The landscape of Zanzibar has been greatly altered by man over a period of many centuries. Originally, the islands were extensively covered in a variety of forest and woodland types, the Zanzibar Forests described by Greenway (1967) as “one of the most important in eastern and central Africa”, albeit an island archipelago. Unfortunately, very little remains of these great forests, with the main exceptions being the larger, more isolated islands of Pemba and Mafia. Today, Zanzibar’s forests and woodlands are severely fragmented and heavily degraded, with few areas having any form of protection; the total forest cover might be as low as three percent (Jenkins 1997). Although the low lying areas around the coast are swathed in coconut plantations, it is the remnants of the natural forests and the many smallholder farmer’s plots of mixed agroforestry which are of particular interest. Initially, it was the indigenous charcoal producers on the main Zanzibar island who played a large role in deforestation and degradation. Until the mid 20th century, trade in Zanzibar’s forests was largely confined to local use of timber, firewood, and clearing of land for shifting agriculture. However, the turn of the century saw colonial rule and Zanzibar’s integration into the global economy leading to the beginnings of large-scale commercial agriculture. This in turn increased immigration to the islands and greater pressure on the land from a rapidly expanding rural population. During this period, the removal of trees from the islands began to accelerate and has continued to do so until today. This has been engendered by growing demand for timber, as well as the gradual transition to more market-oriented agriculture with the expansion of cloves as a cash-crop for export. The future of Zanzibar’s forests was further complicated by the 1964 revolution and the subsequent formation of an independent nation, as the country struggled with economic instability and changes in governmental policy which greatly influenced land-use and forestry.
Zanzibar, a semi-autonomous group of islands off the coast of Tanzania, has just less than 2000 km2 of land above high water mark. Half of this is occupied by the islands of Unguja (over 1000 km2) and Pemba (just under 500 km2) while the remainder comprises several small islets. The native vegetation of Zanzibar is often said to be derived from a pristine original forest cover although no detailed surveys of the islands were made prior to the impact of extensive human settlement several centuries ago. Today only a few small patches of the found that are demonstrably primary forest remain, for example Ngezi on Pemba and Kiwengwa on Unguja. These areas total less than 2 km2. A preliminary assessment of the vegetation of Zanzibar listed 10 types of primary forest and 6 types of secondary forest, the latter covering a somewhat larger area than the former. Primary forests types comprise afromontane forest on the central hills of Unguja, coral rag forest on fossil coral dunes, a belt of drier forest atop the coral rag and the best known type, the humid and very species-rich East African Coastal Forest, which is now largely restricted to the forest reserves at Jozani on Unguja and Ngezi on Pemba. Secondary forest types are variously derived from clearance of the above. Periods of large scale past land clearance activities, associated with the commercial production of cash crops, give way to abandonment of unproductive farmland and the subsequent natural regeneration and at times planting of native tree species. Forest now covers no more than 5% of the total land area of Zanzibar and this figure is declining. Historical changes in the extent of forests and woodlands have been quantified in large part indirectly, by way of assessments of changes in forest area or aerial extent of specific forest types over time. These studies show that forests were the dominant vegetation of Zanzibar until about 2000 AD. Large scale land clearance for agriculture over the past two centuries and recent economic development have led to one of the highest rates of forest clearance in Tanzania during the period 1950-80. A particularly significant outcome of this time was the onset of a successful campaign by the Department of Forest and beekeeping to quadruple the rate of timber production in order to become self-sufficient in timber and poles. Seven species of tree were prescribed for as the most suitable for these purposes and their prolific logging severely impacted the areas close to villages and the remaining forests on Pemba. Aerial imagery and satellite remote sensing of the 1980s has revealed the extent and impact of current human activity on the island’s vegetation although no data in this respect has yet been obtained for land use changes following the 1980s. The start of the revolutionary war in Mozambique in the late 1970s provided another key stage in the history of Zanzibar’s man-nature interactions. During this period international trade embargoes against Mozambique and regional instability led to a significant rise in the local production of food crops and an increased need for land. This situation was further intensified by an influx of refugees from the Tanzanian mainland. Around 500 acres of forest were cleared annually during the 1980s with the use of tractor and chains from this period up until now. This has continued to the current day in areas such as the South Jozani and Makunduchi forests and several reports indicate that it has been exacerbated by unregulated logging and land speculation during periods of political instability in the mid 1980s to late 1990s. This situation was further intensified by an influx of refugees from the Tanzanian mainland. During recent years, a significant amount of land has been allocated for the production of cloves and there is an increasing trend towards these being grown in monoculture plantations. This is particularly the case on Pemba and is discussed in further detail in relation to threats from agriculture.
