tea has been proven to be a highly effective buffer zone around natural highland forests such as the Nyungwe-Kibira forest block. Tea plantations are almost immune to crop raiding, and offer jobs and income to adjacent populations while minimizing agricultural encroachment and human intrusion. Tea is a highland crop which thrives in cool, humid climates – perfect conditions around the Albertine Rift mountain forests. But with increasing concern about climate change issues and rising temperatures, park managers had to start asking themselves whether tea plantations can be practicable buffer zones in future. Will tea leave enough profit in future? Will areas around the forests become more adequate for small-scale farmers’ crops like maize or cassava, which will bring back common human-wildlife conflicts and increase human presence in the forests?
The case is a trigger to start thinking about ecosystem management issues in the face of climate change. One thing is clear: The stable provision of ecosystem services like water, climate regulation, food, fuel, medicines etc. depends on many factors and responds non-linearly to changes. The relation between ecosystem services and climate change is complex. While natural environments support climate regulation through the storage of carbon and atmospheric regulation, their services are also directly affected by climate change:Â perception of biodiversity as some species fail to adapt or migrate and invasive species flourish, freshwater supply, production of wood, fruits and medicinal plants, potential income from tourism. At the same time the regulating services ecosystems provide are crucial for climate change adaptation, particularly in rural African areas. Protection from natural hazards, for example floods and landslides which are likely to increase in future, can be secured by natural forests which help to stabilize slopes and prevent erosion. A good example is the Caribbean island of Hispaniola, shared by Haiti and the Dominican Republic. After a hurricane in 2006, 6000 people died in flash floods and landslides on the Haitian side, where the natural rainforest had been almost entirely cleared for agriculture and charcoal production. On the other side on the border only few people were killed, as the Dominican Republic has an almost intact forest cover which stabilizes the land. Natural forests also help disease control when climate is projected to become warmer and more attractive for insects and pests, and offer sources of alternative income for communities suffering from bad harvests.
Tea Buffer Zone around Nyungwe Forest, Rwanda. Photo: Claudien Nsabagasani, ARCOS
Humans have substantially altered the potential for regulating services by modifying ecosystems and exceeding their capabilities. Forest water sources, for example, are overused throughout the Albertine Rift. Measures we have implemented to maintain benefits from ecosystems and which have been successful in the past and present, might not work out in future. The tea buffer zone is one example, but also local, community-based conservation schemes might have to be altered if changes in supply of ecosystem services occur.
At the moment uncertainty dominates the discussion on climate change and ecosystem services in the Albertine Rift. Climate projections for the regions are mere theories, but they become more advanced. More importantly however, is to understand how the ecosystem services we need are produced and provided by the ecosystems – to identify service providers (species, populations, and habitats) and their functional traits and attributes. How did the variety of biological processes, and functions change over time and how did it respond to environmental changes? What are the synergies and trade-offs in ecosystem services as a result of management practices or environmental change?
See the 22nd issue of the ARCOS newsletter Backbone/Le Pilier coming soon for more discussions on this topic!
