uu.seUppsala University Publications
Change search
Refine search result
12 51 - 68 of 68
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 51.
    Backéus, Ingvar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Tekle, Kebrom
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Experiences from a project on landscape ecology and ecological rehabilitation in Southern Wello, Ethiopia2001In: Sustainable development of dryland areas of East Africa: EC Directorate General XII. Proc. of the Int. Workshop, Addis Ababa 1998, European Commission, Directorate General XII. , 2001, p. 283-289Chapter in book (Refereed)
  • 52.
    Backéus, Ingvar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Zhang, Liquan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    瑞典植物生态学研究简介: An outline of plant ecological researches in Sweden1984In: Acta Phytoecologica Sinica, p. 247-252Article in journal (Refereed)
  • 53.
    Emanuelsson, Urban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Ecological Botany.
    Brukade våtmarker2009In: Europeiska kulturlandskap / [ed] Emanuelsson, Urban, Formas , 2009, p. 274-287Chapter in book (Other (popular science, discussion, etc.))
  • 54.
    Emanuelsson, Urban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Ecological Botany. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Farmed wetlands2009In: The rural landscapes of Europe: how man has shaped European nature / [ed] Urban Emanuelsson, Stockholm: Formas , 2009, p. 277-289Chapter in book (Other (popular science, discussion, etc.))
  • 55.
    Lyaruu, Herbert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Soil seed bank and regeneration potential on eroded hill slopes in the Kondoa Irangi Hills, central Tanzania1999In: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 2, p. 209-214Article in journal (Refereed)
    Abstract [en]

    The soil seed bank of the severely eroded Kondoa Irangi Hills, Tanzania was studied in order to determine the seed density and composition and to establish the relationshiop between seed bank and standing vegetation. The area had not been grazed for 15 yr prior to the study. A recently grazed area was used for comparison. The seed bank density (at 0-5 cm depth) ranged from 344 to 9158 seeds/m2 in the dry season and 172 to 5107 seeds/m2 in the wet season. The seed bank was very heterogeneous, both spatially and temporally, and it showed significant variation in size and composition in both sampling periods. The species similarity between the seed bank and the above-ground vegetation in all plots was low (Sørensen's index = 0.00 – 0.44). The highest similarity was found in the recently grazed area. The seed bank was dominated by annuals and by early successional species. It is concluded that re-vegetating the hill slopes with woody vegetation by using the seed bank will be difficult because seeds of woody species were not found in the soil.

  • 56.
    Lyaruu, Herbert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Eliapenda, Shadrack
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Mwasumbi, Leonard B
    University of Dar es Salaam.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    The Afromontane forest at Mafai in Kondoa Irangi Hills, central Tanzania. A proposal to conserve a threatened ecosystem1997Report (Other academic)
  • 57.
    Lyaruu, Herbert V. M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Eliapenda, Shadrack
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Floristic, structural and seed bank diversity of a dry Afromontane forest at Mafai, central Tanzania2000In: Biodiversity and Conservation, ISSN 0960-3115, E-ISSN 1572-9710, Vol. 9, no 2, p. 241-263Article in journal (Refereed)
    Abstract [en]

    Flora, vegetation and seed bank were studied in a dry Afromontane forest in the Kondoa Irangi Hills, Tanzania with the objective to obtain information necessary for the promotion of conservation of this forest, which is rapidly degenerating due to human pressure. A preliminary checklist of 104 vascular plants occurring in the forest is provided. Based on 27 plots, each of 400 m2, the forest had the following ecological features: mean tree density 408 stems·ha−1; basal area 66.56 m2·ha−1; Shannon and Wiener diversity 2.6406; evenness 0.7585 and species richness 31 tree species per 1.08 ha. The seed bank was dominated by woody species, including mature forest tree species, and had several species in common with the standing vegetation. The forest contains species that are phytogeographically linked to Madagascan, Western and Southern African floras and also species disjunctly distributed in this forest and the Eastern Arc Mountains of Tanzania. Correspondence Analysis of tree species based on size classes showed that the timber species had declining populations, indicating the possibility of genetic erosion, while other species showed expanding or interrupted populations. Some DBH-size classes (e.g. 145.0– 189.9 cm) have disappeared from the forest, presumably due to their selective removal. We recommend detailed integrated floristic and faunistic studies of the forest, targeting the ecologically sensitive indicators of habitat change such as orchids, birds, reptiles and amphibians. Finally, a proposal to conserve the forest under a community-based forest conservation scheme is put forward.