The simplest economic value ascribed to a forest resource is the direct extraction of products. Zanzibar’s forests and woodlands have been extensively logged in the past, usually indiscriminately and often with devastating effect. The Chwaka bay area is a good example where large areas of forest, which took thousands of years to develop, were cleared in a few decades and the area now supports a population suffering from extreme land degradation. Logging has also taken place to support the boat building industry. The extensive mangroves around the Zanzibar coastline have provided a cheap source of durable wood for building dhows, Zanzibar’s traditional sailing vessels. Apart from logging, forests have been cleared for cultivation often as a result of population pressure in one area forcing people to find new settlement sites. With Zanzibar’s population doubling every 20 years, it is likely that this trend will continue. In short, the direct extraction of forest products is still occurring in Zanzibar, and in many cases, the resources being extracted are not renewable.
Depth is an inherent feature of a forest, and this is certainly the case with Zanzibar’s forests and woodlands. While there are an infinite number of ways in which to examine this notion of depth, Zanzibar has often examined the value of its forest resources in purely economic terms. The rationale for this is that in a developing country, with a low GNP, it is difficult to justify preservation of a resource on non-economic grounds. It is reasoned that once the economic value of a resource is known, the wise-use options, which will also utilize the resource’s worth for future generations, can be assessed and then implemented. Although this approach tends to be short-sighted given the often unsustainable nature of resource extraction and utilization, the economic value of a forest resource is an important component to consider.
Zanzibar is located in the western Indian Ocean at 6°S and 39°E and is separated from the African continent by a 35 km wide channel. The main island, Unguja (1000 km2), and 50-60 smaller islands make up the Zanzibar Archipelago. Historical records and maps indicate that over the past 150 years, the islands have been subjected to significant environmental change and land use progression. One of the most illustrative examples of this is the islands’ forest cover. At the beginning of the 20th century, the archipelago was heavily forested, and abundant with diverse and unique flora and fauna. Today, however, very little of Zanzibar’s original vegetation cover remains, and the islands have lost an estimated 82% of their native forests and woodlands. Local educational and conservation institutions are very concerned about the future of Zanzibar’s natural resources. They fear that if the islands’ remaining forested areas are not managed effectively, or are left entirely unprotected, the outcome will be disastrous. If current deforestation rates continue, Zanzibar’s forests may be completely depleted within the next 15-20 years (Mgumia, 1997). This would be detrimental to the islands’ terrestrial biodiversity, which is already under threat, and would severely affect the livelihoods of local communities who are dependent on forest products. This paper seeks to identify the major factors and forces responsible for the decline in Zanzibar’s forests and woodlands, and looks at what this situation means for the islands’ environment and the people who inhabit it.
Zanzibar’s forests are the most important area for the conservation of plant biodiversity, with an estimated 25% of plant species being endemic. The remaining 75% are common to the African/Asian mainland. There are almost 1000 species of flowering plants in Zanzibar, with unique species like the “bird’s foot fern”. In the Jozani forest, there are 3 species of syzygium (a traditional food plant), 3 species of costus, and 5 species of ginger. Zanzibar is also known for its spices, and the Chwaka area has one of the last remaining clove trees. Today, the main areas of remaining forest are at Chwaka, Ngezi, Ras Kigomasha, and Jozani.
From the moist green forests to the dry coral rag habitats, Zanzibar’s biodiversity is of international importance. The area of Zanzibar supports varying habitats, which in turn support a rich diversity of plants and animals. This is a result of the island’s past geological history when Zanzibar was part of the African mainland. Over time, the split from the mainland and movements in the earth’s crust resulted in Zanzibar being covered in a variety of soils, which formed the basis of the island’s great diversity of habitats. Today, Zanzibar has some of the last remaining tropical rainforest in East Africa and an array of other crucial habitats which remain in patches around the islands.
