Assessment Reveals Urgency To Defend Tanzania’s Forests
Several isolated patches of mountain forests support some of Tanzania’s most species-rich areas of extreme conservation concern. The Eastern Arc Mountains is a chain of 13 separate blocks formed on crystalline bedrock that contain some of the highest densities of endemic plant and animal species in the world.
These forests contain at least 800 endemic vascular plant species. Diverse forests also occur on the volcanic peaks of northern Tanzania, most notably Mt. Kilimanjaro, Mt. Meru, and Ngorongoro. Montane forests also occur near Lake Tanganyika and on the Kitulo Plateau. Moorlands and afromontane grasslands on Mount Kilimanjaro, Mount Meru, and Ngorongoro support giant groundsels, lobelias and a number of Afromontane sunbirds. It is estimated that more than 70 percent of the original extent of the Eastern Arc Forests have been cleared and agriculture encroachment, grazing and fire threatens the remaining forests.
In addition to their importance for biodiversity, montane ecosystems are critical water catchments and most have been designated as catchment forest reserves. Fire and clearing removed about one-third of the forest cover on Kilimanjaro during the past 70 years; loss of these forests is considered a greater threat to sustained stream flow than disappearance of the mountain’s ice cap.
According to the Food and Agriculture Organization (FAO), about 334,280 km2, or about 35 percent, of Tanzania is forested. The FAO estimates that between 1990 and 2010, Tanzania lost an average of about one percent of its forest cover per year, and the rate of deforestation was fairly stable over these two decades. Tanzania will soon complete the country’s first ever comprehensive forest inventory, the National Forest Resources Monitoring and Assessment (NAFORMA) project.
The freshwater ecosystems of Tanzania include rivers and freshwater lakes, including Lake Victoria, Lake Tanganyika, Lake Nyasa, Lake Rukwa and Lake Chala. Saline lakes, Natron, Manyara, and Eyasi, are found in the Rift Valley. The country has nine major river basins.
Tanzania is endowed with a variety of wetland ecosystems, four of which have been designated as Wetlands of International Importance under the Ramsar Convention on Wetlands. Marine and coastal wetlands are typically associated with river deltas. The Rufiji Delta is the most extensive and ecologically important of these. The ecological status and trends of rivers and wetlands in Tanzania was reviewed in the 2011 Strategic Environmental and Social Assessment (SESA) for the National Irrigation Policy and National Irrigation Master Plan. The assessment found that in the past decade or two, the ecological integrity of many river systems and wetlands in Tanzania has decreased, often because the “majority of the irrigation schemes abstract water from seasonal rivers, which are already water stressed.” The assessment concluded that most irrigation schemes were planned without adequate attention to maintaining the level of flows and water levels to conserve sensitive freshwater and wetland habitats and species.
Mangrove forests are found in all coastal districts of Tanzania. Nine species of mangroves are found in mainland Tanzania and Zanzibar. The largest continuous mangrove forests are in the 20 Tanzania Environmental Threats and Opportunities Assessment districts of Rufiji, Kilwa, Tanga-Muheza, and Mtwara. The Rufiji Delta supports the largest mangrove forest in East Africa. It is one of Tanzania’s four Ramsar sites. Like coral reefs, mangrove forests are critical habitats with great ecological and economic value. They are keystone ecosystems because of their high productivity, producing large quantities of organic matter that serve as food for many organisms. This includes species living within the mangrove and also beyond it, since much of the organic matter produced moves to other areas of the marine environment.
Mangroves serve as feeding, breeding, and nursery grounds for a great variety of invertebrates and fish, many of which move out into the ocean during their adult stages. Satellite imagery from 1990 and 2000 shows that there has been a small decrease in the overall area of mangrove coverage. In 2000 the area covered by mangroves was approximately 108,000 ha. Economically, mangroves are a source of firewood, charcoal, building poles, materials for boat construction, tannin, and traditional medicines. “Rufiji Delta has a total of 53,000 ha of mangrove forests, which is equal to 52% of mangrove forests in the country.”
According to the 2003 State of the Coast Report, “during past decades, degradation of mangroves occurred in many parts of the country. Besides a decrease in the area coverage of mangroves, there was also considerable decrease in the density, height and canopy cover of the mangroves within the forests.” Although Tanzania experienced only a small decrease in the overall mangrove coverage between 1990 and 2000, mangrove ecosystems are being altered by uncontrolled human activities, mainly through overexploitation of mangrove wood for construction and fuel, and from cutting of substantial areas of mangroves for solar salt pans, agriculture and aquaculture.
Agriculture is the foundation of the Tanzanian economy. It accounts for about half of the national income, three quarters of merchandise exports, is a source of food, and provides employment to about 80% of Tanzanians. Agriculture in Tanzania is dominated by smallholder farmers cultivating farms of less than three hectares, and is mainly rainfed, not irrigated, agriculture. About 70% of Tanzania’s crop area is cultivated by hand hoe, 20% by ox plough and 10% by tractor.
