eastern arc mountains forests of tanzania - Campaign for the ...

Eastern Arc Mountains Forests of Tanzania
3. Justification for Inscription
3.a Criteria under which inscription is proposed (and
justification for inscription under these criteria)
Criteria (ix) be outstanding examples representing significant on-going ecological and biological
processes in the evolution and development of terrestrial, fresh water, coastal and marine ecosystems
and communities of plants and animals
The Eastern Arc Mountains are important biological refugia, with numerous endemic taxa representing ancient
lineages that have survived millions of years of climatic fluctuations elsewhere on the African continent, as well
as being centres of more recent speciation and radiation. For example, almost all of the world’s African violet
(Saintpaulia) species are restricted to the forests on these mountains.
The 9 sites comprising this serial nomination are globally important as a record of evolution of life on earth,
especially for ancient groups of birds, mammals, reptiles and amphibians having 30 million year old and older
radiations. This has been clearly shown by ongoing DNA analysis at the universities of Copenhagen in Denmark,
and Stellenbosh in South Africa. Such evidence is based on there being at least 40 genera of plants and at least
6 genera of vertebrates that are endemic to the Eastern Arc Mountains.
Further evidence includes: bryophytes on the Eastern Arc having affinities to Madagascar, which has been
isolated from mainland Africa for at least 70 million years; and a shrew in the Udzungwa Mountains having its
nearest relatives in the Congo Basin forests, separated for at least 10 million years. The African tailor bird is the
only African member of an Asian bird family and the endemic Udzungwa Partridge has its closest relatives in
Asia. Similar biogeographical disjunctions across large distances around the world are also known in the
invertebrates, for example in the dragonflies. This information and some further examples of evolutionary and
biogeographical processes are summarized in Table 3.
Many of the restricted range species that are found within the Eastern Arc Mountains occur in only a few
localities, or are found throughout much of the Arc, but have extremely narrow altitudinal range (Lovett et al.
2001; Hall et al. 2009). The endemism comprises both newly evolved species and ancient relicts that have their
origins in prehistoric times when a continuous swathe of forest was present across the whole of tropical Africa
(Burgess et al. 2004). This unique biogeography of the Eastern Arc Mountains, and its disjunct nature in patches
that are elevated above the surrounding landscape, give patterns in species distributions and range that are
more similar to true islands than to a mainland region, causing it to be dubbed as 'The Galapagos of Africa' 5 .
New species and genera continue to be discovered, for example a new genus of partridge Xenoperdix in 1991
(Dinesen et al. 1994) and a new genus of mangabey Rungwecebus in 2005 (Jones et al. 2005; Davenport et al.
2006), the first new genus of monkey to be described since 1923 6 . Another notable recent find includes a new
species of giant elephant-shrew Rhynchocyon udzungwensis in 2005 (Rovero et al. 2008), as well as two new
species of African Violet described in 2009 7 . All eight recognised species of African Violets (Saintpaulia spp.) are
found in the Eastern Arc Mountains.
5 E.g. http://www.africarainforest.org/article_galapagos.html Accessed January 2010.
6 Than, Ker (May 11, 2006). "Scientists Discover New Monkey Genus In Africa". LiveScience website
http://www.livescience.com/animals/060511_monkey_genus.html. Accessed January 2010.
7 Haston, E. M. (2009). Saintpaulia ulugurensis. Curtis’s Botanical Magazine 26(3): 270–276; Haston, E. M. (2009). Saintpaulia
watkinsii. Curtis’s Botanical Magazine 26(3): 277–281.
Ministry of Natural Resources and Tourism 62