There is a total of 545 native and introduced flowering plants recorded from Zanzibar, Pemba and Mafia. The largest remaining tract of the original vegetation of the islands is the Jozani Forest and includes a special type of forest known as ground water forest which occurs in the coral rag regions of the islands. A floristic study of the Jozani Forest estimated the number of plant species to be around 200. Around 100 of these were originally forest species, of which 20 were trees and 80 large shrubs. Seven true forest tree species were recorded. A combination of factors restricts the dry coral rag regions of Zanzibar to a very depauperate flora of 20-50 native tree species, which compares to 100-140 species in more mesic regions. The Zanzibar Floristic Region is characterised by 69 (12.7%) endemic or near endemic vascular plant species. This is a high percentage for a small island group and is due to a combination of their isolation, speciation and extinction patterns and changes in sea level such that the islands have acted as both a refuge and a ‘launch pad’ for taxa. One of the most modern changes to Zanzibar’s vegetation has been the development of clove plantations. Cloves are the dried unopened flowers of a scented evergreen tree and are a valuable spice in international trade. Zanzibar is famed for its cloves and the crop has become a cultural icon for the islands. Clove growing began in 1818 under a government monopoly and this led to wholesale destruction of the forests and their replacement with the spice. In 20 years from 1880 the area of forest halved and by 1977 it was estimated that 50% of the total tree cover of Zanzibar had been lost to agriculture.
Zanzibar’s endemic and threatened fauna include the Zanzibar Red Colobus monkey, small and elusive Zanzibar leopard, and the recently extinct Zanzibar or Seychelles black colobus. The Zanzibar Red Colobus (Piliocolobus kirkii) is the most threatened taxon of primates in Africa, with possibly only a few hundred individuals remaining. They are now confined to a few forest fragments in Unguja, and one population on a small island off the western coast of Unguja known as Tumbatu. This species is a popular primate for ecotourists, and they are sometimes seen in larger hotels around the South and East coast where there are remnant pockets of forest. The Zanzibar Red Colobus is also important for seed dispersal in the forest ecosystem.
The forests and woodlands of Zanzibar are home to a variety of fauna; some are resident and some are migratory. Some species of fauna have become extinct and many are currently under threat. About 50% of Zanzibar’s original forest cover has been lost, resulting in habitat destruction for the wildlife. The remaining forests are highly fragmented and are under further threat. The islands have a single terrestrial mammal species, a type of Pemba flying fox (bat).
The Zanzibar red colobus Procolobus kirkii is often the flagship species when it comes to conservation in Zanzibar. This primate is endemic to Zanzibar and is confined to three remnant populations of between 1000-1500 individuals in the south west of Unguja. Due to the historical preference of the cloves the forest over which the colobus is found has been retained although heavily degraded. A recent study using satellite imagery by Arcus and UDSM has shown that 50% of the forest area used by colobus between 1985 and 1992 was lost. The colobus forest is also under threat from clearance to provide building materials and agriculture for local communities. High levels of poverty and little interest from the Government mean that this will be a difficult trend to reverse.
From the WWF-ICIPE surveys, Birdlife International produced an assessment of the conservation status of the birds. Out of the 208 species of bird that were recorded, 7 are globally threatened. Although none were found to be endemic to Zanzibar, several have very restricted ranges. The Zanzibar red bishop (Euplectes nigroventris) and the Sokoke pipit (Anthus sokokensis) are known from only the Mkondezi valley in the North of Pemba and are both globally threatened with extinction.
The most critical problem in the Zanzibar forest ecosystem is the high rate of endemism of the various taxa coupled with habitat loss. Many of the species found in the Zanzibar forests and woodlands are not found anywhere else in the world. Sadler (1993) states that “Zanzibar has two endemic species of mammals, three species of birds and 11 species of butterflies, all of which are confined to the small areas of evergreen forests in the East and north of Unguja.
