Elevation patterns of woody taxa richness in the evergreen Afromontane vegetation of Ethiopia
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摘要
Plant species distributions show patterns along elevation gradients. Regardless of the diverse Afromontane vegetation in Ethiopia(AFE), studies of elevation patterns of woody plants are limited and they are restricted to small areas or single/few Mountains. Moreover, there is no general consensus on the patterns of woody taxa distribution by elevation. The objectives of this study were to examine the elevation patterns of woody taxa richness and their relationship with elevation in the AFE. Data were collected and compiled from the Flora of Ethiopia and Eritrea(Vols. 1–7). About 5918 plant species of 243 families were examined and their elevational distributions were recorded. The distributional ranges of woody taxa were aggregated at 19 points(sites) at 100 m intervals starting from 1500 to 3400 m a.s.l. Single-factor analysis of variance(one-way ANOVA) was used to test the hypothesis that mean species richness of woody taxa decreases from the lower to the upper limit of AFE. Simple linear correlation and regression were used to show the relationships of woody taxa richness with elevation. We documented the presence of 505 woody taxa(441 species,31 subspecies and 33 varieties) representing 267 genera and 90 families in the AFE. In terms of habit, 279 taxa are shrubs, 178 are trees and 48 are lianas. The distribution of woody taxa(trees, shrubs and lianas) showed a slight increase at the lower portion and a monotonic decline with increasing elevation. Species richness of trees, shrubs and lianas was negatively and significantly correlated with elevation(r =-0.985,-0.984,-0.981, respectively; all p <0.001). Our hypothesis was accepted because mean richness significantly decreased from the lower to the upper limit of AFE(p <0.001). Generally, monotonic patterns of decline in richness were observed for trees, shrubs and lianas. The contribution of shrubs to total richness increased with increasing elevation whereas that of trees and lianas decreased.
Plant species distributions show patterns along elevation gradients. Regardless of the diverse Afromontane vegetation in Ethiopia(AFE), studies of elevation patterns of woody plants are limited and they are restricted to small areas or single/few Mountains. Moreover, there is no general consensus on the patterns of woody taxa distribution by elevation. The objectives of this study were to examine the elevation patterns of woody taxa richness and their relationship with elevation in the AFE. Data were collected and compiled from the Flora of Ethiopia and Eritrea(Vols. 1–7). About 5918 plant species of 243 families were examined and their elevational distributions were recorded. The distributional ranges of woody taxa were aggregated at 19 points(sites) at 100 m intervals starting from 1500 to 3400 m a.s.l. Single-factor analysis of variance(one-way ANOVA) was used to test the hypothesis that mean species richness of woody taxa decreases from the lower to the upper limit of AFE. Simple linear correlation and regression were used to show the relationships of woody taxa richness with elevation. We documented the presence of 505 woody taxa(441 species,31 subspecies and 33 varieties) representing 267 genera and 90 families in the AFE. In terms of habit, 279 taxa are shrubs, 178 are trees and 48 are lianas. The distribution of woody taxa(trees, shrubs and lianas) showed a slight increase at the lower portion and a monotonic decline with increasing elevation. Species richness of trees, shrubs and lianas was negatively and significantly correlated with elevation(r =-0.985,-0.984,-0.981, respectively; all p <0.001). Our hypothesis was accepted because mean richness significantly decreased from the lower to the upper limit of AFE(p <0.001). Generally, monotonic patterns of decline in richness were observed for trees, shrubs and lianas. The contribution of shrubs to total richness increased with increasing elevation whereas that of trees and lianas decreased.
