Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

Mapping High-Altitude Vegetation in the Bale Mountains, Ethiopia
Lucy A. Tallents* and David W. Macdonald
Wildlife Conservation Research Unit, University of Oxford, Tubney House, Abingdon Road,
Tubney, Abingdon, Oxon, Ox13 5qL, UK.
*Email: lucy.tallents@linacre.oxon.org
Abstract
We used remotely-sensed multi-spectral imagery to develop a map of Afroalpine vegetation in the
Bale Mountains in southern Ethiopia. This is the largest and most intact area of Afroalpine vegetation
over 3000 m a.s.l., and harbours many endemic flora and fauna, including several Bale endemics
and the largest population of the rarest canid in the world, the Ethiopian wolf Canis simensis.
We isolated 23 spectrally separable land cover classes using unsupervised classification.
Quantitative vegetation surveys provide descriptions of each class. All classes for which sufficient
ground-truthing data existed (n = 17) were statistically distinct in terms of substrate, species
composition, height and/or vegetation cover. The majority of classes identified discrete vegetation
communities, while some represented the interface of different land cover types which occurred in
the same pixel.
The map provides a comprehensive baseline from which to monitor the effects of
anthropogenic activities and global warming on the extent and degradation of alpine vegetation in
the Bale Mountains, and is a valuable tool for planning natural resource use management within the
Bale Mountains National Park. It also provides the context for research into the habitat preferences
and ecology of the endemic wildlife which the park was established to protect.
Introduction
An understanding of the status and spatial distribution of resources is a prerequisite for effective natural
resource management and integral to the management of both exploited and pristine ecosystems.
As well as enabling the monitoring and assessment of flora, vegetation maps are often the first step
in mapping the distribution of other taxa, and as such are vital tools in cataloguing and managing
biodiversity. Such maps provide baseline data on the current abundance of endangered species and
offer a framework within which to plan ecological research, investigate species interactions, and
assess the response of natural communities to global climate change.
The Bale Mountains are a water catchment (Hillman 1986b) and conservation landscape
(Mittermeier et al. 2005) of international importance. Our aim was to map vegetation in the Afroalpine
zone of the Bale Mountains at a finer spatial scale and broader extent than previously achieved.
<strong>Walia</strong>-<strong>Special</strong> <strong>Edition</strong> on the Bale Mountains 97