Mangrove forests are found mainly along the sheltered west and southeast coasts of the main islands and on numerous islets. They grow on alluvial soils, particularly on the deeply waterlogged, anaerobic sediments of estuaries and sheltered bays. There are approximately 270 km² of Zanzibar mangrove forest providing a variety of goods and services to the local people. The expression “mangrove” actually refers to a variety of plant species that are adapted to the often harsh conditions of the seashore. Some varieties are able to filter the salt from seawater to enable survival, while others have special root systems which enable them to “breathe” in waterlogged, saline sediments. Coastal forests are located on the leeward shore of the islands, i.e. to the northwest of Unguja and to the west and southwest of Pemba. This forest type is evergreen but is subject to a prolonged dry season. Historically, the coastal forest type was the most extensive on the islands, providing the habitat for a wide variety of animals, many of which are no longer present today. Much of the land has now been converted to either agriculture or tourist development due to the desirability of coastal areas. Coastal forests are also susceptible to cyclone damage, which occurs on average approximately every 7 years. Lowland rainforests occur generally on the windward, eastern shores of the islands. This is the most fertile part of the islands, and the area historically supported the densest human population. The majority of the original forest has long since been removed to support agriculture; however, good examples are still present in some of the remoter parts of the island. Lowland rainforest is characterized by its high biodiversity of both plant and animal species. The trees are of enormous size, and there is a continuous closed canopy. The forest remains evergreen in the absence of a true dry season. Many of the tree species have developed buttress and prop roots to support their enormous size in the nutrient-rich soils.
Mangroves are interface plants, which separate marine and freshwater environments. These plants are a distinctive group of tree and shrub species that possess special morphological, physiological, and reproductive adaptations, enabling them to cope with the harsh conditions of the coastal environment – unstable mineral substrate, high salinity, and frequent inundation. Mangroves only exist in the intertidal zones in the tropics where tidal amplitude is at least 30 cm; however, they reach their greatest development in the Indo-West Pacific region. Globally, mangroves are being logged or converted to agriculture at a rapid rate, making this one of the most threatened tropical ecosystems. In Zanzibar, mangroves primarily grow on the sheltered western shore of Unguja. They are most easily observed at low tide when the huge, pencil-like pneumatophores that project from the mud surface can be seen. These are the aerial roots of the trees that enable them to obtain oxygen, which is lacking in waterlogged mud. It is estimated that up to 12 species of mangrove may grow in Zanzibar; however, accurate identification is difficult and more detailed surveys are required.
Zanzibar’s coastal forests (Miamuna and Ng’amba) are currently thought to be the second most degraded forest type on the islands. They are dominated by Cocos nucifera with few indigenous trees remaining. The coconut trees were planted by the previous owners of the forests who used the land for the cultivation of coconuts. This practice was highly detrimental to the forests and almost all of the indigenous trees were cleared for coconut plantations. There are however still some areas of coastal forest which remain and there is a strong desire from local communities for forest rehabilitation in these areas. Cocos nucifera plantations should not be confused with plantations of indigenous forest types in Zanzibar. Cocos nucifera plantations are generally a single storey with an open canopy and very little understorey vegetation. The structure of the coastal forests with remain is very similar allowing for a far greater ease of rehabilitation than for complex multistoreyed indigenous forest types. The Ng’ambo forest particularly is situated in an area of mostly agricultural land and the forest is surrounded by farming communities. In this situation, the forest edge communities can benefit from forest rehabilitation projects and the remainder of the agricultural land is of relatively poor quality. Coastal forests are situated on the western and eastern coastlines and many have been cleared for agriculture, particularly cultivation of seaweed in more recent times. The Kalinzi and Kangagani forests are good examples of the remnant forests on the east coast. There are mature forest reserves on Changu Island and in Kiwengwa which have a predominantly indigenous tree species composition. These forests have been well maintained by the Department of Commercial Crops, Spices, Forests, and Beekeeping who have implemented Forest Management Plans for the sustainable utilization of forest resources and protection of the environmental values of the forest. An agreement between DCCB and Kikwembe Forest Reserve exists to implement a tree planting project in an attempt to replace some of the previously felled trees, both indigenous and exotic. This is seen as a way to increase the overall timber and non-timber resource base of the forest and to capture and store carbon.
