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Altitudinal variation and conservation priorities of vegetation along the Great Rift Valley escarpment, northern Ethiopia

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Abstract

Understanding plant species distribution patterns along environmental gradients is fundamental to managing ecosystems, particularly when habitats are fragmented due to intensive human land-use pressure. To assist management of the remaining vegetation of the Eastern Afromontane Biodiversity Hotspot, plant species richness and diversity patterns were analyzed along the main elevation gradient (1,000–2,760 m) of the Great Rift Valley escarpment in northern Ethiopia, using 29 plots established at 100-m elevation intervals. A total of 129 vascular plant species belonging to 59 families was recorded. Species richness and diversity showed a hump-shaped relationship with elevation, peaking at mid-elevation (1,900–2,200 m). Beta diversity values indicated medium species turnover along the elevation gradient and were lowest at mid-elevation. Elevation strongly partitioned the plant communities (r = 0.98; P < 0.001). Four plant communities were identified along the elevation gradient: Juniperus procera–Clutia lanceolata community (2,400–2,760 m), Abutilon longicuspe–Calpurnia aurea community (1,900–2,300 m), Dracaena ombet–Acacia etbaica community (1,400–1,800 m), and Acacia mellifera–Dobera glabra community (1,000–1,300 m). To optimize conservation of species and plant communities, it is recommended that a conservation corridor be established along the elevation gradient that includes all four plant communities. This strategy—in contrast to creating single isolated reserves in zones with high species richness—is necessary for the habitat protection of species with narrow elevational ranges, in particular the globally endangered Nubian dragon tree (Dracaena ombet).

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References

  • Aerts R, van Overtveld K, Deckers J, Haile M, Hermy M, Muys B (2006) Species composition and diversity of small Afromontane forest fragments in northern Ethiopia. Plant Ecol 187:127–142

    Article  Google Scholar 

  • Aerts R, Lerouge F, November E, Lens I, Hermy M, Muys B (2008) Land rehabilitation and the conservation of birds in a degraded Afromontane landscape in northern Ethiopia. Biodivers Conserv 17:53–69

    Article  Google Scholar 

  • Aerts R, Hundera K, Berecha G, Gijbels P, Baeten M, van Mechelen M, Hermy M, Muys B, Honnay O (2011) Semi-forest coffee cultivation and the conservation of Ethiopian Afromontane rainforest fragments. For Ecol Manag 261:1034–1041

    Article  Google Scholar 

  • Aynekulu E, Kassawmar T, Tamene L (2008) Applicability of ASTER imagery in mapping land use/cover as a basis for biodiversity studies in drylands of northern Ethiopia. Afr J Ecol 46(Suppl. 1):19–23

    Article  Google Scholar 

  • Aynekulu E, Denich M, Tsegaye D (2009) Regeneration response of Juniperus procera and Olea europaea subsp. cuspidata to exclosure in a dry Afromontane forest in northern Ethiopia. Mt Res Dev 29:143–152

    Article  Google Scholar 

  • Aynekulu E, Denich M, Tsegaye D, Aerts R, Neuwirth B, Boehmer HJ (2011) Dieback affects forest structure in a dry Afromontane forest in northern Ethiopia. J Arid Environ 75:499–503

    Article  Google Scholar 

  • Blundo C, Malizia LR, Blake JG, Brown AD (2012) Tree species distribution in Andean forests: influence of regional and local factors. J Trop Ecol 28:83–95

    Article  Google Scholar 

  • Boehmer HJ (2011) Vulnerability of tropical montane rain forest ecosystems due to climate change. In: Brauch HG, Oswald Spring Ú, Mesjasz C, Grin J, Kameri-Mbote P, Chourou B, Dunay P, Birkmann J (eds) Coping with global environmental change, disasters and security—threats, challenges, vulnerabilities and risks. Hexagon series on human and environmental security and peace, vol 5, Springer, Berlin, 789–802. doi:10.1007/978-3-642-17776-7_46

  • Bongers F, Poorter L, Hawthorne WD, Sheil D (2009) The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity. Ecol Lett 12:798–805

    Article  PubMed  Google Scholar 

  • Breshears DD, Cobb NS, Rich PM, Price KP, Allen CD, Balice RG, Romme WH, Kastens JH, Floyd ML, Belnap J, Anderson JJ, Myers OB, Weyer CW (2005) Regional vegetation die-off in response to global-change-type drought. Proc Natl Acad Sci USA 102:15144–15148

