DOCSLIB.ORG

Waxing and Waning of Forests: Late Quaternary Biogeography of Southeast Africa

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Waxing and Waning of Forests: Late Quaternary Biogeography of Southeast Africa Received: 12 October 2017 | Revised: 5 March 2018 | Accepted: 9 March 2018 DOI: 10.1111/gcb.14150 PRIMARY RESEARCH ARTICLE Waxing and waning of forests: Late Quaternary biogeography of southeast Africa Sarah J. Ivory1,2 | Anne-Marie Lezine 3 | Annie Vincens4 | Andrew S. Cohen5 1Department of Anthropology, Ohio State University, Columbus, OH, USA Abstract 2Department of Geosciences, Penn State African ecosystems are at great risk. Despite their ecological and economic impor- University, State College, PA, USA tance, long-standing ideas about African forest ecology and biogeography, such as 3LOCEAN, CNRS, Paris, France the timing of changes in forest extent and the importance of disturbance, have been 4CEREGE, CNRS, Aix-en-Provence, France 5Department of Geosciences, University of unable to be tested due to a lack of sufficiently long records. Here, we present the Arizona, Tucson, AZ, USA longest continuous terrestrial record of late Quaternary vegetation from southern Correspondence Africa collected to date from a drill core from Lake Malawi covering the last Sarah J. Ivory, Department of Geosciences, ~600,000 years. Pollen analysis permits us to investigate changes in vegetation Penn State University, State College, PA, USA. structure and composition over multiple climatic transitions. We observe nine Email: [email protected] phases of forest expansion and collapse related to regional hydroclimate change. Funding information The development of desert, steppe and grassland vegetation during arid periods is US National Science Foundation–Earth likely dynamically linked to thresholds in regional hydrology associated with lake System History Program, Grant/Award Number: EAR-0602350; International level and moisture recycling. Species composition of these dryland ecosystems Continental Scientific Drilling Program; varied greatly and is unlike the vegetation found at Malawi today, with assemblages National Science Foundation Graduate Research Fellowship, Grant/Award Number: suggesting strong Somali-Masai affinities. Furthermore, nearly all semiarid 2009078688 assemblages contain low forest taxa abundances, suggesting that moist lowland gal- lery forests formed refugia along waterways during arid times. When the region was wet, forests were species-rich and very high afromontane tree abundances suggest frequent widespread lowland colonization by modern high elevation trees. Further- more, species composition varied little amongst forest phases until ~80 ka when dis- turbance tolerant tree taxa characteristic of the modern vegetation increased in abundance. The waxing and waning of forests has important implications for under- standing the processes that control modern tropical vegetation biogeography as well as the environments of early humans across Africa. Finally, this work highlights the resilience of montane forests during previous warm intervals, which is relevant for future climate change; however, we point to a fundamental shift in disturbance regimes which are crucial for the structure and composition of modern East African landscapes. KEYWORDS Africa, biogeography, global change, hydrology, Lake Malawi, palaeoclimate, palaeoenvironments, tropical forests | Glob Change Biol. 2018;1–13. wileyonlinelibrary.com/journal/gcb © 2018 John Wiley & Sons Ltd 1 2 | IVORY ET AL. 1 | INTRODUCTION emergence of disturbance-maintained Zambezian miombo woodlands, have yet to be resolved due to the availability of sufficiently long Tropical African ecosystems are immensely important for their ecolog- terrestrial records which capture previous warm intervals. Marine ical value, as bastions of biodiversity and endemism, as well as for cores covering this period show a large expansion of afromontane essential resources for millions of people for daily subsistence (e.g. forest, suggesting that ancient forests may have been substantially Doherty, Sitch, Smith, Lewis, & Thornton, 2010; Mittermeier, Turner, different than lowland communities observed today, however, no Larsen, Brooks, & Gascon, 2011; White, 1981). However, African for- terrestrial record has ever documented their presence or extent ests and semiarid lands are already changing as a result of pressure (Dupont et al., 2011; Ning & Dupont, 1997). In addition, palaeocli- from