The lowland rainforests of Zanzibar are among the last of their kind anywhere in the world and are botanically and ecologically the most complex of the different types of forest on the islands. They are also the most threatened and least understood. Despite their immense importance, there has been relatively little research or scientific study of the Zanzibar forests, but what is clear is that the remaining areas are only a fraction of their original extent and are under severe threat from agricultural encroachment and timber extraction for a variety of uses. Lowland forest once covered virtually the entire land surface of both Zanzibar and Pemba up to an elevation of around 300m. Today there are only small patches of undisturbed forest remaining, most of them in the inaccessible areas of the escarpments of west-central Zanzibar and the southwest of Pemba. There are myriad small valleys running through and between coral rag and farmland, and most have had at least some disturbance, ranging from complete clearance to selective logging of valuable trees such as teak or mahogany. In some areas, the intact canopy gives a clear indication of the former extent of the forest and the density of indigenous species, but in many parts, the natural forest has been replaced by cash crop cultivation, especially cloves. It is very difficult to give an accurate figure on current forest cover, but best estimates are in the region of 5-10% of the total land area of both Zanzibar and Pemba.
They are found between 300-900m altitude and are typically communities from the next places in the sequence: Old Cardamom Forests, Transition Forests and then the climax association at Upland Bantu Core Zone. Series from the lowlands is often the result of long-term human utilization. The Upland Bantu Core Zone association is widespread and rich in species (c. 60 per 0.1ha) and dominated by Podocarpus gracilior. There are however, many places in the uplands where the climax association or sub-association have been disturbed to the extent that the forest has lost its chief characteristic, usually through the intensive cutting of one or two valuable timber species. An example is the Mufindi Highlands where P. gracilior has been extensively cut and where the presence of commercial exotic trees means that the true climax association may never return. Another example occurs at Amani where the disturbance has been the result of shifting agriculture replacing the climax association with regenerating disturbed forest up to the Transition Forest association. Upland forests are rarer and generally less disturbed than those in the lowlands. The Zanzibar Fauna and Flora Conservation Programme has created a classification and mapping system which is digitized and uses GIS and GPS technology for the precise location and delineation of forest types and disturbance categories. This will create a valuable resource which can be used to monitor changes in the extent and state of Zanzibar forests and is being used as a basis for the preparation of Forest Plans which commence with the Upland Bantu Core Zone association on Pemba Island. Economic and ecological zoning the forest is a step towards sustainable management and offers the possibility of reversing the current trend of declining forest.
In Zanzibar, ecosystem services are delivered from the forest and woodland habitats. These services are direct and indirect contributions from the natural ecosystems to human well-being. It is clear that the value of the services provided by Zanzibar’s forests and woodlands are valued at millions of US dollars annually. One of the forests’ primary and most significant forms of ecosystem service is carbon sequestration. Carbon sequestration is the capture of CO2 from the atmosphere and the storage of it in the forest ecosystem. The amount of carbon dioxide in the atmosphere has increased since the industrial revolution and it is a well-known fact that trees and forests have a key role in reducing the amount of CO2 in the atmosphere. The more trees there are, the more CO2 can be removed from the atmosphere. At the Copenhagen conference of 2009, it was agreed that a policy to reduce deforestation in developing countries’ carbon emissions would be written. This policy would mean that developed countries could offset their carbon emissions by paying developing countries to protect and maintain the forests. This, in turn, would mean that forests would have a monetary value for the carbon services they provide. In order for countries to participate in the REDD policy, there is a need to measure the amount of carbon stored in the forest and the amount of carbon that would be released if the forests were cleared. This involves creating a national carbon inventory and optimally, a continuous forest carbon monitoring system. This would most likely involve the utilization of satellite imagery and monitoring of ground plots. Although in its early stages, COMDEKS has been looking at various projects that aim to give village communities support in the management of their forest resources. One of their goals is to strengthen the capacity of local institutions for the sustainable management of forest resources and to enhance income for rural households through the development of village-based forest enterprises. Triggering REDD programs will generally mean that the value of the carbon sequestration services in Zanzibar’s forests can only go up.