  • 58.
    Mälson, Kalle
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Ecological Botany.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Ecological Botany.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Ecological Botany.
    Long-term effects of drainage and initial effects of hydrological restoration on rich fen vegetation2008In: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 11, no 1, p. 99-106Article in journal (Refereed)
    Abstract [en]

    Questions: What vegetational changes does a boreal rich fen (alkaline fen) undergo during a time period of 24 years after drainage? How is plant species richness affected, and what are the changes in composition of ecological groups of species? Is it possible to recover parts of the original flora by rewetting the rich fen? Which are the initial vegetation changes in the flora after rewetting? What are the major challenges for restoration of rich fen flora after rewetting? Location: Eastern central Sweden, southern boreal vegetational zone. Previously rich fen site, drained for forestry purposes during 1978-1979. The site was hydrologically restored (rewetted) in 2002. Method: Annual vegetation survey in permanent plots during a period of 28 years. Results: There were three successional stages in the vegetational changes. In the first stage there was a rapid (< 5 years) loss of rich fen bryophytes. The second step was an increase of sedges and early successional bryophytes, which was followed by an increase of a few emerging dominants, such as Molinia caerulea, Betula pubescens and Sphagnum spp. After rewetting, there are indications of vegetation recovery, albeit at slow rates. Depending on, for instance, initial species composition different routes of vegetation change were observed in the flora after drainage, although after 24 years, species composition became more homogenous and dominated by a few species with high cover. Conclusion: Major changes have occurred after changes in the hydrology (drainage and rewetting) with a severe impact on the biodiversity among vascular plants and bryophytes. Several rich fen bryophytes respond quickly to the changes in water level (in contrast to vascular plants). The recovery after rewetting towards the original rich fen vegetation is slow, as delayed by substrate degradation, dispersal limitation and presence of dominant species.

  • 59.
    Pettersson, Börge
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre. Växtekologi.
    Krympande torrskogar2001In: Biodiverse, ISSN 1401-5064, Vol. 6, no 4, p. 7-7Article in journal (Other academic)
  • 60.
    Rydin, Håkan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Växtbiologi: nu och för 100 år sedan1998In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 92, p. 1-10Article, review/survey (Other (popular science, discussion, etc.))
  • 61.
    Ssenku, Jamilu Edrisa
    et al.
    Department of Biological Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda.
    Ntale, Muhammad
    Department of Chemistry, College of Natural Sciences, Makerere University, Kampala, Uganda.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. School of Natural Sciences, Technology and Environmental Studies, Södertörns högskola.
    Lehtilä, Kari
    School of Natural Sciences, Technology and Environmental Studies, Södertörns högskola.
    Oryem-Origa, H.
    Department of Biological Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda.
    Dynamics of plant species during phytostabilisation of copper mine tailings and pyrite soils, Western Uganda2014In: Journal of Environmental Engineering & Ecological Science, ISSN 2050-1323, Vol. 3Article in journal (Refereed)
    Abstract [en]

    Introduction: Destruction of vegetation resources emanating from deposition of mine wastes is a serious environmental problem. Conventional plant species restoration methodologies are costly and feasible only on a small scale. The current study was focussed on developing phytostabilisation protocols involving the application of limestone, compost, selected tree species and assessing the re-establishment of plants in polluted soils.

    Methods: Early establishment of plant species under Eucalyptus grandis, Senna siamea and Leucaena leucocephala planted on mine tailings and pyrite soils amended with compost, limestone and limestone+compost was studied. Four plant inventories were conducted on the study plots and surrounding plant communities, involving enumeration of the plant species and estimation of their ground covers. Physico-chemical characteristics of the soils of the study plots were determined each time an inventory was conducted. Data were analysed using R statistical packages vegan and lme4.

