, Volume 32, Issue 4, pp 967–983 | Cite as

Variation in wood basic density within and between tree species and site conditions of exclosures in Tigray, northern Ethiopia

  • Mengesteab Hailu UbuyEmail author
  • Tron Eid
  • Ole Martin Bollandsås
Original Article
Part of the following topical collections:
  1. Biomechanics


Key Message

A first database with wood basic density values for tree species growing in exclosures in Tigray was developed. The values from the database are likely to give reliable biomass estimates also if they are applied outside the currently studied exclosures.


Wood basic density (wbd) is a principal measure for characterizing wood. The main objective of this study was to obtain wbd values for tree species growing in exclosures in the Tigray region, northern Ethiopia. Stem discs for wbd determination were collected from 305 trees among the 50 most abundant tree species located in six exclosures covering wide ranges of growing conditions. The main achievement of this study was the development of a first database with wbd values for tree species growing in the exclosures of Tigray. The mean wbd value of the 50 tree species included in this database was 0.707 g cm− 3 with a range between 0.400 and 1.154 g cm− 3. Since wide ranges of growing conditions and the most abundant tree species in the region were included, this database constitutes a solid basis for biomass and carbon estimation, and is valuable for aiding forest management decisions. The wbd values may also potentially be included in the Global Wood Density database since only a few of the 50 tree species are currently available there. For the tree species with the largest within-species wbd ranges, the ranges between exclosures are much smaller than the within-species ranges. This implies that it is likely to arrive at reliable biomass estimates also if existing wbd values are applied outside the currently studied exclosures. Still, it is recommended that future studies should test biomass models under different assumptions for determination of wbd to evaluate the effects on biomass estimation and that the wbd database should be enriched by including additional sites to capture larger ranges in growing conditions and more tree species.


Exclosures Wood basic density Stem discs Generalized additive model Biomass estimation 



The study was funded through the project “Steps toward sustainable forest management with the local communities in Tigray, northern Ethiopia (ETH 13/0018)” under the Norwegian Programme for Capacity Development in Higher Education and Research for Development (NORHED). This is a collaboration project between Mekelle University, Department of Land Resources Management and Environmental Protection, Ethiopia and Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management. Thanks go to all data collectors, particularly to Mr. Yemane Adane for his special help with field and laboratory work, to Dr. Emiru Birhane for facilitating the fieldwork, to Dr. Meley Mekonen Rannestad for commenting on an early draft of this paper and to Ellen Jessica Kayendeke for assisting in developing a map for the study sites.

Compliance with ethical standards

Conflict of interest

We declare that we have no conflict of interest.