Plant species distributions show patterns along elevation gradients. Regardless of the diverse Afromontane vegetation in Ethiopia(AFE), studies of elevation patterns of woody plants are limited and they are restricted to small areas or single/few Mountains. Moreover, there is no general consensus on the patterns of woody taxa distribution by elevation. The objectives of this study were to examine the elevation patterns of woody taxa richness and their relationship with elevation in the AFE. Data were collected and compiled from the Flora of Ethiopia and Eritrea(Vols. 1–7). About 5918 plant species of 243 families were examined and their elevational distributions were recorded. The distributional ranges of woody taxa were aggregated at 19 points(sites) at 100 m intervals starting from 1500 to 3400 m a.s.l. Single-factor analysis of variance(one-way ANOVA) was used to test the hypothesis that mean species richness of woody taxa decreases from the lower to the upper limit of AFE. Simple linear correlation and regression were used to show the relationships of woody taxa richness with elevation. We documented the presence of 505 woody taxa(441 species,31 subspecies and 33 varieties) representing 267 genera and 90 families in the AFE. In terms of habit, 279 taxa are shrubs, 178 are trees and 48 are lianas. The distribution of woody taxa(trees, shrubs and lianas) showed a slight increase at the lower portion and a monotonic decline with increasing elevation. Species richness of trees, shrubs and lianas was negatively and significantly correlated with elevation(r =-0.985,-0.984,-0.981, respectively; all p <0.001). Our hypothesis was accepted because mean richness significantly decreased from the lower to the upper limit of AFE(p <0.001). Generally, monotonic patterns of decline in richness were observed for trees, shrubs and lianas. The contribution of shrubs to total richness increased with increasing elevation whereas that of trees and lianas decreased.
引文
Austin MP(1980)Searching for a model for use in vegetation analysis.Vegetatio 42(1):11-21.doi:10.1007/BF00048865
Aynekulu E(2011)Forest diversity in fragmented landscapes o northern Ethiopia and implications for conservation.Ph.DDissertation University of Bonn,Bonn,pp 1-132
Barry RG(2008)Mountain weather and climate.Cambridge Univer sity,Cambridge,pp 1-506
Bekele T(1993)Vegetation ecology of remnant Afromontane forest on the central plateau of Shewa,Ethiopia.Ph.D.Dissertation Uppsala University,Uppsala,pp 1-64
Berhanu A(2015)Endemic plant taxa within the Afromontan vegetation in Ethiopia:implications for plant biodiversity conservation.Addis Ababa University,Addis Ababa,pp 1-22
Brown JH,Lomolino MV(1998)Biogeography(2nd edn).Courie Companies,Sunderland,pp 1-704
Cox CB,Moore PD(2005)Biogeography:an ecological and evolutionary approach,7th edn.Blackwell,Oxford,pp 1-440
Demissew S,Friis I(2009)Natural vegetation of the Flora Area.In Hedberg I,Friis I,Persson E(eds)Flora of Ethiopia and Eritre vol 8.General part and index to vols 1-7.The Nationa Herbarium,Addis Ababa and Uppsala,pp 27-32
Denu D(2006)Floristic composition and ecological study of Bibit forest(Gura Ferda),southwest Ethiopia.MSc.Thesis,Addi Ababa University,Addis Ababa,pp 1-83
Edwards S,Tadesse M,Hedberg I(eds)(1995)Flora of Ethiopia and Eritrea.Cannelaceae to Euphorbiaceae,vols 2-2.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-456
Edwards S,Demissew S,Hedberg I(eds)(1997)Flora of Ethiopia and Eritrea.Hydrocharitaceae to Arecaceae,vol 6.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-586
