The Global Mountain Biodiversity Assessment (GMBA), a part of the DIVERSITAS international programme of biodiversity science, aims to undertake a global assessment of the biological richness of high-elevation biota and to explain the causes of biological richness in mountains as well as changes in this richness over time. Because changes in biodiversity most often result from human land use, assessment of land management consequences is a specific GMBA goal. Upland grazing, often facilitated by fire management, is the most widespread use of mountain terrain and is often followed by erosion and a greater risk to valley and foreland environments. Cultivation of formerly pristine areas and intensification of agriculture in montane areas are often associated with a loss of mountain biodiversity. Both problems are most severe in the tropics and subtropics.
African mountains offer very striking examples of intensification of human pressure on montane areas. Traditionally, in many parts of Africa, humans have settled in mountainous areas, where the climate is mild and the environment relatively disease free compared with arid or very humid lowlands. However, in recent times, increasing population pressure has created an urgent need to find sustainable forms of coexistence of humans and upland biota. This culminates in the question of adequate pasture management in relation to upland cropping and the value of upland forests as a sustainable source of energy and construction wood.
Therefore, an initial GMBA workshop on the theme “Linking Mountain Diversity with Fire, Grazing, and Erosion” was held in cooperation with the African Mountains Association as a part of the 6th International Conference on Sustainable Mountain Development in Africa: agenda for action, from 19 August 2002 to 24 August 2002, in Moshi, Tanzania, at the foot of Mt Kilimanjaro. The aim of the workshop was to collect and consolidate available knowledge on the impacts of land use on mountain biodiversity.
Most of the research presented was on the effects of fire on mountain biodiversity in the tropics and subtropics. Fire has had a serious effect on the diversity of afroalpine vegetation in the Bale Mountains of Ethiopia (M. Fetene), influencing the small-scale vegetation pattern and increasing diversity in the ericaceous belt. But because there is no livestock grazing in the ericaceous belt of any mountains in East Africa, except in Ethiopia, these fires are not truly essential for the subsistence of the local population and should be avoided (K. Wesche). For the Andringitra massif in Madagascar, it appears that fire is the key to preservation of the most precious mountain flora, and a cessation of burning would create a massive loss of species and microhabitats (B. Rasolonandrasana), while also diminishing the value of pastures. Fire is now used as a management tool, involving the local communities in the Andringitra National Park (U. Bloesch). In the Maloti–Drakensberg mountain range between Lesotho and South Africa, one study revealed that species richness was greatest in areas with a biennial spring burn, in contrast to annual burning, and in areas protected from fire (T. Everson). It, therefore, seems that moderate burning regimes often provide sustainable land-use options and at the same time maintain a high level of diversity, with both supporting ecosystem integrity.
A follow-up workshop will be held in La Paz, Bolivia, from 20 August 2003 to 23 August 2003, in the hope of linking experience with mountain research on both continents. Both workshops are supported by the Swiss Agency for Development and Cooperation, FAO, and UNESCO. Results from these symposia and activities will be published and will be inputs for the Convention on Biological Diversity Work Programme on Mountains and Millennium Ecosystem Assessment (Chapter 27 on mountains).
Abstracts of the conference are available online at www.unibas.ch/gmba/moshi.pdf.