  1. Aerts R, Nyssen J, Haile M (2009) On the difference between “exclosures” and “enclosures” in ecology and the environment. J Arid Environ 73:762–763. CrossRefGoogle Scholar
  2. Agrawal A, Nepstad D, Chhatre A (2011) Reducing emissions from deforestation and forest degradation. Annu Rev Environ Resour 36:373–396. CrossRefGoogle Scholar
  3. Babulo B (2007) Economic valuation and management of common-pool resources: the case of exclosures in the highlands of Tigray, Northern Ethiopia. Dissertation, Katholieke Universiteit LeuvenGoogle Scholar
  4. Baker TR, Phillips OL, Malhi Y, Almeida S, Arroyo L, Di Fiore A, Erwin T, Killeen TJ, Laurance SG, Laurance WF, Lewis SL, Lloyd J, Monteagudo A, Neill DA, Patino S, Pitman NCA, Silva JNM, Martinez RV (2004) Variation in wood density determines spatial patterns in Amazonian forest biomass. Glob Chang Biol 10:545–562. CrossRefGoogle Scholar
  5. Balana BB, Muys B, Haregeweyn N, Descheemaeker K, Deckers J, Poesen J, Nyssen J, Mathijs E (2012) Cost-benefit analysis of soil and water conservation measure: the case of exclosures in northern Ethiopia. For Pol Econ 15:27–36. CrossRefGoogle Scholar
  6. Bastin G, Ludwig J, Eager R, Liedloff A, Andison R, Cobiac M (2003) Vegetation changes in a semiarid tropical savanna, northern Australia: 1973–2002. Rangel J 25:3–19. CrossRefGoogle Scholar
  7. Bastin JF, Fayolle A, Tarelkin Y, Van den Bulcke J, de Haulleville T, Mortier F, Beeckman H, Van Acker J, Serckx A, Bogaert J, De Cannière C (2015) Wood specific gravity variations and biomass of central African tree species: the simple choice of the outer wood. PloS One 10:e0142146. Scholar
  8. Bein E, Habte B, Jaber A, Birnie A, Tengnäs (1996) Useful trees and shrubs in Eritrea: Identification, propagation and management for agricultural and pastoral communities. Technical handbook, Regional Soil Conservation Unit, Kenya, NairobiGoogle Scholar
  9. Bekele T, Bimie A, Tengnas B (2007) Useful trees and shrubs for Ethiopia: identification, propagation and management for agricultural and pastoral communities. SIDA, Kenya, NairobiGoogle Scholar
  10. Chave J, Andalo C, Brown S, Cairns MA, Chambers JQ, Eamus D, Fölster H, Fromard F, Higuchi N, Kira T, Lescure JP, Nelson BW, Oqawa H, Puig H, Rièra B, Yamakura T (2005) Tree allometry and improved estimation of carbon stocks and balance in tropical forests. Oecologia 145:87–99. CrossRefPubMedGoogle Scholar
  11. Chave J, Muller-Landau HC, Baker TR, Easdale TA, Steege HT, Webb CO (2006) Regional and phylogenetic variation of wood density across 2456 neotropical tree species. Ecol Appl 16:2356–2367.[2356:RAPVOW]2.0.CO;2CrossRefPubMedGoogle Scholar
  12. Chave J, Coomes D, Jansen S, Lewis SL, Swenson NG, Zanne AE (2009) Towards a worldwide wood economics spectrum. Ecol Lett 12:351–366. CrossRefPubMedGoogle Scholar
  13. Chave J, Réjou-Méchain M, Búrquez A, Chidumayo E, Colgan MS, Delitti WB, Duque A, Eid T, Fearnside PM, Goodman RC, Henry M, Martínez-Yrízar A, Mugasha WA, Muller-Landau HC, Mencuccini M, Nelson BW, Ngomanda A, Nogueira EM, Ortiz-Malavassi E, Pélissier R, Ploton P, Ryan CM, Saldarriaga JG, Vieilledent G (2014) Improved allometric models to estimate the above ground biomass of tropical forests. Glob Chang Biol 20:3177–3190. CrossRefPubMedGoogle Scholar
  14. Colgan MS, Swemmer T, Asner GP (2014) Structural relationships between form factor, wood density, and biomass in African savanna woodlands. Trees 28:91–102. CrossRefGoogle Scholar
  15. Curran TJ, Gersbach LN, Edwards W, Krockenberger AK (2008) Wood density predicts plant damage and vegetative recovery rates caused by cyclone disturbance in tropical rainforest tree species of North Queensland, Australia. Austral Ecol 33:442–450. CrossRefGoogle Scholar