Edwards S,Demissew S,Tadesse M,Hedberg I(eds)(2000)Flora o Ethiopia and Eritrea.Magnoliaceae to Flacourtiaceae,vols 2-1The National Herbarium,Addis Ababa and Uppsala,pp 1-532
Friis I(1986)The forest vegetation of Ethiopia.Acta Universitati Upsaliensis Symbolae Botanicae Upsaliensis XXVI:31-47
Friis I(1992)Forests and forest trees of northeast tropical Africa Kew Bull Addit Ser 15:1-396
Friis I,Demissew S,Breugel PV(2010)Atlas of the potentia vegetation of Ethiopia.The Royal Danish Academy of Science and Letters,Natural habitats,pp 1-307
Gentry AH(1988)Changes in plant community diversity and floristi composition on environmental and geographical gradients.Ann Mo Bot Gard 75(1):1-34
Gonza′lez AS,Lopez-Mata L(2005)Plant species richness and diversity along an altitudinal gradient in the Sierra Nevada Mexico.Divers Distrib 11(6):567-575
Grytnes JA,Vetaas OR(2002)Species richness and altitude:comparison between null models and interpolated plant specie richness along the Himalayan altitudinal gradient,Nepal.Am Nat 159(3):294-304
Hedberg I(2009)The Ethiopian flora project-an overview.In Hedberg I,Friis IB,Persson E(eds)Flora of Ethiopia and Eritrea,vol 8.The National Herbarium,Addis Ababa and Uppsala,pp 1-331
Hedberg I,Edwards S(eds)(1989)Flora of Ethiopia and Eritre Pittosporaceae to Araliaceae,vol 3.The National Herbarium Addis Ababa and Uppsala,pp 1-659
Hedberg I,Edwards S,Nemomissa S(eds)(2003)Flora of Ethiopi and Eritrea.Apiaceae to Dipsacaceae vols 4-1.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-352
Hedberg I,Friis I,Edwards S(eds)(2004)Flora of Ethiopia and Eritrea.Asteraceae(Compositae),vols 4-2.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-408
Hedberg I,Kelbessa E,Edwards S,Demissew S,Persson E(eds(2006)Flora of Ethiopia and Eritrea.Gentianaceae to Cyclo cheilaceae,vol 5.The National Herbarium,Addis Ababa and Uppsala,pp 1-690
Hedberg I,Friis I,Persson E.(eds)(2009)Flora of Ethiopia and Eritrea vol 8.General part and index to Vols 1-7.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-331
Henrik BH,Jon M,Risto V,John-Arvid G,Lauri O,Anders A(2006Effects of altitude and topography on species richness o vascular plants,bryophytes and lichens in alpine communities J Veg Sci 17:37-46
Jime′nez-Castillo M,Wiser SK,Lusk C(2006)Elevational parallels o latitudinal variation in the proportion of lianas in woody floras J Biogeogr 34(1):163-168
Kebede M,Yirdaw E,Luukkanen O,Lemenih M(2013)Plant community analysis and effect of environmental factors on the diversity of woody species in the moist Afromontane forest of Wondo Genet,south central Ethiopia.Biodiv Res Conserv 29:63-80
Kharkwal G,Mehrotra P,Rawat YS,Pangtey YPS(2007)Phytodi versity and growth form in relation to altitudinal gradient in th central Himalayan(Kumaun)region of India.Curr Sc89(5):873-878
Lomolino MV(2001)Elevation gradients of species-density:histor ical and prospective views.Glob Ecol Biogeogr 10:3-13
Mc Cain CM(2007)Could temperature and water availability driv elevational species richness patterns?A global case study fo bats.Glob Ecol Biogeogr 16:1-13
Mc Cain CM,Grytnes JA(2010)Elevational gradients in specie richness.In:Encyclopedia of life sciences(ELS).Wiley Chichester.doi:10.1002/9780470015902
Pinokiyo A,Singh KP,Singh JS(2008)Diversity and distribution o Lichens in relation to altitude within a protected biodiversity ho spot,north-east India.Lichenologist 40(1):47-62
Rahbek C(2005)The role of spatial scale and the perception of large scale species-richness patterns.Ecol Lett 8:224-239