    Article  PubMed  CAS  Google Scholar 

  • Brinkmann K, Patzelt A, Dickhoefer U, Schlecht E, Buerkert A (2009) Vegetation patterns and diversity along an altitudinal and a grazing gradient in the Jabal al Akhdar mountain range of northern Oman. J Arid Environ 73(11):1035–1045

    Article  Google Scholar 

  • Burgess ND, Butynski TM, Cordeiro NJ, Doggart N, Fjeldså J, Kilahama F, Loader SP, Lovett JC, Mbilinyi B, Menegon M, Moyer DC, Nashanda EA, Perkin A, Atanley WT, Stuart SN (2007) The biological importance of the eastern Arc mountains of Tanzania and Kenya. Biol Conserv 134:209–231

    Article  Google Scholar 

  • Clarke KR (1993) Non-parametric multivariate analyses of changes in community structure. Aust J Ecol 18:117–143

    Article  Google Scholar 

  • Conservation International (2007) Biodiversity hotspots [Online]. http://www.biodiversityhotspots.org/xp/Hotspots/hotspots_by_region/Pages/default.aspx. Accessed 09 April 2012

  • Darbyshire I, Lamb H, Umer M (2003) Forest clearance and regrowth in northern Ethiopia during the last 3,000 years. Holocene 13:537–546

    Article  Google Scholar 

  • Dudley N, Parish J (2006) Closing the gap. Creating ecologically representative protected area systems: a guide to conducting the gap assessments of protected area systems for the convention on biological diversity. Technical series No. 24. Secretariat of the Convention on Biological Diversity, Montreal, Canada

  • Dufrêne M, Legendre P (1997) Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol Monogr 67:345–366

    Google Scholar 

  • Eilu G, Hafashimana DIN, Kasenene JM (2004) Density and species diversity of trees in four tropical forests of the Albertine rift, western Uganda. Divers Distrib 10:303–312

    Article  Google Scholar 

  • Ferrier S (2002) Mapping spatial pattern in biodiversity for regional conservation planning: where to from here? Syst Biol 51:331–363

    Article  PubMed  Google Scholar 

  • Fjeldsa J (2007) How broad-scale studies of patterns and processes can guide conservation planning in Africa. Conserv Biol 21:659–667

    Article  PubMed  Google Scholar 

  • Friis I (1986) The forest vegetation of Ethiopia. Acta Univ Ups Symb Ups XX1:31–47

    Google Scholar 

  • Friis I (1992) Forests and forest trees of northeast tropical Africa: their natural habitats and distribution patterns in Ethiopia, Djibouti and Somalia. Her Majesty’s Stationery Office, London

    Google Scholar 

  • Friis I, Demissew S (2001) Vegetation maps of Ethiopia and Eritrea. A review of existing maps and the need for a new map for the flora of Ethiopia and Eritrea. In: Friis IB, Ryding O (eds) Proceedings of the 3rd international symposium on the flora of Ethiopia and Eritrea at the Carlsberg Academy, Copenhagen. Biodiversity Research in the Horn of Africa Region, pp 399–439

  • Friis I, Demissew S, van Breugel P (2010) Atlas of the potential vegetation of Ethiopia, Biologiske Skrifter, vol 58. The Royal Danish Academy of Science and Letters, Copenhagen

  • Gebreegziabher Z (1999) Dessa’a protected area: an assessment of human impact, evolutionary pattern and options for sustainable management. UNESCO MAB (Man and the Biosphere)

  • Gole TW, Borsch T, Denich M, Teketay D (2008) Floristic composition and environmental factors characterizing coffee forests in southwest Ethiopia. For Ecol Manag 255:2138–2150

    Article  Google Scholar 

  • Greenway PJ (1973) A classification of the vegetation of east Africa. Kirkia 9:1–68

    Google Scholar 

  • Grytnes JA, Beaman JH (2006) Elevational species richness patterns for vascular plants on Mount Kinabalu, Borneo. J Biogeogr 33:1838–1849

    Article  Google Scholar 

  • Haila Y, Margules CR (1996) Survey research in conservation biology. Ecography 19:323–331

    Google Scholar 

  • Hedberg O (1969) Evolution and speciation in a tropical high mountain flora. Biol J Linn Soc Lond 1:135–148

    Article  Google Scholar 

  • Hemp A (2006) Continuum or zonation? Altitudinal gradients in the forest vegetation of Mt. Kilimanjaro. Plant Ecol 184:27–42

