Neil D. Burgess, Paul Harrison, Peter Sumbi, James Laizer, Adam ...

BIODIVERSITY BASELINE: TANZANIA’S COASTAL FORESTS 2011
2 Biodiversity Baseline
2.1 Overview
The Coastal Forests of Eastern Africa epitomize the difficulties of maintaining biodiversity values in the
tropics, in that they show virtually all of the conservation problems faced by conservation planners and
protected area managers. The Coastal Forests are:
Small, and highly fragmented, consisting of many (over 150) separate forest patches, most of
which are less than 500 ha in size, and little protected by government agencies.
Surrounded by impoverished rural communities with a growing demand for farmland and forest
resources.
Individually distinctive, with high local forest endemism and a great array of different plant
communities.
Without the national level `hard' resources such as commercial timber or water catchment, that
would allow species resources to piggyback on their continuation.
The amount of forest remaining in the coastal regions of Tanzania is debated, but the current estimate is
around 358,000 ha (Godoy et al. 2011), declining each year as forest cover is converted to farmland or
heavily cut for timber and charcoal and is changed from forest to bushland or thicket.
2.2 Biological Values of the Coastal Forests
During the past twenty years, the Coastal Forest mosaic of eastern Africa has increasingly become
recognized as an area of major conservation importance on the African continent. White (1983)
described the vegetation of Africa and recognized the Zanzibar-Inhambane Regional Transition Zone
along the eastern seaboard of Africa, and estimated that it possessed ‘at least several hundred’ endemic
plant species. This total was upgraded by Clarke et al. (2000) to at least 1,356 species based on an
examination of botanical literature, allowing the area to be upgraded to a regional centre of plant
endemism (Clarke, 1998). The Coastal Forest habitat mosaic is also recognized as globally important in
analyses of endemic bird species (Stattersfield, 1998) and overall animal and plant species values (WWF)
(Burgess 2004). Twelve Important Bird Areas (IBAs) are recognized in the Coastal Forests of Tanzania
(Baker and Baker 2002).
Today the Coastal Forests of Eastern Africa are recognized as a globally important conservation priority
by BirdLife International, WWF and Conservation International (Stattersfield et al. 1998; Olson and
Dinerstein 1998; Burgess et al. 2004; Mittermeier et al. 2004). In 2002 this Hotspot ranked first among
the Global Hotspots in terms of the number of endemic plant and vertebrate species per unit area and
eighth (globally) in terms of levels of threat (Brooks et al. 2004). The coastal forests are now recognized
as a separate biodiversity hotspot, one of 33 globally, having been divided from the Eastern Arc in the
updated analysis that was published in 2004. Tanzania contains parts of three distinct forest-based
global “hotspots for biodiversity.” 1 These are the Eastern Arc Montane Forests (95% in Tanzania), the