Browsing by Author "Stuart, Simon N."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    The biological importance of the Eastern Arc Mountain of Tanzania and Kenya
    (2007-01) Burgess, Neil D.; Butynski, Thomas M.; Cordeiro, Norbert J.; Doggart, Nike; Fjeldså, Jon; Howell, Kim; Kilahama, Felician B.; Loader, Simon; Lovett, Jon C.; Mbilinyi, Boniface P.; Menegon, Michele; Moyer, David; Nashanda, Evarist; Perkin, Andrew; Rovero, Francesco; Stanley, William T.; Stuart, Simon N.
    The Eastern Arc Mountains are renown in Africa for high concentrations of endemic species of animals and plants. Thirteen separate mountain blocks comprise the Eastern Arc, supporting around 3300 km2 of sub-montane, montane and upper montane forest, less than 30% of the estimated original forested area. At least 96 vertebrate species are endemic, split as follows: 10 mammal, 19 bird, 29 reptile and 38 amphibian species. This includes four endemic or nearly endemic species of primate – the Sanje Mangabey, the Iringa Red Colobus, the Mountain Galago and the new Kipunji monkey that forms its own monotypic genus. A further 71 vertebrate species are near-endemic. At least 800 vascular plant species are endemic, almost 10% of these being trees. These endemics include the majority of the species of African violet – Saintpaulia, a well-known flowering plant in Western households. An additional 32 species of bryophytes are also endemic. Many hundreds of invertebrates are also likely to be endemic, with data for butterflies, millipedes and dragonflies indicating potential trends in importance. Seventy-one of the endemic or near-endemic vertebrates are threatened by extinction (8 critical, 27 endangered, 36 vulnerable), with an additional seven wide ranging threatened species. Hundreds of plant species are also threatened. Most Eastern Arc endemics are closed-forest specialists and comprise taxa with an ancient history and those of more recent origin, including some possessing ancient affinities with taxa from West Africa, Madagascar, and even South America and Southeast Asia. Mountain block prioritisation for biodiversity conservation shows that Udzungwas, East Usambaras and Ulugurus are the most important blocks, with other important blocks being the Ngurus and West Usambaras. Rankings are correlated closely with the area of remaining forest. Most of the remaining forest is found within nearly 150 Government Forest Reserves, with 106 of these managed nationally for water catchment, biodiversity and soil conservation and where forest exploitation is not allowed. Outside these areas most forest has been cleared, except in small village burial/sacred sites, a few Village Forest Reserves, and inaccessible areas. In most Eastern Arc Mountains the local populations have not encroached beyond the reserve boundaries to develop farms, but forest resources within the boundaries are used for fuel and building materials and some forests are heavily degraded. Fire is also a problem as it enters and destroys forests during the dry seasons. The future of the biodiversity on the Eastern Arc Mountains is closely tied to management policies and capacity of the Tanzania Forestry and Beekeeping Division, Tanzania National Parks Authority, and Kenya Forest Department. Supporting these agencies in their mandated job is an essential conservation investment over the longer term.
  • Thumbnail Image
    Item
    Confronting Amphibian Declines and Extinctions
    (2006-07) Mendelson, Joseph R.; Lips, Karen R.; Ronald, Gagliardo W.; Rabb, George B.; Collins, James P.; Diffendorfer, James E.; Daszak, Peter; Ibanez, Roberto D.; Zippel, Kevin; Lawson, Dwight; Wright, Kevin M.; Stuart, Simon N.; Gascon, Claude; Da Silva, Helio R.; Burrowes, Patricia A.; Joglar, Rafael L.; La Marca, Enrique; Lotters, Stefan; Du Preez, Louis; Weldon, Ché; Hyatt, Alex D.; Mahecha, J.V. R.; Hunt, Susan; Robertson, Helen; Lock, Brad; Raxworthy, Christopher J.; Frost, Darrel; Lacy, Robert C; Alford, Ross A.; Campbell, Jonathan A.; Olea, Gabriela P.; Bolaños, Federico; Domingo, Jose J. C.; Halliday, Tim; Murphy, James B.; Wake, Marvalee H.; Coloma, Luis A.; Kuzmin, Sergius; Price, Mark S.; Howell, Kim; Lau, Michael W.N.; Pethiyagoda, Rohan; Boone, Michelle; Lannoo, Michael; Blaustein, Andrew R.; Dobson, Andy P.; Griffiths, Richard A.; Crump, Martha L.; Wake, David; Brodie Jr, Edmund D.
    Amphibian declines and extinctions areglobal and rapid: 32.5% of 5743 de-scribed species are threatened, with atleast 9, and perhaps 122, becoming extinct since1980 (1). Species have disappeared across theentire taxonomic group and in nearly all regionsof the planet. These figures are probably under-estimates as entire clades of species are threat-ened. For example, of the 113 species of harle-quin toads (genus Atelopus), 30 are possiblyextinct, and only 10 have stable populations (2).Nearly a quarter of known amphibian specieswere deemed “data-deficient” with respect toconservation status in the recent global assess-ment (1). Losing biodiversity at this taxonomicscale impacts ecosystem goods and services[e.g. (3, 4)]. As amphibian species disappear, wealso lose their untapped potential for advances inbiomedicine and biotechnology in general (5). Losses result from familiar threats (land-usechange, commercial overexploitation, and exoticspecies) and from the emerging infectious dis-ease chytridiomycosis, caused by the fungusBatrachochytrium dendrobatidis (Bd). Pre-dictions are that within 4 to 6 months of Bdarrival at a site where it has not previously beenpresent, ~50% of amphibian species and ~80%of individuals may disappear (6). Global climatechange may be encouraging local conditionsideal for Bd’s persistence and/or spread (7), com-mercial trade of wildlife may also contribute (8),and pollution may increase susceptibility ofspecies to pathogens (9, 10). Traditional pro-grams and current laws and policies alone areinsufficient to address global threats that crossboundaries of reserves and nation
  • Thumbnail Image
    Item
    A methodology for analyzing rare species distribution patterns utilizing GIS technology: The rare birds of Tanzania
    (1989-01) Miller, Ronald I.; Stuart, Simon N.; Howell, Kim
    A simple, straightforward, cartographic modelling technique is presented for measuring relations between environmental characteristics and rare species distribution patterns. This approach is corroborated by digitizing rare bird distribution data for Tanzania and statistically analyzing these patterns in relation to geographic and environmental variables. Of the available natural resource data for Africa, only the vegetation and soils data appeared accurate enough to represent regional natural resource distribution patterns. Available data for Tanzania at the regional scale is not currently precise or comprehensive enough to analyze ongoing dynamic ecological processes. Statistical relations, associated with a study quadrangle within Tanzania, are documented for these parameters. Final confirmation of the accuracy of predictions about rare species diversity patterns will ensue from future field observations. When confirmed, this methodology can be used for setting conservation priorities in biologically little known regions of the world.