  16. Dumail JF, Castéra P, Morlier P (1998) Hardness and basic density variation in the juvenile wood of maritime pine. Ann For Sci 55:911–923. CrossRefGoogle Scholar
  17. Ebrahimi M, Khosravi H, Rigi M (2016) Short-term grazing exclusion from heavy livestock rangelands affects vegetation cover and soil properties in natural ecosystems of southeastern Iran. Ecol Eng 95:10–18. CrossRefGoogle Scholar
  18. Edwards S, Demissew S, Hedberg I (1997) Flora of Ethiopia and Eritrea: Volume 6. Hydrocharitaceae to Arecaceae. National Herbarium, Biology Department, Addis Ababa University, EthiopiaGoogle Scholar
  19. Fazzini M, Bisci C, Billi P (2015) The climate of Ethiopia. In Billi P (ed) Landscapes and landforms of Ethiopia, World geomorphological landscapes. Springer, Dordrecht.
  20. Fearnside PM (1997) Wood density for estimating forest biomass in Brazilian Amazonia. For Ecol Manag 90:59–87. CrossRefGoogle Scholar
  21. Fichtl R, Adi A (1994) Honeybee flora of Ethiopia. Margraf Verlag, WeikersheimGoogle Scholar
  22. Gebremedhin B, Pender J, Tesfay G (2003) Community natural resource management: the case of woodlots in northern Ethiopia. Environ Dev Econ 8:129–148. CrossRefGoogle Scholar
  23. Githiomi JK, Kariuki JG (2010) Wood basic density of Eucalyptus grandis from plantations in Central Rift Valley, Kenya: variation with age, height level and between sapwood and heartwood. J Trop For Sci 22:281–286Google Scholar
  24. Goussanou CA, Guendehou S, Assogbadjo AE, Kaire M, Sinsin B, Cuni-Sanchez A (2016) Specific and generic stem biomass and volume models of tree species in a West African tropical semi-deciduous forest. Silva Fenn 50:2 1474. CrossRefGoogle Scholar
  25. Griscom HP, Ashton MS (2011) Restoration of dry tropical forests in Central America: a review of pattern and process. For Ecol Manag 261:1564–1579. CrossRefGoogle Scholar
  26. Hacke UG, Sperry JS, Pockman WT, Davis SD, McCulloh KA (2001) Trends in wood density and structure are linked to prevention of xylem implosion by negative pressure. Oecologia 126:457–461. CrossRefPubMedGoogle Scholar
  27. Hastie TJ, Tibshirani RJ (1990) Generalized additive models. CRC, Boca RatonGoogle Scholar
  28. Henry M, Besnard A, Asante WA, Eshun J, Adu-Bredu S, Valentini R, Bernoux M, Saint-André L (2010) Wood density, phytomass variations within and among trees, and allometric equations in a tropical rainforest of Africa. For Ecol Manag 260:1375–1388. CrossRefGoogle Scholar
  29. IPCC (2014) Revised Supplementary Methods and Good Practice Guidance Arising from the Kyoto Protocol. Intergovernmental panel on climate change, GenevaGoogle Scholar
  30. Jacobsen AL, Pratt RB, Ewers FW, Davis SD (2007) Cavitation resistance among 26 chaparral species of southern California. Ecol Monogr 77:99–115. CrossRefGoogle Scholar
  31. James G, Witten D, Hastie TJ, Tibshirani RJ (2013) An introduction to statistical learning: with Applications in R. Springer, New YorkCrossRefGoogle Scholar
  32. Kataki R, Konwer D (2002) Fuelwood characteristics of indigenous tree species of north-east India. Biomass Bioenerg 22:433–437. CrossRefGoogle Scholar
  33. Le Houerou HN (2000) Restoration and rehabilitation of arid and semiarid Mediterranean ecosystems in North Africa and West Asia: a review. Arid Soil Res Rehabil 14:3–14. CrossRefGoogle Scholar
  34. Lemenih M, Bekele T (2004) Effect of age on calorific value and some mechanical properties of three Eucalyptus species grown in Ethiopia. Biomass Bioenerg 27:223–232. CrossRefGoogle Scholar
  35. Lemenih M, Kassa H (2014) Re-greening Ethiopia: history, challenges and lessons. Forests 5:1896–1909. CrossRefGoogle Scholar
  36. Machado JS, Louzada JL, Santos AJ, Nunes L, Anjos O, Rodrigues J, Simões RM, Pereira H (2014) Variation of wood density and mechanical properties of blackwood (Acacia melanoxylon R. Br.). Mater Des 56:975–980. CrossRefGoogle Scholar