A fairly recent concept with very profound implications for global climate change, carbon sequestration is likely to become one of the most important ecosystem services. Essentially, it is the removal of carbon dioxide from the atmosphere via photosynthesis and storage in plant tissues (Dixon et al., 1994). Since the ratification of the Kyoto Protocol, there has been a move towards reducing levels of carbon emissions in developed countries through agreements such as emissions trading or clean development mechanisms. A by-product of this movement is the increasing value placed on carbon sequestration in temperate and tropical forests. In the case of Zanzibar’s forests and woodlands, this could be potentially significant. Using the methodology outlined by Pagiola (2008), we can estimate the value of carbon sequestration in Zanzibar’s forests. A survey in the Mangrove forest found that carbon stock was 159.3 tonnes per hectare. This is very high in comparison to other forests in developing nations, due to its species richness, high productivity, and the anoxic, thus slow decaying, conditions of the soil. With an estimated area of 4140.8 hectares in the 1980s, Pagiola gives a conservative value of 100 tonnes per hectare and suggests an average sequestration rate of 0.5% of the carbon stock. Multiplying these figures out through time and summing over 30 years provides a total value of carbon sequestration of $31.44 million USD.
Zanzibar has seen a number of changes in land use over the past century. The large-scale logging of the 1800s was followed by extensive clearing for clove cultivation, subsistence farming, and firewood collection in the 1900s. More recently there has been conversion of forest to cultivated land and shifting agriculture. These activities have resulted in a decrease in base flow in streams, increased flood frequency, and siltation in river channels in a number of areas. The construction of roads in forested areas invariably results in increased surface water runoff and stream sedimentation. These changes to Zanzibar’s landscape occur when there is a disturbance to the natural equilibrium of water movement and storage in the landscape and are often associated with negative effects on both people and aquatic ecosystems.
The human disturbance of Zanzibar’s forests has had the effect of reducing water storage and its controlled release as well as increasing overland flows. These occur mainly on the higher permeability soils in the form of flash floods and are associated with soil erosion. The process of deforestation and subsequent conversion of montane forest to cropland has been identified as leading to increased frequency and magnitude of flood events in the wet season as well as decreased dry season flows in the catchments of small streams in a number of areas. A significant associated effect of deforestation is stream siltation. This occurs when sediment is eroded from bare ground during rain and is washed into river channels where it is then carried downstream and finally deposited. The eroded soil reduces channel.
The regulation of water occurs in a number of ways in ecosystems. The effects of forests on various aquatic processes have global implications as well as being particularly important to human societies. Forests generally increase the recharge of aquifers and the flow of streams. They do this by increasing infiltration and storage of water in the soil and by reducing losses from overland flow and evaporation. Water stored in the subsurface and released slowly is of particular value to people as it is the primary source of water for domestic, agricultural, and industrial uses as well as maintaining base flow in streams. Loss of base flow, particularly in regions with a seasonal climate, can result in stream drying with negative effects on aquatic biota. The value of forests in water storage and regulation is now widely acknowledged and in some countries this has led to the protection of forests in upstream catchments to safeguard water supplies.
Zanzibar’s high potential for ecotourism was first identified by Howell and van Ark in 1982. They proposed two tours of the islands, one of the historical sites and another around the nature reserves, although the latter made little progress. This is somewhat surprising because the Jozani Forest tour was and still is popular with independent travellers, who often, without official permission, employ local people to guide them through the forest in search of Red Colobus Monkeys. An ecotourism project began in the early 1990s, with surveys of the Pemba nature reserves by the government and the World Wide Fund for Nature (WWF). In 1995, a management plan for the reserves was outlined which included village land-use planning at five of the reserves, boundary demarcation at one reserve, village environmental education, and reserve-sponsored infrastructure development. The objective of this plan was to safeguard the reserves and discourage shifting cultivation and exploitation of timber and fuel wood in the forest by providing alternative sources of energy and income. Unfortunately, the violent political climate in Pemba in the late 1990s prevented the implementation of this project.
The conservation of remaining forests and woodlands is perhaps the most critical aspect of preserving the biophysical and social environment of Zanzibar. There are encouraging signs that lessons have been learned from a history of destructive resource use. The two forest reserves on Zanzibar are the focus for the majority of conservation activity. Efforts are being made to involve surrounding communities in the sustainable use of reserve resources, while the potential for extending the protected area network is being investigated. Conservation activity in the remaining woodlands is more complex due to the multiple-use nature of the resource and the fact that woodland is state or privately owned. The majority of woodland owners are subsistence farmers who have little incentive to preserve tree cover if it conflicts with their immediate land use needs. The concept of community-based forest management is more relevant to woodland areas.