    Article  Google Scholar 

  • Hillebrand H, Bennett D, Cadotte MW (2008) Consequences of dominance: a review of evenness effects on local and regional ecosystem processes. Ecology 89(6):1510–1520

    Article  PubMed  Google Scholar 

  • Huston M, Gilbert L (1996) Consumer diversity and secondary production. In: Orians GH, Dirzo R, Cushman JH (eds) Biodiversity and ecosystem processes in tropical forests. Springer, New York, pp 33–47

    Chapter  Google Scholar 

  • Kassen R, Buckling A, Bell G, Rainey PB (2000) Diversity peaks at intermediate productivity in a laboratory microcosm. Nature 406:507–512

    Article  Google Scholar 

  • Kessler M (2000) Elevational gradients in species richness and endemism of selected plant groups in the central Bolivian Andes. Plant Ecol 149:181–193

    Article  Google Scholar 

  • Kreft H, Jetz W (2007) Global patterns and determinants of vascular plant diversity. Proc Natl Acad Sci USA 104:5925–5930

    Article  PubMed  CAS  Google Scholar 

  • Kurschner H, Kilian N, Hein P (2008) The Tarchonantho camphoratae–Oleetum cuspidatae ass. nov.—an Afromontane evergreen sclerophyllous community of the Arabian peninsula with strong relationships to East Africa. Phytocoenologia 38:85–106

    Article  Google Scholar 

  • Laurance WF, Useche DC, Shoo LP, Herzog SK, Kessler M, Escobar F, Brehm G, Axmacher JC, Chen I-C, Gámez LA, Hietz P, Fiedler K, Pyrcz T, Jolf W, Merkord CL, Cardelus C, Marshall AR, Ah-Peng C, Aplet GH, Arizmendi MDC, Baker WJ, Barone J, Brühl, CA, Bussmann RW, Cicuzza D, Eilu G, Favila ME, Hemp A, Hemp C, Homeier J, Hurtado J, Jankowski J, Kattán G, Kluge J, Krömer T, Lees DC, Lehnert M, Longino JT, Lovett J, Martin PH, Patterson, BD, Pearson RG, Peh KS-H, Richardson B, Richardson M, Samways MJ, Senbeta F, Smith TB, Utteridge TMA, Watkins JE, Wilson R, Williams SE, Thomas CD (2011) Global warming, elevational ranges and the vulnerability of tropical biota. Biol Cons 144:548–557

  • Logan WEM (1946) An Introduction to the Forests of Central and Southern Ethiopia. Imperial Forestry Institute, University of Oxford, Oxford

    Google Scholar 

  • Lomolino MV (2001) Elevation gradients of species-density: historical and prospective views. Glob Ecol Biogeogr 10:3–13

    Article  Google Scholar 

  • Lovett JC (1988) Endemism and affinities of the Tanzanian montane forest flora. In: Goldblatt P, Lowry PP (eds) Proceedings of the eleventh plenary of the Association for the Taxonomic Study of Tropical Africa. Monographs in systematic botany from the Missouri botanical garden, vol 25, pp 591–598

  • Lovett JC (1993) Temperate and tropical floras in the mountains of eastern Tanzania. Opera bot 121:217–227

    Google Scholar 

  • Lovett JC (1999) Tanzanian forest tree plot diversity and elevation. J Trop Ecol 121:217–227

    Google Scholar 

  • Lovett JC, Wasser SK (1993) Biogeography & ecology of the rainforest of eastern Africa. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Lovett JC, Rudd S, Taplin J, Frimodt-moller C (2000) Patterns of plant diversity in Africa south of the Sahara and their implications for conservation management. Biodivers Conserv 9:37–46

    Article  Google Scholar 

  • Lyaruu HV, Eliapenda S, Backeus I (2000) Floristic, structural and seed bank diversity of a dry Afromontane forest at Mafai, central Tanzania. Biodivers Conserv 9:241–263

    Article  Google Scholar 

  • Margules CR, Pressey RL, Williams PH (2007) Representing biodiversity: data and procedures for identifying priority areas for conservation. J Biosci 27:309–326

    Article  Google Scholar 

  • Martin TG, Chade`s I, Arcese P, Marra PP, Possingham HP, Ryan Norris D (2007) Optimal conservation of migratory species. PLoS ONE 2(8):e751

    Article  PubMed  Google Scholar 

  • McCune B, Grace JB (2002) Analysis of ecological communities. MjM Software Design, USA