Ren H,Niu S,Zhang L,Ma K(2007)Distribution of vascular plan species richness along an elevational gradient in the Dongling Mountains,Beijing,China.J Integr Plant Biol 48(2):153-160
Rowe RJ,Lidgard S(2008)Elevational gradients and specie richness:do methods change pattern perception.Glob Eco Biogeogr 18:163-177
Rutten G,Ensslin A,Hemp A,Fischer M(2015)Vertical and horizontal vegetation structure across natural and modified habitat types at Mount Kilimanjaro.PLo S ONE 10(9):1-15
Sanders NJ,Rahbek S(2012)The patterns and causes of elevationa diversity gradients.Ecography 35:1-3.doi:10.1111/j.1600-05872011.07338.x
Sanders NJ,Moss J,Wagner D(2003)Patterns of ant species richnes along elevational gradients in an arid ecosystem.Glob Eco Biogeogr 12:93-102
Schmitt CB,Denich M,Demissew S,Friis I,Boehmer HJ(2009Floristic diversity in fragmented Afromontane rainforests:alti tudinal variation and conservation importance.Appl Veg Sc13:291-304
Sharma CM,Suyal S,Gairola S,Ghildiyal SK(2009)Specie richness and diversity along an altitudinal gradient in mois temperate forest of Garhwal Himalaya.J Am Sci 5(5):119-128
Shimono A,Zhou H,Shen H,Hirota M,Ohtsuka T,Tang Y(2010Patterns of plant diversity at high altitudes on the Qinghai Tibetan Plateau.J Plant Ecol 3(1):1-7
R Core Team(2015)R:a language and environment for statistica computing.R Foundation for Statistical Computing,Vienna http://www.R-project.org
Teketay D,Bekele T(1995)Floristic composition of Wof-Wash natural forest,central Ethiopia:implications for the conservation of biodiversity.Feddes Repert 106:127-147
Toledo-Garibaldi M,Williams-Linera G(2014)Tree diversity patterns in successive vegetation types along an elevation gradient in the mountains of eastern Mexico.Ecol Re29(6):1097-1104
Tu W,Gao X,Wu N,Liu S(2010)Altitudinal patterns of vascula plant richness in high mountains:applying of generative additiv model.Pol J Ecol 58(2):231-240
Wana D(2009)Plant species and functional diversity along altitudinal gradients,southwest Ethiopian highlands.Ph.DDissertation,Bayreuth University,Bayreuth,pp 1-139
Woldu Z(1999)Forests in the vegetation types of Ethiopia and thei status in the geographical context.In:Edwards S,Demissie ABekele T,Haase G(eds)Forest genetic resources conservation principles,strategies and actions.Proceedings of the nationa forest genetic resources conservation strategy developmen workshop.Institute of Biodiversity Conservation and Research Addis Ababa,pp 1-38
Yoda K(1967)A preliminary survey of the forest vegetation o eastern Nepal.II.General description,structure and floristi composition of sample plots chosen from different vegetation zones.J Coll Arts Sci 5:99-140
Yu H,Saprunoff M(2012)Distribution of plant species richnes along elevation gradient in Hubei Province,China.Internationa Institute for Earth System Science,Nanjing University,Nanjing pp 378-386
Aynekulu E(2011)Forest diversity in fragmented landscapes o northern Ethiopia and implications for conservation.Ph.DDissertation University of Bonn,Bonn,pp 1-132
Barry RG(2008)Mountain weather and climate.Cambridge Univer sity,Cambridge,pp 1-506
Bekele T(1993)Vegetation ecology of remnant Afromontane forest on the central plateau of Shewa,Ethiopia.Ph.D.Dissertation Uppsala University,Uppsala,pp 1-64
Berhanu A(2015)Endemic plant taxa within the Afromontan vegetation in Ethiopia:implications for plant biodiversity conservation.Addis Ababa University,Addis Ababa,pp 1-22
Brown JH,Lomolino MV(1998)Biogeography(2nd edn).Courie Companies,Sunderland,pp 1-704
Cox CB,Moore PD(2005)Biogeography:an ecological and evolutionary approach,7th edn.Blackwell,Oxford,pp 1-440