The rich mosaic of ecosystems in the Wami Maintenance Area of Saadani National Park is a microcosm of East Africa’s coastal zone. It covers large areas of marshlands, riverine forests and a myriad of unique salt pans. Changing land use has left its mark on this area with extensive areas of overgrazed land but a portion of this zone has been set aside as a Controlled Hunting Area, which the park management plans to incorporate into the park’s allocation. At a regional level, the goal is to catalyze sustainable land use across all former land use types and secure the future of the remaining coastal ecosystems, which are of major environmental importance due to the heavy levels of human utilization in the coastal zone.
Saadani National Park was the first site to comprise a mosaic of former land use categories including agricultural land, coastal and mangrove forest, utilised and abandoned grassland, forested land, and village areas. The park has a diverse fauna. Ungulates include the blue duiker, Kirks dik-dik, Swayne’s hartebeest, waterbuck, reedbuck, greater kudu, eland, sable antelope, zebra, buffalo, giraffe and Tragelaphus spp. Other large mammals recorded in the mangrove areas along the Wami River include giraffe, elephant, buffalo and an occasional leopard. Lions are also known to reside in the area. The Wami River, navigable for about 48 km from the sea, contains large populations of crocodile and hippopotamus. Red monkey, baboon and vervet monkeys are common. Large herds of buffalo, wildebeest and zebra live in Saadani. The green turtle is known to breed off the coast during the night. Sea and shore birds are present. Saadani has a variety of reptiles, amphibians as well as invertebrates in particular, butterflies. Owing to the varied vegetation types in and around the park, Saadani has a diverse flora. At Saadani the Wami River forms a broad delta, though this area is only declared an Environmental Management Area, is an integral part of the parks ecosystems.
Community involvement is encouraged through the formation of Village Land Forest Reserves (VLFR), which are an innovative approach to the conservation of high forest biodiversity in a legally secure environment that recognizes customary land and resource rights. Forest adjacent villages are able to formally allocate village land in trust to the President, who assigns the land as a forest reserve managed by the village. This enables the management of the reserve by a legal entity comprised of the adjacent villages and provides villagers with increased security over their rights to use and manage forest resources. VLFRs also enable the villages to make contracts with third parties for the sustainable use of forest resources or joint management agreements with government or NGOs and private management to achieve sustainable conservation and development. This should enable a more equitable sharing of costs, benefits, and responsibilities between various stakeholders.
The Forest Policy and Forest Act were created in 1998 to provide for the conservation and sustainable management of the forest resources. These laws replaced the outdated forest ordinance of 1953, which was geared towards the exploitation of a seemingly inexhaustible forest resource rather than its sustainable management. The act aims to strengthen, develop, and conserve forest resources and their contribution to social, ecological, and economic development. This will be achieved through involvement and support of local communities, decentralization and devolution of central government authority to a regional and district level, provision of formal protection to unique or fragile ecosystems, habitats of rare and endangered species, and protection and rehabilitation of important forest catchment.
During the past decade, global climate change has emerged as a key driver of environmental change. There is now compelling evidence that the global climate is changing, as shown in temperature increases, changing precipitation patterns, and more frequent and severe El Niño events. Analysis of meteorological data from the U.S. National Oceanic and Atmospheric Administration’s Climate Diagnostics Center shows that average temperatures for Zanzibar have increased by 0.6°C over the past 30 years, whilst data from the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) shows a decline in mean annual rainfall of more than 200mm during the past 80 years. While the impact of these changes on the Islands’ climate is not fully understood, there is widespread concern about reduced availability of fresh water, and impacts on the frequency and intensity of extreme weather events. The effects of these changes are expected to have profound implications for Zanzibar’s forests. Increased greenhouse gas emissions are predicted to result in significant changes to the composition, structure and distribution of forests and woodlands around the world. The ability of a particular forest to adapt to climate change will depend on the tree species, the site conditions and the specific effects of climate change in the region. Lowland forests such as those found on Unguja are particularly sensitive to climate change due to the reduced temperature stability and higher vulnerability to drought.