  • McCune B, Mefford MJ (1999) PC-ORD multivariate analysis of Ecological data. Version 5.0. MjM software. Gleneden Beach, Oregon

  • Mekuria W, Aynekulu E (2011) Exclosure land management restores soil properties of degraded communal grazing lands in northern Ethiopia. Land Degrad Dev. doi:10.1002/ldr.1146

    Google Scholar 

  • Mittelbach GG, Steiner CF, Scheiner SM, Gross KL, Reynolds HL, Waide RB, Willing MR, Dodson SI, Gouch L (2001) What is the observed relationship between species richness and productivity? Ecology 82:2381–2396

    Article  Google Scholar 

  • Mittermeier RA, Myers N, Thomsen JB (1998) Biodiversity hotspots and major tropical wilderness areas: approaches to setting conservation priorities. Conserv Biol 12:516–520

    Article  Google Scholar 

  • Munro RN, Deckers J, Haile M, Grove AT, Poesen J, Nyssen J (2008) Soil landscapes, land cover change and erosion features of the central plateau region of Tigrai, Ethiopia: photo-monitoring with an interval of 30 years. CATENA 75:55–64

    Article  Google Scholar 

  • Mwaura F, Kaburu HM (2009) Spatial variability in woody species richness along altitudinal gradient in a lowland-dryland site, Lokapel Turkana, Kenya. Biodivers Conserv 18:19–32

    Article  Google Scholar 

  • Newmark WD (2002) Conserving biodiversity in east African forests: a study of the eastern Arc Mountains. Ecological studies, vol 155. Springer, Berlin

  • Nogués-Bravo D, Araújo MB, Romdal T, Rahbek C (2008) Scale effects and human impact on the elevational species richness gradients. Nature 253:216–219

    Article  Google Scholar 

  • Nyssen J, Poesen J, Moeyersons J, Deckers J, Haile M, Lang A (2004) Human impact on the environment in the Ethiopian and Eritrean highlands-a state of the art. Earth Sci Rev 64:273–320

    Article  Google Scholar 

  • Oommen MA, Shanker K (2005) Elevational species richness patterns emerge from multiple local mechanisms in Himalayan woody plants. Ecology 86(11):3039–3347

    Article  Google Scholar 

  • Pichi-sermolli R (1957) Una carta geobotanica dell’Africa Orientale. Webbia 13:15–132

    Google Scholar 

  • Rahbek C (1995) The elevational gradient of species richness: a uniform pattern? Ecography 18(2):200–205

    Article  Google Scholar 

  • Reid WV (1998) Biodiversity hotspots. Trends Ecol Evol 13:275–280

    Article  PubMed  CAS  Google Scholar 

  • Ren H-B, Niu S-K, Zhang L-Y, Ma K-P (2006) Distribution of vascular plant species richness along an elevational gradient in the Dongling Mountains, Beijing, China. J Integr Plant Biol 48:153–160

    Article  Google Scholar 

  • Sánchez-gonzález A, López-mata L (2005) Plant species richness and diversity along an altitudinal gradient in the Sierra Nevada, Mexico. Divers Distrib 11:567–575

    Article  Google Scholar 

  • Schmitt CB, Denich M, Demissew S, Friis I, Boehmer HJ (2010) Floristic diversity in fragmented Afromontane rainforests: altitudinal variation and conservation importance. Appl Veg Sci 13:291–304

    Google Scholar 

  • Senbeta F, Schmitt CB, Denich M, Demissew S, Vlek PLG, Preisinger H, Woldemariam T, Teketay D (2005) The diversity and distribution of lianas in the Afromontane rainforests of Ethiopia. Divers Distrib 11:443–452

    Article  Google Scholar 

  • Tikssa M, Bekele T, Kelbessa E (2010) Plant community distribution and variation along the Awash river corridor in the main Ethiopian rift. Afr J Ecol 48:121–128

    Article  Google Scholar 

  • Tsegaye D, Moe SR, Haile M (2009) Livestock browsing, not water limitations, contributes to recruitment failure of Dobera glabra in semiarid Ethiopia. Rangeland Ecol Manag 62(6):540–549

    Article  Google Scholar 

  • Tsegaye D, Moe SR, Vedeld PO, Aynekulu E (2010a) Land-use/cover dynamics in arid and semi-arid rangelands of northern Afar, Ethiopia. Agric Ecosyst Environ 139:174–180