  37. Meinzer FC (2003) Functional convergence in plant responses to the environment. Oecologia 134:1–11. CrossRefPubMedGoogle Scholar
  38. Mekuria W, Veldkamp E, Corre MD, Haile M (2011) Restoration of ecosystem carbon stocks following exclosure establishment in communal grazing lands in Tigray, Ethiopia. Soil Sci Soc Am J 75:246–256. CrossRefGoogle Scholar
  39. Mseddi K, Al-Shammari A, Sharif H, Chaieb M (2016) Plant diversity and relationships with environmental factors after rangeland exclosure in arid Tunisia. Turk J Bot 40:287–297. CrossRefGoogle Scholar
  40. Muller-Landau HC (2004) Interspecific and inter-site variation in wood specific gravity of tropical trees. Biotropica 36:20–32. CrossRefGoogle Scholar
  41. Nedessa B, Ali J, Nyborg I (2005) Exploring ecological and socio-economic issues for the improvement of area enclosure management. A case study from Ethiopia. Dryland Coordination Group Report 38Google Scholar
  42. Nelson BW, Mesquita R, Pereira JL, De Souza SGA, Batista GT, Couto LB (1999) Allometric regressions for improved estimate of secondary forest biomass in the central Amazon. For Ecol Manag 117:149–167. CrossRefGoogle Scholar
  43. Njana MA, Meilby H, Eid T, Zahabu E, Malimbwi RE (2016) Importance of tree basic density in biomass estimation and associated uncertainties: a case of three mangrove species in Tanzania. Ann For Sci 73:1073–1087. CrossRefGoogle Scholar
  44. Nygård R, Elfving B (2000) Stem basic density and bark proportion of 45 woody species in young savanna coppice forests in Burkina Faso. Ann For Sci 57:143–153. CrossRefGoogle Scholar
  45. Osazuwa-Peters OL, Wright SJ, Zanne AE (2014) Radial variation in wood specific gravity of tropical tree species differing in growth-mortality strategies. Am J Bot 101:803–811. CrossRefPubMedGoogle Scholar
  46. Patino S, Lloyd J, Paiva R, Baker TR, Quesada C, Mercado LM, Schmerler J, Schwarz M, Santos A, Aguilar A et al (2009) Branch xylem density variations across the Amazon Basin. Biogeosciences 6:545–568. CrossRefGoogle Scholar
  47. Plourde BT, Boukili VK, Chazdon RL (2015) Radial changes in wood specific gravity of tropical trees: inter-and intraspecific variation during secondary succession. Funct Ecol 29:111–120. CrossRefGoogle Scholar
  48. Poorter L, Wright SJ, Paz H, Ackerly DD, Condit R, Ibarra-Manríquez G, Harms KE, Licona JC, Martínez-Ramos M, Mazer SJ, Muller-Landau HC, Peña-Claros M, Webb CO, Wright IJ (2008) Are functional traits good predictors of demographic rates? Evidence from five neotropical forests. Ecology 89:1908–1920. CrossRefPubMedGoogle Scholar
  49. R Core Team (2015) R: a language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar
  50. Ramananantoandro T, Rafidimanantsoa HP, Ramanakoto MF (2015) Forest aboveground biomass estimates in a tropical rainforest in Madagascar: new insights from the use of wood specific gravity data. J For Res 26:47–55. CrossRefGoogle Scholar
  51. Ramananantoandro T, Ramanakoto MF, Rajoelison GL, Randriamboavonjy JC, Rafidimanantsoa HP (2016) Influence of tree species, tree diameter and soil types on wood density and its radial variation in a mid-altitude rainforest in Madagascar. Ann For Sci. CrossRefGoogle Scholar
  52. Robinson AP, Lane SE, Thérien G (2011) Fitting forestry models using generalized additive models: a taper model example. Can J For Res 41:1909–1916. CrossRefGoogle Scholar
  53. Sagarese SR, Frisk MG, Cerrato RM, Sosebee KA, Musick JA, Rago PJ (2014) Application of generalized additive models to examine ontogenetic and seasonal distributions of spiny dogfish (Squalus acanthias) in the Northeast (US) shelf large marine ecosystem. Can J Fish Aquat Sci 71:847–877. CrossRefGoogle Scholar