Demissew S,Friis I(2009)Natural vegetation of the Flora Area.In Hedberg I,Friis I,Persson E(eds)Flora of Ethiopia and Eritre vol 8.General part and index to vols 1-7.The Nationa Herbarium,Addis Ababa and Uppsala,pp 27-32
Denu D(2006)Floristic composition and ecological study of Bibit forest(Gura Ferda),southwest Ethiopia.MSc.Thesis,Addi Ababa University,Addis Ababa,pp 1-83
Edwards S,Tadesse M,Hedberg I(eds)(1995)Flora of Ethiopia and Eritrea.Cannelaceae to Euphorbiaceae,vols 2-2.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-456
Edwards S,Demissew S,Hedberg I(eds)(1997)Flora of Ethiopia and Eritrea.Hydrocharitaceae to Arecaceae,vol 6.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-586
Edwards S,Demissew S,Tadesse M,Hedberg I(eds)(2000)Flora o Ethiopia and Eritrea.Magnoliaceae to Flacourtiaceae,vols 2-1The National Herbarium,Addis Ababa and Uppsala,pp 1-532
Friis I(1986)The forest vegetation of Ethiopia.Acta Universitati Upsaliensis Symbolae Botanicae Upsaliensis XXVI:31-47
Friis I(1992)Forests and forest trees of northeast tropical Africa Kew Bull Addit Ser 15:1-396
Friis I,Demissew S,Breugel PV(2010)Atlas of the potentia vegetation of Ethiopia.The Royal Danish Academy of Science and Letters,Natural habitats,pp 1-307
Gentry AH(1988)Changes in plant community diversity and floristi composition on environmental and geographical gradients.Ann Mo Bot Gard 75(1):1-34
Gonza′lez AS,Lopez-Mata L(2005)Plant species richness and diversity along an altitudinal gradient in the Sierra Nevada Mexico.Divers Distrib 11(6):567-575
Grytnes JA,Vetaas OR(2002)Species richness and altitude:comparison between null models and interpolated plant specie richness along the Himalayan altitudinal gradient,Nepal.Am Nat 159(3):294-304
Hedberg I(2009)The Ethiopian flora project-an overview.In Hedberg I,Friis IB,Persson E(eds)Flora of Ethiopia and Eritrea,vol 8.The National Herbarium,Addis Ababa and Uppsala,pp 1-331
Hedberg I,Edwards S(eds)(1989)Flora of Ethiopia and Eritre Pittosporaceae to Araliaceae,vol 3.The National Herbarium Addis Ababa and Uppsala,pp 1-659
Hedberg I,Edwards S,Nemomissa S(eds)(2003)Flora of Ethiopi and Eritrea.Apiaceae to Dipsacaceae vols 4-1.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-352
Hedberg I,Friis I,Edwards S(eds)(2004)Flora of Ethiopia and Eritrea.Asteraceae(Compositae),vols 4-2.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-408
Hedberg I,Kelbessa E,Edwards S,Demissew S,Persson E(eds(2006)Flora of Ethiopia and Eritrea.Gentianaceae to Cyclo cheilaceae,vol 5.The National Herbarium,Addis Ababa and Uppsala,pp 1-690
Hedberg I,Friis I,Persson E.(eds)(2009)Flora of Ethiopia and Eritrea vol 8.General part and index to Vols 1-7.The Nationa Herbarium,Addis Ababa and Uppsala,pp 1-331
Henrik BH,Jon M,Risto V,John-Arvid G,Lauri O,Anders A(2006Effects of altitude and topography on species richness o vascular plants,bryophytes and lichens in alpine communities J Veg Sci 17:37-46
Jime′nez-Castillo M,Wiser SK,Lusk C(2006)Elevational parallels o latitudinal variation in the proportion of lianas in woody floras J Biogeogr 34(1):163-168
Kebede M,Yirdaw E,Luukkanen O,Lemenih M(2013)Plant community analysis and effect of environmental factors on the diversity of woody species in the moist Afromontane forest of Wondo Genet,south central Ethiopia.Biodiv Res Conserv 29:63-80
Kharkwal G,Mehrotra P,Rawat YS,Pangtey YPS(2007)Phytodi versity and growth form in relation to altitudinal gradient in th central Himalayan(Kumaun)region of India.Curr Sc89(5):873-878