  • Tsegaye D, Hail M, Moe SR (2010b) The effect of land use on the recruitment and population structure of the important food and fodder plant, Dobera glabra (Forssk.) Poir. in northern Afar, Ethiopia. J Arid Environ 74(9):1074–1082

    Article  Google Scholar 

  • Vázquez JAG, Givnish TJ (1998) Altitudinal gradients in tropical forest composition, structure, and diversity in the Sierra de Manantlán, Jalisco, México. J Ecol 86:999–1020

    Article  Google Scholar 

  • von Breitenbach F (1963) The indigenous trees of Ethiopia, 2nd edn. Ethiopian Forestry Association, Addis Ababa, Ethiopia, p 305

    Google Scholar 

  • Whittaker RJ, Willis KJ, Field R (2003) Climatic–energetic explanations of diversity: a macroscopic perspective. In: Blackburn TM, Gaston KJ (eds) Macroecology: concepts and consequences. Cambridge University Press, Cambridge, pp 107–129

    Google Scholar 

  • Wilson MV, Shmida A (1984) Measuring beta diversity with presence-absence data. J Ecol 12:1055–1064

    Google Scholar 

  • Woldemariam T (2003) Vegetation of the Yayu forest in SW Ethiopia: impacts of human use and implications for in situ conservation of wild coffea arabica L. populations. Ecology and development Series No. 10. Center for Development Research, University of Bonn

  • Woldewahid G, van Der Werf W, Sykora K, Abate T, Mostofa B, van Huis A (2007) Description of plant communities on the Red Sea coastal plain of Sudan. J Arid Environ 68(1):113–331

    Article  Google Scholar 

  • Woldu Z, Feoli E, Nigatu L (1989) Partitioning an elevation gradient of vegetation from southeastern Ethiopia by probabilistic methods. Vegetatio 81:189–198

    Article  Google Scholar 

  • World Conservation Monitoring Centre (1998) Dracaena ombet. In: IUCN 2011. IUCN red list of threatened species. version 2011.2. www.iucnredlist.org. Accessed 09 April 2012

  • Yirdaw E (2001) Diversity of naturally-regenerated native woody species in forest plantations in the Ethiopian highlands. New For 22(3):159–177

    Article  Google Scholar 

  • Zhao S, Fang J (2006) Patterns of species richness for vascular plants in China’s nature reserves. Divers Distrib 12:364–372

    Article  Google Scholar 

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Acknowledgments

The first author is grateful to the German Academic Exchange Service (DAAD) for financial support and Mekelle University for logistical support during the fieldwork.

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Authors and Affiliations

  1. World Agroforestry Centre (ICRAF), United Nations Avenue, P.O. Box 30677-00100, Nairobi, Kenya

    Ermias Aynekulu & Tor-Gunnar Vågen

  2. College of Dryland Agriculture and Natural Resources, Mekelle University, P.O. Box 231, Mekelle, Ethiopia

    Ermias Aynekulu & Kindeya Gebrehiwot

  3. Division Forest, Nature and Landscape, University of Leuven, Celestijnenlaan 200E-2411, 3001, Leuven, Belgium

    Raf Aerts & Pieter Moonen

  4. Center for Development Research (ZEF), University of Bonn, Walter-Flex-Str. 3, 53113, Bonn, Germany

    Manfred Denich

  5. International Water Management Institute (IWMI), P.O. Box 4199, Ban Nongviengkham, Xaythany District, Vientiane, Laos

    Wolde Mekuria

  6. Interdisciplinary Latin America Center (ILZ) University of Bonn, Walter-Flex-Str. 3, 53113, Bonn, Germany

    Hans Juergen Boehmer

  7. Chair for Strategic Landscape Planning and Management, Department of Ecology and Ecosystem Management, Technical University of Munich, Emil-Ramann-Str. 6, 85350, Freising-Weihenstephan, Germany

    Hans Juergen Boehmer

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  1. Ermias Aynekulu
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  2. Raf Aerts
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  3. Pieter Moonen
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  4. Manfred Denich
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  5. Kindeya Gebrehiwot
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  6. Tor-Gunnar Vågen
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  7. Wolde Mekuria
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  8. Hans Juergen Boehmer
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Correspondence to Ermias Aynekulu.

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Aynekulu, E., Aerts, R., Moonen, P. et al. Altitudinal variation and conservation priorities of vegetation along the Great Rift Valley escarpment, northern Ethiopia. Biodivers Conserv 21, 2691–2707 (2012). https://doi.org/10.1007/s10531-012-0328-9

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