  54. Seyoum Y, Birhane E, Hagazi N, Esmael N, Mengistu T, Kassa H (2015) Enhancing the role of the forestry sector in building climate resilient green economy in Ethiopia: strategy for scaling up effective forest management practices in Tigray National Regional State with emphasis on area exclosures. Center for International Forestry research Ethiopia Office, Addis AbabaGoogle Scholar
  55. Stegen JC, Swenson NG, Valencia R, Enquist BJ, Thompson J (2009) Above-ground forest biomass is not consistently related to wood density in tropical forests. Glob Ecol Biogeogr 18:617–625. CrossRefGoogle Scholar
  56. Suzuki E (1999) Diversity in specific gravity and water content of wood among Bornean tropical rainforest trees. Ecol Res 14:211–224. CrossRefGoogle Scholar
  57. Swenson NG, Enquist BJ (2007) Ecological and evolutionary determinants of a key plant functional trait: wood density and its community-wide variation across latitude and elevation. Am J Bot 94:451–459. CrossRefPubMedGoogle Scholar
  58. UN-REDD (2016) Ethiopia’s forest reference level submission to the UNFCCC. Accessed Oct 2017
  59. Van Gelder HA, Poorter L, Sterck FJ (2006) Wood mechanics, allometry, and life-history variation in a tropical rain forest tree community. New Phytol 171:367–378. CrossRefPubMedGoogle Scholar
  60. Wang S, Wilkes A, Zhang Z, Chang X, Lang R, Wang Y, Niu H (2011) Management and land use change effects on soil carbon in northern China’s grasslands: a synthesis. Agric Ecosyst Environ 142:329–340. CrossRefGoogle Scholar
  61. Wassenberg M, Chiu HS, Guo W, Spiecker H (2015) Analysis of wood density profiles of tree stems: incorporating vertical variations to optimize wood sampling strategies for density and biomass estimations. Trees 29:551–561. CrossRefGoogle Scholar
  62. Wiemann MC, Williamson GB (1989) Radial gradients in the specific gravity of wood in some tropical and temperate trees. For Sci 35:197–210Google Scholar
  63. Wiemann MC, Williamson GB (2002) Geographic variation in wood specific gravity: effects of latitude, temperature, and precipitation. Wood Fiber Sci 34:96–107Google Scholar
  64. Wiemann MC, Williamson GB (2012) Density and specific gravity metrics in biomass research. USDA Forest Service, Forest products Laboratory, General Technical Report, FPL-GTR-208, March 2012Google Scholar
  65. Williamson GB, Wiemann MC (2010) Measuring wood specific gravity correctly. Am J Bot 97:519–524. CrossRefPubMedGoogle Scholar
  66. Wintle BA, Elith J, Potts JM (2005) Fauna habitat modelling and mapping a review and case study in the Lower Hunter Central Coast region of NSW. Austral Ecol 30:719–738. CrossRefGoogle Scholar
  67. Witt GB, Noël MV, Bird MI, Beeton RB, Menzies NW (2011) Carbon sequestration and biodiversity restoration potential of semi-arid mulga lands of Australia interpreted from long-term grazing exclosures. Agric Ecosyst Environ 141:108–118. CrossRefGoogle Scholar
  68. Wood SN (2006) Generalized additive models: an introduction with R. Chapman and Hall/CRC, USACrossRefGoogle Scholar
  69. Yami M, Mekuria W, Hauser M (2013) The effectiveness of village bylaws in sustainable management of community-managed exclosures in Northern Ethiopia. Sustain Sci 8:73–86. CrossRefGoogle Scholar
  70. Zanne AE, Lopez-Gonzalez G, Coomes DA, Ilic J, Jansen S, Lewis SL, Miller RB, Swenson NG, Wiemann MC, Chave J (2009) Data from: towards a worldwide wood economics spectrum. Dryad Digital Repository.
  71. Zobel BJ, Van Buijtenen JP (2012) Wood variation: its causes and control. Springer, BerlinGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Mengesteab Hailu Ubuy
    • 1
    • 2
    Email author
  • Tron Eid
    • 1
  • Ole Martin Bollandsås
    • 1
  1. 1.Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
  2. 2.Department of Land Resources Management and Environmental ProtectionMekelle UniversityMekelleEthiopia

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