    Results: Mine tailings and pyrite soils had extremely low pH, poor nutritional status, low organic matter content and elevated concentrations of heavy metals as compared to the unpolluted soils. Before treatment, species richness, diversity and plant cover were extremely low with most of the ground being completely bare. Treatment of the soils significantly improved the physico-chemical characteristics starting a

    plant succession that increased the number of species from 18 to 215 different species, belonging to 131 genera and 34 families. Plots of the leguminous tree species Senna siamea and Leucaena leucocephala had significantly more species than the non-leguminous Eucalyptus grandis. Early changes in species composition of the restoration plots were minimal. Correspondence analysis (CA) revealed significant differences in species composition between the experimental plots and the plots at the unpolluted site.

    Conclusion: Application of amendment material that significantly alters the physico-chemical characteristics of mine wastes is pre-requisite for their phytostabilisation. Leguminous tree species Senna siamea and Leucaena leucocephala have a higher potential for phytostabilisation of pyrite and copper tailings as their growth led to the establishment of understory plant communities with higher species diversity and cover. 

  • 62.
    Ssenku, Jamilu Edrisa
    et al.
    Department of Plant Sciences, Microbiology and Biotechnology, Makerere University, Kampala, Uganda.
    Ntale, Muhammad
    Department of Chemistry, Makerere University, Kampala, Uganda.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. School of Natural Sciences, Technology and Environmental Studies, Södertörn University College, Huddinge, Sweden.
    Oryem-Origa, Hannington
    Department of Plant Sciences, Microbiology and Biotechnology, Makerere University, Kampala, Uganda.
    Phytoremediation potential of Leucaena leucocephala (Lam.) de Wit. for heavy metal-polluted and heavy metal-degraded environments.2017In: Phytoremediation potential of bioenergy plants / [ed] K. Bauddh, B. Singh & J. Korstad, Springer, 2017, p. 189-209Chapter in book (Other academic)
    Abstract [en]

    Regeneration of heavy metal-polluted and heavy metal-degraded sites has remained a global challenge despite the existence of numerous conventional physico-chemical techniques that can be applied. In view of the large size of the degraded areas and the cost implications, the application of the inexpensive “green” and sustainable technique of phytoremediation is unrivalled by any other possible alternative techniques. However, its effectiveness is largely dependent on judicious selection of the plant to be used. We thus assessed the suitability of Leucaena leucocephala for phytoremediation of heavy metal-polluted and heavy metal-degraded sites. L. leucocephala has numerous inherent characteristics that can be exploited to augment phytoremediation and lower the cost of regenera- tion. The species can survive in harsh environmental conditions with the excep- tion of heavily frosted conditions and occurs in a wide range of ecological settings. The species is fast growing, capable of reaching maturity in 6 to 7 months to produce a vast amount of seeds that can germinate into numerous seedlings to carry on further remediation of the polluted site. It can produce large quantities of phytomass that can accumulate heavy metals and can repeatedly be harvested to regenerate a polluted area through phytoextraction. Heavy metal- laden phytomass of L. leucocephala moulds into furniture and is used for con- struction to preclude contamination at the site of use. It is excellent on coppicing, thus eliminating the costs of replanting during the phytoremediation programme. The species is endowed with high pro ciency for nitrogen xation through nod- ule formation and can substantially revitalize microbial mass and micro- bioactivities to pave way for re-establishment of self-sustaining plant communities over the polluted sites. Its exibility to nodulate with rhizobia of other legumes and its rhizobia to nodulate with other legumes could optimize nitrogen content revitalization of the polluted soils. However, the species is invasive and could be adopted under stringent measures to avoid its spread. It is also very palatable to animals and may thus be of limited application in the phytoremediation of areas accessible to animals. Suitability of the species in heavily polluted areas is mini- mal as many of the inherent characteristics may not fully be expressed. 