Food crop production dominates the agriculture economy. Irrigated agriculture in some areas helps to stabilize agricultural production, improve food security, increase farm productivity and income, and produce higher-value crops such as vegetables and flowers. Maize is the country’s main subsistence crop and is grown by more than 50% of Tanzanian farmers and is found in all regions of the country. Most of Tanzania is classified broadly as a ‘Maize-Mixed’ farming system with areas of root crop-based farming in the southern and northwestern areas. Rice is the second most important staple in Tanzania. Rainfed paddy rice production by smallholders is centered in Mbeya, Morogoro, Mwanza, Shinyanga, and Tabora. Other major food crops include sorghum, millet, wheat, pulses, cassava, potatoes, bananas, plantains, sugar, groundnuts, sesame, coconuts, and soybeans. Much of Tanzania’s sorghum and millet are produced in arid and semi-arid agro-ecological zones. Finger millet is popular in the country’s southwestern regions. Tanzanian agriculture can be classified into ten farming systems, which have developed in response to the country’s agro-ecological zones:
- Banana/Coffee/Horticulture system, found in Kagera, Kilimanjaro, Arusha, Kigoma and Mbeya regions; tree crops, intensive land use, volcanic soils with high fertility;
- Maize/Legume system, found in Rukwa, Ruvuma, Arusha, Kagera, Shinyanga, Iringa, Mbeya, Kigoma, Tabora, Tanga, Morogoro, Kahama, Biharamulo; shifting cultivation, maize and legumes, beans and groundnuts intercropped, coffee;
- Cashew/Coconut/Cassava system, found in coast region, eastern Lindi and Mtwara; Rice/Sugarcane system, found in alluvial river valleys;
- Sorghum/Bulrush Millet/Livestock system, found in Sukumaland, Shinyanga and rural Mwanza; sorghum, millet, maize and cotton, oilseeds, rice;
- Tea/Maize/Pyrethrum system, found in Njombe and Mufindi districts in Iringa region; tea, maize, Irish potatoes, beans, wheat, pyrethrum, wattle trees, sunflower;
- Cotton/Maize system, found in Mwanza, Shinyanga, Kagera, Mara, Singida, Tabora and Kigoma, Morogoro, Coast, Mbeya, Tanga, Kilimanjaro, and Arusha;
- Horticulture-based system, found in Lushoto district, Tanga region, Morogoro region, and Iringa rural in Iringa region; vegetables (cabbages, tomatoes, sweet pepper, cauliflower lettuce and indigenous vegetables), fruits, (pears, apples, plums, passion fruit, avocado), maize, coffee, Irish potatoes, tea, beans;
- Wet Rice irrigated system, occupies river valleys and alluvial plains, Kilombero, Wami Valleys, Kilosa, Lower Kilimanjaro, Ulanga, Kyela, Usangu and Rufiji; and
- Pastoralist and Agro-pastoralist system, found in semi-arid areas, Dodoma, Singida, parts of Mara and Arusha, Chunya districts, Mbeya and Igunga district in Tabora; deep attachment to livestock and simple cropping systems.
As a tropical country with a high level of ecosystem diversity, the total number of species found in Tanzania vastly exceeds that of most countries. Because species diversity is correlated with ecosystem productivity, highest levels of species richness are found in montane forests and coral reefs. The flora of Tanzania is extremely diverse, with over 12,700 plant species – a figure comprising more than one-third of the total plant species in Africa.
For birds, the most recent estimate by BirdLife International lists 1,128 species. There are more than 300 species of mammals (with around 100 species of bats, and 100 species of rodents), more than 290 species of reptiles, more than 130 amphibian species, and almost 800 species of freshwater invertebrates. The marine environment has more than 7,805 invertebrate species. The country ranks among the top five African biologically rich countries. Tanzania’s unique biogeography has also endowed it with high levels of endemism – species found only in the country, often within a small range.
There are 661 currently globally threatened species recorded in Tanzania. Of those 661 species, 66 are Critically Endangered, 174 are Endangered, 421 are Vulnerable and 347 are endemic to the country. “Tanzania also possesses important populations of species that are globally endangered and threatened. These include black rhinoceros, wild dog, chimpanzee, African elephant, cheetah and wattled crane.”
Saving endangered and threatened species from extinction requires, among other things, that an adequate Environmental Impact Assessment is conducted for infrastructure development projects, as was illustrated by the sad case of the extinction of the Kihansi Spray Toad (Nectophyrnoides asperginis). This endemic toad was known only from the Kihansi Falls in Tanzania, where it was formerly abundant. The decline of this species was caused by the construction of a dam upstream of the falls in 2000 for the Lower Kihansi Hydropower Project. This removed 90 percent of the water flow, which hugely reduced the volume of spray and altered the vegetation. After 2003 the toad population crashed, and in January 2004 only three toads could be found, with just two males heard calling. There have been no records since then, despite surveys, and the species was formally declared extinct in the wild by the IUCN Red List in 2009. The species survives in small numbers in captivity.