climate and land-use change (Fugere, Kasangaki, & Chapman, mate records from across the continent show strongly antiphased 2016; Newmark & McNeally, 2018; Niang, Ruppel, & Abdrabo, 2014). signals implying that these earlier high amplitude wet–dry cycles of In turn, feedbacks associated with altered disturbance regimes, such as the late Pleistocene occurred asynchronously across the continent. wildfires, on landscapes processes could result in detrimental changes For example at Lake Malawi from ~600 to 100 ka, lake levels to important ecosystems services (e.g. Bond, Woodward, & Midgley, decreased multiple times by as much as À550 m, whereas north of 2005; Midgley & Bond, 2015; Tilman et al., 1997; Van Langevelde the equator, lakes expanded in the Kenyan rift valley (Ivory et al., et al., 2003). Therefore, it is increasingly important to be able to pre- 2016; Salzburger, Van Bocxlaer, & Cohen, 2014; Trauth et al., 2007). dict long-term species responses to climate. However, particularly in These large hydroclimatic shifts and patchiness of continental cli- Africa, modern ecological observations are sparse, and the range of mate likely resulted in massive reorganization of species as they observations is short (e.g. Feeley & Silman, 2011; Willis & Birks, 2006). tracked optimal climate. Perhaps more importantly, although we Furthermore, as tropical climate is likely moving to a state that does know that species respond individualistically to climate (e.g. Palmer not exist today, projecting species’ responses to future change relies et al., 2015; Stewart, 2009), it is yet unclear how ecosystem compo- on extrapolation (Niang et al., 2014; Williams & Jackson, 2007; Wil- sition and structure changed or how differential dispersal may have liams, Jackson, & Kutzbach, 2007). Thus, long-term (>105 year) records influenced community composition and forest succession. which observe the climatic processes that control vegetation structure Lake Malawi, southeast Africa, sits currently at the southern and composition are required (Dietl et al., 2015; Dietl & Flessa, 2017; extent of the Intertropical Convergence Zone (ITCZ) and is sensitive Lindbladh, Fraver, Edvardsson, & Felton, 2013; ). to fluctuations in regional climate (Figure 1; Cohen et al., 2007; Ivory Palaeoecological records have provided insights about long-term et al., 2016; Scholz et al., 2007). Long drill core records from this ecological processes and allowed us to look at vegetation change in lake preserve a regional climate signal over the late Quaternary with response to conditions warmer than today and over periods of rapid rapid transitions from arid to humid climates (Ivory et al., 2016). Fos- change which can be used as future analogues (e.g. Blois, Zarnetske, sil pollen analysis of sediments from this record provides the ideal Fitzpatrick, & Finnegan, 2013; Hughen, Eglinton, Xu, & Makou, opportunity to better understand ecological processes that operate 2004; Salzmann & Hoelzmann, 2005). For example in Africa, the over many climatic transitions. The unique position of the lake with prevalence of forests throughout the region when global tempera- respect to tropical circulation as well as ecologically important tures are higher, such as during interglacials, has been thought of as ecosystems within the African tropics allows us to look at changing canonical, despite some evidence to the contrary (Beuning, Zimmer- forest composition and vegetation structure through time as well man, Ivory, & Cohen, 2011; Ivory, Lezine, Vincens, & Cohen, 2012; alterations to disturbance regimes. Furthermore, this unique record Vincens, Garcin, & Buchet, 2007). Warming and wetting over the last is the first long, terrestrial record of vegetation change from East deglacial period associated with the reinforcement of regional mon- Africa covering the entirety of the late Quaternary (>500 ka) and soons resulted in an expansion of woodlands and forests as well as provides insights into large-scale reorganization of biomes over mul- the retreat of dryland ecosystems, which dominated during the Last tiple wet-dry cycles in African climate. Glacial Maximum (LGM; e.g. Izumi & Lezine, 2016; Maley, 1992). However, hydrological records reconstructed from ancient lake 1.1 | Modern setting deposits and marine cores suggest that LGM to modern climate changes in Africa were small in amplitude and occurred over thou- Lake Malawi, the southernmost lake in the East African Rift System, sands of