  • 63.
    Ssenku, Jamilu
    et al.
    Makerere University.
    Ntale, Muhammed
    Makerere University.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. School of natural sciences, technology and environmental studies, södertörn University.
    Oryem-Origa, Hannington
    Makerere University.
    Assessment of seedling establishment and growth performance of Leucaena leucocephala (Lam.) De Wit., Senna siamea (Lam.) H.S. Irwin & Barneby and Eucalyptus grandis W.Hill ex Maid. in amended and untreated pyrite and copper tailings2014In: Journal of Biosciences and Medicines, ISSN 2327-5081, Vol. 2, p. 33-50Article in journal (Refereed)
    Abstract [en]

    Growth and survival performance of Leucaena leucocephala (Lam.) De Wit., Senna siamea Lam. andEucalyptus grandis W. Hill ex Maid. in amended and untreated pyrite and copper tailings wereevaluated under field conditions. The physico-chemical characteristics of the pyrite soil and tailingswere determined. Growth in height, basal diameter and later dbh, relative growth rate due toheight (RGRh) and basal diameter (RGRd) and survival were determined every after six months. Asplit block experimental design was used and the data collected were analyzed using a statisticalpackage R, with an additional package lme4. Tailings and pyrite soils had extremely low pH, poornutritional status, low organic matter content and elevated concentrations of available heavymetals as compared to the unpolluted soils and treated pyrite soil and copper tailings. Growthperformance was extremely poor on the untreated pyrite soil and copper tailings for all the speciesbut significantly enhanced by the application of compost and limestone. Treatment had a significanteffect on all parameters at all sites. Eucalyptus grandis displayed a higher potential ofphytomass accumulation than Leucaena leucocephala and Senna siamea. Even though Leucaenaleucocephala grew fastest reaching reproductive maturity in 7 months after planting, relative growth rates of the three species were not significantly different at all sites. The three species canbe used for phytostabilisation of the tailings at Kilembe tailings dam sites (KTDS) after treatmentwhile at Low polluted pyrite trail site (LPPTS) and Highly polluted pyrite trail sites (HPPTS) Sennasiamea is more suitable as Eucalyptus grandis and Leucaena leucocephala are susceptible to attacks by Syncerus caffer (Buffalos) and Kobus kob thomasi (Uganda Kob).

  • 64.
    Strömquist, Lennart
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Social and Economic Geography.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Ecological Botany.
    Integrated landscape analyses of change of miombo woodland in Tanzania and its implication for environment and human livelihood2009In: Geografiska Annaler. Series A, Physical Geography, ISSN 0435-3676, E-ISSN 1468-0459, Vol. 91A, no 1, p. 31-45Article in journal (Refereed)
    Abstract [en]

    Landscapes bear witness to past and present natural and societal processes influencing the environment and human livelihoods. By analysing landscape change at different spatial scales over time the effects on the environment and human livelihoods of various external and internal driving forces of change can be studied. This paper presents such an analysis of miombo woodland surrounding the Mkata plains in central Tanzania. The rich natural landscape diversity of the study area in combination with its historical and political development makes it an ideal observation ground for this kind of study. The paper focuses on long-term physical and biological changes, mainly based on satellite information but also on field studies and a review of documents and literature.

    The miombo woodlands are highly dynamic semi-arid ecosystems found on a number of nutrient-poor soil groups. Most of the woodlands are related to an old, low-relief geomorphology of erosion surfaces with relatively deep and leached soils, or to a lesser extent also on escarpments and steep Inselberg slopes with poor soils. Each period in the past has cast its footprints on the landscape development and its potential for a sustainable future use. On a regional level there has been a continual decrease in forest area over time. Expansion of agriculture around planned villages, implemented during the 1970s, in some cases equals the loss of forest area (Mikumi-Ulaya), whilst in other areas (Kitulangalo), the pre-independence loss of woodland was small; the agricultural area was almost the same during the period 1975–1999, despite the fact that forests have been lost at an almost constant rate over the same period. Illegal logging and charcoal production are likely causes because of the proximity to the main highway running through the area. Contrasting to the general regional pattern are the conditions in a traditional village (Ihombwe), with low immigration of people and a maintained knowledge of the resource potential of the forest with regards to edible plants and animals. In this area the local community has control of the forest resources in a Forest Reserve, within which the woody vegetation has increased in spite of an expansion of agriculture on other types of village land. The mapping procedure has shown that factors such as access to transport and lack of local control have caused greater deforestation of certain areas than during the colonial period. Planned villages have furthermore continued to expand over forest areas well after their implementation, rapidly increasing the landscape fragmentation. One possible way to maintain landscape and biodiversity values is by the sustainable use of traditional resources, based on local knowledge of their management as illustrated by the little change observed in the traditionally used area.