Tanzania’s protected area system is designed to conserve its ecosystems and species. Protected areas include landscapes and seascapes falling in one or several of seven different categories: national parks, forest reserves, game reserves, game controlled areas, wildlife management areas, conservation areas, and the special case of the Ngorongoro Conservation Area (NCA).
There are 12 national parks, 540 forest reserves, 28 game reserves, 38 game-controlled areas, and the NCA. More than 25% of Tanzania’s land area falls within protected areas of some category. Sritharan and Burgess (2011) state that “In Tanzania, 33% of the land surface is already designated as PAs” (Sritharan and Burgess, 2011, p.67). National Parks are managed by the Tanzania National Parks (TANAPA), Forest Reserves are managed by the Forest and Beekeeping Division of the Ministry of Natural Resources and Tourism, Game Reserves and Game Controlled Areas are managed by the Wildlife Division under the Ministry of Natural Resources and Tourism, Ngorongoro Conservation Area is managed by the Ngorongoro Conservation Area Authority (NCAA), and Wildlife Management Areas are co-managed by locally formed Community-Based Organizations and the Wildlife Division.
In addition to its national system of protected areas, Tanzania is a party to several international conventions and participates in other international programs that designate areas for conservation focus. Tanzania ratified the Convention Concerning the Protection of the World Cultural and Natural Heritage in 1977, and currently has four UNESCO World Heritage Sites:
- Ngorongoro Conservation Area (1979) (mixed natural and cultural heritage)
- Serengeti National Park (1981) (natural)
- Selous Game Reserve (1982) (natural)
- Kilimanjaro National Park (1987) (natural)
In addition to these, Gombe National Park, Jozani-Chwaka Bay Conservation Area, and the Eastern Arc Mountain Forests have been submitted for inclusion on the Tentative List. Tanzania also participates in the UNESCO Man and the Biosphere Program, and currently has three MAB Sites: Lake Manyara, Serengeti-Ngorongoro, and East Usambara.
Many large international conservation organizations work in Tanzania, and each has focused its work geographically and/or thematically in one way or another. These conservation foci, or ”priorities,” are based on criteria and strategies that reflect the mission and history of each NGO. Each NGO program is derived from its views of the values and benefits of biodiversity, combined with information from conservation science. All of these NGOs are more and more taking an ecosystem and landscape (or seascape) scale approach in their work. One reason for this is the recognition that habitat loss and degradation is generally the most important threat to biodiversity at all levels, and that species-level conservation is impossible without ecosystem level conservation.
- Conservation biologists recognize five main categories of direct threats to biodiversity:
- Conversion, loss, degradation, and fragmentation of natural habitats;
- Over-harvesting or overexploitation of particular species;
- Invasive non-native species that harm native ecosystems or species; and
- Pollution or contamination that harms natural habitats or species.
Climate change effects that harm natural habitats or species The immediate, proximate causes, and the long-term “root” causes or “drivers” of all of these direct threats generally fall into one of three categories:
- Social causes;
- Political, institutional or governance causes; and
- Economic causes.
Once the causes of the direct threats to biodiversity and the environment have been identified, the actions needed to address, reduce, and/or remove them can be determined.
The Analysis Team outlined several actions to conserve biodiversity in the country. In seeking to understand this view, the Team first reviewed Tanzania’s Fourth National Report to the Convention on Biological Diversity, released in 2009:
- Develop and strengthen sectoral and cross-sectoral institutional co-ordination for harmonization and mainstreaming of biodiversity concerns in planning and management;
- Improve community standard of living through equitable sharing of income generated from the sustainable utilization of biodiversity resources;
- Establish and promote research and development programs with a view to building the capacity to efficiently conserve and sustainable use the biodiversity resources;
- Ensure fragile ecosystems such as dry lands, mountainous and wetland ecosystems have specific and well-tailored development programs;
- Adopt community participation approaches at all levels of planning, development and management of biological diversity;
- Integrate biodiversity conservation in national economic planning;
- Establish Environmental Impact Assessment guidelines for aquatic biodiversity;
- Assess biodiversity base potential in marine and freshwaters of Tanzania to govern exploitation and avoid depletion of stocks;
- Prevent and control illegal fishing practice through inspectorate services/surveillance;
- Improve land use planning in coastal areas;
- Increase attention on environmental impacts in proposed development projects;
- Strengthen the capacity of local communities to administer and manage protected areas;
- Recognize the user rights of local communities and empower them to manage and conserve natural resources.
Actions Necessary from Key Informant Interviews:
- Use Integrated, Harmonized, Multi-Sectoral Approaches 17
- Improve Land Use Planning
- Improve Environmental Impact Assessment
- Control Poaching and Illegal Harvesting
- Broaden Participation and Decentralize NRM
- Prevent Corruption
- Develop Mechanisms to Conserve Ecosystem Services
- Improve Woodfuel Efficiency and Find Alternatives
- Improve Climate Information and Maintain Traditional Coping Mechanisms
- Improve Watershed and Water Management
- Stop Forest Conversion to Agriculture
- Control Beach Tourism Development