years with respect to those which occurred earlier in the is composed of a series of alternating N-S oriented half-graben late Pleistocene (Dupont & Kuhlmann, 2017; Dupont et al., 2011; basins (Figure 1). The lake is hydrologically open and is drained by Scholz et al., 2007; Trauth et al., 2007). Thus, as most existing the Shire River to the south (sill depth = 6 m), although most water records do not extend beyond the last glacial period, it is unclear loss occurs via evaporation (Eccles, 1974). Mountain ranges in the whether the LGM-modern vegetation response is indicative of larger northern (Livingstone Mountains and Rungwe Highlands) and the alterations in climate over multiple cycles. However, the lack of long western (Nyika Plateau) watershed rise steeply from the lake shore records has made it challenging
Load more

Recommended publications
  • Phylogeny of a Rapidly Evolving Clade: the Cichlid Fishes of Lake Malawi
    Proc. Natl. Acad. Sci. USA Vol. 96, pp. 5107–5110, April 1999 Evolution Phylogeny of a rapidly evolving clade: The cichlid fishes of Lake Malawi, East Africa (adaptive radiationysexual selectionyspeciationyamplified fragment length polymorphismylineage sorting) R. C. ALBERTSON,J.A.MARKERT,P.D.DANLEY, AND T. D. KOCHER† Department of Zoology and Program in Genetics, University of New Hampshire, Durham, NH 03824 Communicated by John C. Avise, University of Georgia, Athens, GA, March 12, 1999 (received for review December 17, 1998) ABSTRACT Lake Malawi contains a flock of >500 spe- sponsible for speciation, then we expect that sister taxa will cies of cichlid fish that have evolved from a common ancestor frequently differ in color pattern but not morphology. within the last million years. The rapid diversification of this Most attempts to determine the relationships among cichlid group has been attributed to morphological adaptation and to species have used morphological characters, which may be sexual selection, but the relative timing and importance of prone to convergence (8). Molecular sequences normally these mechanisms is not known. A phylogeny of the group provide the independent estimate of phylogeny needed to infer would help identify the role each mechanism has played in the evolutionary mechanisms. The Lake Malawi cichlids, however, evolution of the flock. Previous attempts to reconstruct the are speciating faster than alleles can become fixed within a relationships among these taxa using molecular methods have species (9, 10). The coalescence of mtDNA haplotypes found been frustrated by the persistence of ancestral polymorphisms within populations predates the origin of many species (11). In within species.
    [Show full text]
  • "A Revision of the Freshwater Crabs of Lake Kivu, East Africa."
    Northern Michigan University NMU Commons Journal Articles FacWorks 2011 "A revision of the freshwater crabs of Lake Kivu, East Africa." Neil Cumberlidge Northern Michigan University Kirstin S. Meyer Follow this and additional works at: https://commons.nmu.edu/facwork_journalarticles Part of the Biology Commons Recommended Citation Cumberlidge, Neil and Meyer, Kirstin S., " "A revision of the freshwater crabs of Lake Kivu, East Africa." " (2011). Journal Articles. 30. https://commons.nmu.edu/facwork_journalarticles/30 This Journal Article is brought to you for free and open access by the FacWorks at NMU Commons. It has been accepted for inclusion in Journal Articles by an authorized administrator of NMU Commons. For more information, please contact [email protected],[email protected]. This article was downloaded by: [Cumberlidge, Neil] On: 16 June 2011 Access details: Access Details: [subscription number 938476138] Publisher Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37- 41 Mortimer Street, London W1T 3JH, UK Journal of Natural History Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713192031 The freshwater crabs of Lake Kivu (Crustacea: Decapoda: Brachyura: Potamonautidae) Neil Cumberlidgea; Kirstin S. Meyera a Department of Biology, Northern Michigan University, Marquette, Michigan, USA Online publication date: 08 June 2011 To cite this Article Cumberlidge, Neil and Meyer, Kirstin S.(2011) 'The freshwater crabs of Lake Kivu (Crustacea: Decapoda: Brachyura: Potamonautidae)', Journal of Natural History, 45: 29, 1835 — 1857 To link to this Article: DOI: 10.1080/00222933.2011.562618 URL: http://dx.doi.org/10.1080/00222933.2011.562618 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes.
    [Show full text]
  • Behaviour: an Important Diagnostic Tool for Lake Malawi Cichlids PDF
    FISH and FISHERIES, 2002, 3, 213^224 Behaviour: an important diagnostic tool for Lake Malawi cichlids Jay R Stau¡er Jr1, Kenneth R McKaye2 & Ad F Konings3 1School of Forest Resources, Pennsylvania State University,University Park, Pennsylvania, PA16802, USA; 2Appalachian Laboratory,UMCES,301Braddock Road, Frostburg, Maryland, MD 21532, USA; 3Cichlid Press, PO Box13608, El Paso,Texas, T X 79913, USA Abstract Correspondence: Historically,the cichlid ¢shes of Lake Malawi, which probably represent one of the best Jay R. Stau¡er Jr, examples of rapid radiation of vertebrates, have been diagnosed with morphological School of Forest Resources, and genetic data. Many of the populations once thought to be conspeci¢c have been Pennsylvania State hypothesized to be separate species based on behavioural data. The use of behavioural University, data, as expressed in mate choice based on colour patterns or bower shapes, has been University Park, successfully used to diagnose both rock-dwelling and sand-dwelling cichlid species. Pennsylvania, PA Additionally,a combination of bower shapes and courtship patterns have been used as 16802, USA Tel.: þ1 814 863 0645 synapomorphies to diagnose genera within the Lake Malawi cichlid £ock. It is con- Fax: þ18148653725 cluded that taxonomists need to include behavioural data with morphological and E-mail:[email protected] genetic databases to diagnose species and to determine the phylogenetic relationships withinthis diverse assemblage of ¢shes. Received 5 Dec 2001 Accepted10Jun 2002 Keywords allopatry,behaviour, Cichlidae,
    [Show full text]
  • Continuous 1.3-Million-Year Record of East African Hydroclimate, and Implications for Patterns of Evolution and Biodiversity
    Continuous 1.3-million-year record of East African hydroclimate, and implications for patterns of evolution and biodiversity Robert P. Lyonsa,1, Christopher A. Scholza,2, Andrew S. Cohenb, John W. Kingc, Erik T. Brownd, Sarah J. Ivorye, Thomas C. Johnsond, Alan L. Deinof, Peter N. Reinthalg, Michael M. McGlueh, and Margaret W. Blomeb,3 aDepartment of Earth Sciences, Syracuse University, Syracuse, NY 13244; bDepartment of Geosciences, University of Arizona, Tucson, AZ 85721; cGraduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882; dLarge Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota, Duluth, MN 55812; eInstitute at Brown for the Study of the Environment and Society, Brown University, Providence, RI 02912; fBerkeley Geochronology Center, Berkeley, CA 94709; gDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721; and hDepartment of Earth and Environmental Sciences, University of Kentucky, Lexington, KY 40506 Edited by Mark H. Thiemens, University of California, San Diego, La Jolla, CA, and approved October 29, 2015 (received for review June 30, 2015) The transport of moisture in the tropics is a critical process for the Lake Malawi and Its Catchment global energy budget and on geologic timescales, has markedly Lake Malawi (Nyasa) is one of the world’s largest and oldest lakes, influenced continental landscapes, migratory pathways, and bi- and is situated at the southern end of the East African Rift Sys- ological evolution. Here we present a continuous, first-of-its-kind tem. The hydrologically open, freshwater ecosystem spans 6° of 1.3-My record of continental hydroclimate and lake-level variability latitude (9–15° S), and has a length of ∼580 km and a maximum derived from drill core data from Lake Malawi, East Africa (9–15° S).
    [Show full text]
  • Isotopic Reconstruction of the African Humid Period and Congo Air Boundary Migration at Lake Tana, Ethiopia
    Quaternary Science Reviews 83 (2014) 58e67 Contents lists available at ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia Kassandra Costa a,c,*, James Russell a,*, Bronwen Konecky a,d, Henry Lamb b a Department of Geological Sciences, Brown University, Box 1846, Providence, RI 02912, USA b Institute of Geography and Earth Sciences, University of Wales, Aberystwyth SY23 3DB, UK c Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA d School of Earth & Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0340, USA article info abstract Article history: The African Humid Period of the early to mid-Holocene (12,000e5000 years ago) had dramatic ecological Received 7 June 2013 and societal consequences, including the expansion of vegetation and civilization into the “green Sahara.” Received in revised form While the humid period itself is well documented throughout northern and equatorial Africa, mecha- 9 October 2013 nisms behind observed regional variability in the timing and magnitude of the humid period remain Accepted 28 October 2013 disputed. This paper presents a new hydrogen isotope record from leaf waxes (dD ) in a 15,000-year Available online wax sediment core from Lake Tana, Ethiopia (12N, 37E) to provide insight into the timing, duration, and intensity of the African Humid Period over northeastern Africa. dDwax at Lake Tana ranges between Keywords: À & À & Tropical paleoclimate 80 and 170 , with an abrupt transition from D-enriched to D-depleted waxes between 13,000 e e East Africa 11,500 years before present (13 11.5 ka).
    [Show full text]
  • Rift-Valley-1.Pdf
    R E S O U R C E L I B R A R Y E N C Y C L O P E D I C E N T RY Rift Valley A rift valley is a lowland region that forms where Earth’s tectonic plates move apart, or rift. G R A D E S 6 - 12+ S U B J E C T S Earth Science, Geology, Geography, Physical Geography C O N T E N T S 9 Images For the complete encyclopedic entry with media resources, visit: http://www.nationalgeographic.org/encyclopedia/rift-valley/ A rift valley is a lowland region that forms where Earth’s tectonic plates move apart, or rift. Rift valleys are found both on land and at the bottom of the ocean, where they are created by the process of seafloor spreading. Rift valleys differ from river valleys and glacial valleys in that they are created by tectonic activity and not the process of erosion. Tectonic plates are huge, rocky slabs of Earth's lithosphere—its crust and upper mantle. Tectonic plates are constantly in motion—shifting against each other in fault zones, falling beneath one another in a process called subduction, crashing against one another at convergent plate boundaries, and tearing apart from each other at divergent plate boundaries. Many rift valleys are part of “triple junctions,” a type of divergent boundary where three tectonic plates meet at about 120° angles. Two arms of the triple junction can split to form an entire ocean. The third, “failed rift” or aulacogen, may become a rift valley.
    [Show full text]
  • Fish and Fisheries in Lake Malawi: an Assessment of Four Decades of Management Interventions
    Fish and fisheries in Lake Malawi: an assessment of four decades of management interventions Olaf LF Weyl1, Steve Donda2, Mafaniso Hara3, Friday Njaya2 and Denis Tweddle1 1 South African Institute for Aquatic Biodiversity, South Africa; 2Department of Fisheries, Malawi; 3Institute for Poverty, Land and Agrarian Studies (PLAAS), University of the Western Cape, South Africa African Great Lakes Conference 2–5 May 2017 Entebbe, Uganda Malawi • Population 17 million • 160/182 Human Development Index. • 90% of people are below US$2 a day. • Aid/Government expenditure = 164% • High reliance on natural resources • Natural resource management and agriculture are critical intervention areas. • Fishing important for food security and employment. • Small scale fisheries have been monitored since 1976 >200 species harvested Multi gear fisheries Fisheries value chains 1993 the co-management era begins • 1980s crash of the Chambo fishery in Lake Malombe demonstrated that “top-down management had failed completely”. • 1993 co-management was initiated with FAO, UNDP and GTZ (now GIZ) support on Lake Malombe and then on Lake Malawi. 14000 Others 12000 Kambuzi 10000 Chambo 8000 6000 4000 Total catch (tons) 2000 0 76 78 80 82 84 86 88 90 92 Year “...participatory fisheries management has proven to be the most appropriate method to manage the fish resources in the lakes of Malawi.” (Fisheries Policy 1999) FAO & GIZ interventions Lake Malawi Status 2002 • Decreasing CPUE • Stable yields maintained by increasing effort. • Depletion of high value fish • Chambo fishery decreased from 5000 t/y to 2000 t/y. • Effort reduction recommended. Chambo restoration plan (2005) targets redirection of fishing effort to “under-exploited” offshore stocks.
    [Show full text]
  • NATURALISATION of LAKE MALAWI LEVELS and SHIRE RIVER FLOWS Challenges of Water Resources Research and Sustainable Utilisation of the Lake Malawi- Shire River System
    1st WARFSA/WaterNet Symposium: Sustainable Use of Water Resources, Maputo, 1-2 November 2000 NATURALISATION OF LAKE MALAWI LEVELS AND SHIRE RIVER FLOWS Challenges of Water Resources Research and Sustainable Utilisation of the Lake Malawi- Shire River System Osborne N. SHELA Interconsult (pvt) Limited, Capital City, PO Box 31231, Lilongwe 3, MALAWI 1. Introduction The Lake Malawi and Shire River basin lies in southern part of the Great East African Rift Valley system, which has significantly influenced its shape and morphology. The entire basin area of Lake Malawi/Shire River system is about 150,000 km 2 and is a tributary of Zambezi River. The lake itself has a catchment area of 126,500 km2 square kilometres that is in the territories of Malawi with 87,530 km2, Tanzania with 26,600 km 2 and Mozambique with 12,370 km 2, including the lake surface. Its rift faulting formation has resulted in an unusually low land/lake catchment ratio of 17 to 5 and relatively deep lake with an average depth of about 250 metres and deepest point that is 702 metres below surface. The lake surface is about 28,750 km 2, 590 kilometres long and a maximum width of 80 kilometres, with average observed water level of 474.15 metres a.s.l, as of 1998/99 water-year. It is the eleventh and third largest lake in the world and Africa, respectively. The rift faulting resulted in having tributaries of the lake relatively small compared to the lake itself. The largest tributary is Ruhuhu River in Tanzania with a catchment area of 14,070 km2.
    [Show full text]
  • The 2005 Lake Malawi Scientific Drilling Project
    Palaeogeography, Palaeoclimatology, Palaeoecology 303 (2011) 3–19 Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Scientific drilling in the Great Rift Valley: The 2005 Lake Malawi Scientific Drilling Project — An overview of the past 145,000 years of climate variability in Southern Hemisphere East Africa C.A. Scholz a,⁎, A.S. Cohen b, T.C. Johnson c, J. King d, M.R. Talbot e, E.T. Brown c a Department of Earth Sciences, Syracuse University, Syracuse NY, 13244, USA b Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA c Large Lakes Observatory and Department of Geological Sciences, University of Minnesota Duluth, Duluth, MN 55812, USA d Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA e Department of Earth Science, University of Bergen, N-5007 Bergen, Norway article info abstract Article history: The recovery of detailed and continuous paleoclimate records from the interior of the African continent has Received 18 March 2010 long been of interest for understanding climate dynamics of the tropics, and also for constraining the Received in revised form 17 October 2010 environmental backdrop to the evolution and spread of early Homo sapiens. In 2005 an international team of Accepted 20 October 2010 scientists collected a series of scientific drill cores from Lake Malawi, the first long and continuous, high- Available online 9 November 2010 fidelity records of tropical climate change from interior East Africa. The paleoclimate records, which include lithostratigraphic, geochemical, geophysical and paleobiological observations documented in this special Keywords: 3 Lake Malawi issue of Palaeo , indicate an interval of high-amplitude climate variability between 145,000 and ~60,000 years East African rift ago, when several severe arid intervals reduced Lake Malawi's volume by more than 95%.
    [Show full text]
  • Mediating the Lake Nyasa Border Dispute Between
    MEDIATING THE LAKE NYASA BORDER DISPUTE BETWEEN TANZANIA AND MALAWI AGNES NEEMA KENNETH SUPERVISOR: PROF GILBERT KHADIAGALA A Research Report Submitted to the School of Social Sciences, University of the Witwatersrand, in Partial Fulfilment of the Requirements for the Degree of Master of Arts in the International Relations. 2016 DECLARATION I, Agnes Neema Kenneth, declare that this research report is my own unaided work. It is submitted in fulfilment of the requirements for the degree of Master of Arts in International Relations in the School of Social Sciences, at the University of the Witwatersrand. It has not been submitted before for any degree or examination at the University of the Witwatersrand or any other University. ……………………………… Agnes Neema Kenneth November, 2016 Mediating Border Disputes Page i ABSTRACT The study seeks to examine and provide an understanding of the processes of mediation of a border dispute on Lake Nyasa between Tanzania and Malawi. Border disputes in Africa are sometimes difficult to resolve peacefully and in a sustainable manner. The outcome of adjudication on border issues is normally not predictable, and in most cases, political leaders are not willing to accept the risks of losing their territory. Mediation, which is non-binding arbitration, provides a more flexible and balanced way to reach a satisfactory outcome, but the final results of mediated settlements sometimes makes politicians uncomfortable. This research sketches a conceptual framework of mediation by examining the Lake Nyasa dispute between Tanzania and Malawi. Most of the literature on border conflicts does not adequately address the attempts by African institutions to resolve these conflicts.
    [Show full text]
  • Environmental Assessment of the East African Rift Valley Lakes
    Aquat. Sci. 65 (2003) 254–271 1015-1621/03/030254-18 DOI 10.1007/s00027-003-0638-9 Aquatic Sciences © EAWAG, Dübendorf, 2003 Overview Article Environmental assessment of the East African Rift Valley lakes Eric O. Odada 1, *, Daniel O. Olago 1,Fred Bugenyi 2, Kassim Kulindwa 3,Jerome Karimumuryango 4, Kelly West 5, Micheni Ntiba 6, Shem Wandiga 7,Peninah Aloo-Obudho 8 and Pius Achola 9 1 Department of Geology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya 2 Department of Zoology, Makerere University, P.O. Box 7062, Kampala, Uganda 3 Economics Research Bureau, University of Dar-es-Salaam, P.O. Box 35096, Dar-es-Salaam 4 Director General de L’NECN, Institute National pour L’Environment et la Conservation de la Nature, BP 56, Gitega, Burundi 5 IUCN Eastern Africa Regional Office, P.O. Box 68200, Nairobi, Kenya 6 Department of Zoology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya 7 Kenya National Academy of Sciences, P.O. Box 39450, Nairobi, Kenya 8 Kenyatta University, P.O. Box 43844, Nairobi, Kenya 9 Kenya Red Cross Society, P.O. Box 40712, Nairobi, Kenya Received: 1 October 2002; revised manuscript accepted: 12 June 2003 Abstract. An assessment of the East African Rift Valley ities. Pollution is from uncontrolled discharge of wastes lakes was initiated by the United Nations Environment directly into the lakes. Unsustainable exploitation of fish- Programme (UNEP) with funding from Global Environ- eries and other living resources is caused by over-fishing, ment Facility as part of the Global International Waters destructive fishing practices, and introduction of non-na- Assessment (GIWA).
    [Show full text]
  • A Climatic Context for the Out-Of-Africa Migration
    A climatic context for the out-of-Africa migration Jessica E. Tierney1*, Peter B. deMenocal2, and Paul D. Zander1 1Department of Geosciences, University of Arizona, Tucson, Arizona 85701, USA 2Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA ABSTRACT 45oN Around 200,000 yr ago, Homo sapiens emerged in Africa. By 40 Out of Africa by 50 ka ka, Homo sapiens had spread throughout Eurasia, and a major com- ODP 968 Figure 1. Site map and o te 30 N u Soreq peting species, the Neanderthals, became extinct. The factors that o schematic of geographic R Cave n e r t e u expansion of Homo sapi- drove our species “out of Africa” remain a topic of vigorous debate. h o t r R o rn ens from 200 ka to 50 ka. o N e Existing research invokes climate change as either providing oppor- 15 N th ou RC09-166 Data from this study are tunities or imposing limits on human migration. Yet the paleoclimate S Spread through Africa derived from marine sedi- history of northeast Africa, the gateway to migration, is unknown. 200-90 ka 0o ment core RC09-166. Also Here, we reconstruct temperature and aridity in the Horn of Africa Homo sapiens shown are locations of the region spanning the past 200,000 yr. Our data suggest that warm evolves Ocean Drilling Program o 200-150 ka and wet conditions from 120,000 to 90,000 yr ago could have facili- 15 S (ODP) Site 968 sapropel record and Soreq Cave tated early waves of human migration toward the Levant and Ara- (Israel) δ18O record.
    [Show full text]