  • 65.
    Sundberg, Sebastian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Mälson, Kalle
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Restaurering av dikade rikkärr2011In: Naturvårdskedjan - för en effektiv naturvård / [ed] M. Almstedt Jansson, T. Ebenhard & J. de Jong, Uppsala: Centrum för biologisk mångfald , 2011, p. 252-268Chapter in book (Other academic)
  • 66.
    Sundberg, Sebastian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Stenseke, Marie
    Göteborgs universitet.
    Mälson, Kalle
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Bevarande av våtmarker - hur ska vi göra?2011In: Naturvårdskedjan - för en effektiv naturvård / [ed] M. Almstedt Jansson, T. Ebenhard & J. de Jong, Uppsala: Centrum för biologisk mångfald , 2011, p. 246-251Chapter in book (Other academic)
  • 67.
    Tekle, Kebrom
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Skoglund, Jerry
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Woldu, Zerihun
    Addis Ababa University.
    Vegetation on hill slopes in southern Wello, Ethiopia: Degradation and regeneration1997In: Nordic Journal of Botany, ISSN 0107-055X, E-ISSN 1756-1051, Vol. 17, no 5, p. 483-493Article in journal (Refereed)
    Abstract [en]

    A study was made of the vegetation in southern Wello (Ethiopia) in relation to human impact and the environment. 65 sample plots were laid out and analysed with respect to the cover value of vascular plant species. Altitude, slope, aspect and estimates of grazing pressure for each plot were also recorded along with physical and chemical soil properties analysed for samples taken from each plot. The following environmental factors, isolated by forward selection, show correlation with the axes of Canonical Correspondence Analysis (CCA): altitude, grazing, pH, K, Ca, Mg, slope and aspect.

    Through hierarchical and non-hierarchical clustering methods the vegetation was divided into eight types, from which one was secondary forest characterised by patch dominance of Juniperus procera and Olea europaea ssp. cuspidata. These forest patches are found at high altitude sites and because of their inaccessibility are usually characterised by low livestock density and consequently low grazing pressure. The presence of large boulders and stones in Podocarpus falcatus forest decreases accessibility and creates natural protection for the trees. The other vegetation types, most of which are found at lower altitude and associated with varying intensities of grazing, include grasslands (grazed and protected), regenerating sites dominated by Euclea racemosa and Dodonaea angustifolia, dense and open shrublands and Olea europaea ssp. cuspidata woodlands. Human interference has a major impact on the vegetation of the study area and its recovery will depend on the degree of participation of the local people.

  • 68.
    Woldu, Zerihun
    et al.
    Addis Ababa University.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    The shrubland vegetation in western Shewa, Ethiopia and its possible recovery1991In: Journal of Vegetation Science, ISSN 1100-9233, E-ISSN 1654-1103, Vol. 2, no 2, p. 173-180Article in journal (Refereed)
    Abstract [en]

    Shrubland vegetation and environmental data in western Shewa, Ethiopia have been analysed. Vegetation data include cover-abundance values of vascular plant species; en- vironmental data comprise physical and chemical properties of the soil, altitude, slope, grazing and browsing pressure.

    The vegetation data were subjected to hierarchical and non-hierarchical classification and ordination with correspondence analysis. The classification resulted in seven different vegetation types, ranging from grassland with scattered shrubs to degen- erated forest. Ordination of the data and biplot analysis showed that the vegetation is influenced by anthropogenic factors and altitudinal variation. Sand content is related to a low level of anthropogenic influence whereas silt content is related to a high level. This is explained by historical events rather than by the present situation. Total nitrogen, organic carbon, altitude and slope are positively correlated and these variables are negatively related to anthropogenic influences.

    The shrubland vegetation may have expanded from lower altitudes and drier sites as forests gradually disappeared.

    The recovery of an economically more rewarding vegetation type may be achieved through providing alternative sources of fuel and construction and through prohibiting cultivation and grazing in the shrublands on the hillsides. Regeneration can be accelerated by actively introducing seedlings of tree species that do not need a heavy canopy cover for establishment and growth.

12 51 - 68 of 68
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf