPoland
  12. 12.School of International DevelopmentUniversity of East AngliaNorwichUK
  13. 13.Climatic Research UnitUniversity of East AngliaNorwichUK

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