Lomolino MV(2001)Elevation gradients of species-density:histor ical and prospective views.Glob Ecol Biogeogr 10:3-13
Mc Cain CM(2007)Could temperature and water availability driv elevational species richness patterns?A global case study fo bats.Glob Ecol Biogeogr 16:1-13
Mc Cain CM,Grytnes JA(2010)Elevational gradients in specie richness.In:Encyclopedia of life sciences(ELS).Wiley Chichester.doi:10.1002/9780470015902
Pinokiyo A,Singh KP,Singh JS(2008)Diversity and distribution o Lichens in relation to altitude within a protected biodiversity ho spot,north-east India.Lichenologist 40(1):47-62
Rahbek C(2005)The role of spatial scale and the perception of large scale species-richness patterns.Ecol Lett 8:224-239
Ren H,Niu S,Zhang L,Ma K(2007)Distribution of vascular plan species richness along an elevational gradient in the Dongling Mountains,Beijing,China.J Integr Plant Biol 48(2):153-160
Rowe RJ,Lidgard S(2008)Elevational gradients and specie richness:do methods change pattern perception.Glob Eco Biogeogr 18:163-177
Rutten G,Ensslin A,Hemp A,Fischer M(2015)Vertical and horizontal vegetation structure across natural and modified habitat types at Mount Kilimanjaro.PLo S ONE 10(9):1-15
Sanders NJ,Rahbek S(2012)The patterns and causes of elevationa diversity gradients.Ecography 35:1-3.doi:10.1111/j.1600-05872011.07338.x
Sanders NJ,Moss J,Wagner D(2003)Patterns of ant species richnes along elevational gradients in an arid ecosystem.Glob Eco Biogeogr 12:93-102
Schmitt CB,Denich M,Demissew S,Friis I,Boehmer HJ(2009Floristic diversity in fragmented Afromontane rainforests:alti tudinal variation and conservation importance.Appl Veg Sc13:291-304
Sharma CM,Suyal S,Gairola S,Ghildiyal SK(2009)Specie richness and diversity along an altitudinal gradient in mois temperate forest of Garhwal Himalaya.J Am Sci 5(5):119-128
Shimono A,Zhou H,Shen H,Hirota M,Ohtsuka T,Tang Y(2010Patterns of plant diversity at high altitudes on the Qinghai Tibetan Plateau.J Plant Ecol 3(1):1-7
R Core Team(2015)R:a language and environment for statistica computing.R Foundation for Statistical Computing,Vienna http://www.R-project.org
Teketay D,Bekele T(1995)Floristic composition of Wof-Wash natural forest,central Ethiopia:implications for the conservation of biodiversity.Feddes Repert 106:127-147
Toledo-Garibaldi M,Williams-Linera G(2014)Tree diversity patterns in successive vegetation types along an elevation gradient in the mountains of eastern Mexico.Ecol Re29(6):1097-1104
Tu W,Gao X,Wu N,Liu S(2010)Altitudinal patterns of vascula plant richness in high mountains:applying of generative additiv model.Pol J Ecol 58(2):231-240
Wana D(2009)Plant species and functional diversity along altitudinal gradients,southwest Ethiopian highlands.Ph.DDissertation,Bayreuth University,Bayreuth,pp 1-139
Woldu Z(1999)Forests in the vegetation types of Ethiopia and thei status in the geographical context.In:Edwards S,Demissie ABekele T,Haase G(eds)Forest genetic resources conservation principles,strategies and actions.Proceedings of the nationa forest genetic resources conservation strategy developmen workshop.Institute of Biodiversity Conservation and Research Addis Ababa,pp 1-38
Yoda K(1967)A preliminary survey of the forest vegetation o eastern Nepal.II.General description,structure and floristi composition of sample plots chosen from different vegetation zones.J Coll Arts Sci 5:99-140
Yu H,Saprunoff M(2012)Distribution of plant species richnes along elevation gradient in Hubei Province,China.Internationa Institute for Earth System Science,Nanjing University,Nanjing pp 378-386