General introduction
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| General introduction 3 1.1. BACKGROUND During the last few decades, deforestation in tropical rain forest areas has accelerated at an alarming rate. Extensive areas of forest are being cleared every year and there is no reason to believe that this disastrous process will stop or even reduce in the near future. It has been estimated that more than 11 million hectares of forest have been cleared in the world between 1986-1990 of which 5 millions have become fallow (FAO, 1993). Furthermore, some 15-20% of species is likely to become extinct even before they are known to science (Davis et al., 1994). With the growing awareness of the problem, tropical rain forest biodiversity is of great concern and its conservation has become an issue of increasing priority, though little has been done to counter the rapid disappearance of these rich ecosystems. The rain forest in Cameroon covers about 175,000 km ²representing about 37% of the national territory (Gartlan, 1992). Uncontrolled logging and land conversion for agriculture are leading to forest degradation and deforestation. Estimates put the remaining areas of forest at about 160,000 km ² with a further 60,000 km² currently under concession to timber companies (Sunderland et al., 1997) The Campo-Ma’an rain forest in south-western Cameroon covers about 7700 km ² and is situated in the middle of the Biafran rain forest belt that extends from Southeast Nigeria to Gabon and the Mayombe area in Congo. The site is unique, combining many vegetation types with species of high conservation priorities such as endemic, rare, new and threatened plant species. It contains about 114 endemic species, 29 of which are only known from the area, 29 only occur in the southwestern part of Cameroon, and 56 are near endemics that also occur in other parts of Cameroon (Chapter 5). The site is also known for its rich fauna with 4 endemic fish species and 2 endemic bat species (Vivien, 1991; Djama, 2001; de Kam et al., 2002). In addition, there are about 300 bird species of which 24 are rare or endangered (Languy & Demey, 2000). Thirteen threatened mammal species were listed in IUCN (2002), and up to half of the total mammal species found in Cameroon and two-thirds of those found in dense forest are recorded in the area (Vivien, 1991; Matthews & Matthews, 2000). The explanation for this high incidence of endemism and richness might stem partly from the fact that the site is part of a series of postulated rain forest refuge areas in Central and West Africa (Hamilton, 1982; Maley, 1987 & 1989; and Sosef, 1994). The conservation value of the Campo-Ma’an forest is high at local, national, regional and global levels. The area is recognised to be an important site within the Guineo-Congolian Regional Centre of Endemism (White, 1979 & 1983). However, despite its great biological importance, the Campo-Ma’an rain forest has suffered and continues to suffer from intense human pressure that has led to the degradation of most of the forest along the coast and the lowland forest around settlements. The main conservation effort so far has been the creation of the Campo Faunal Reserve in 1932 to protect its rich fauna, and the Ma’an Production Reserve in 1980 to protect populations of the economically important timber species Aucoumea klaineana (Okoumé). These two reserves are currently merged into a single Technical Operational Unit (TOU) that was created in August 1999. Later on, the Campo-Ma’an National Park was created within this TOU in January 2000. So far, Plant diversity in a Central African rain forest: Implications for biodiversity conservation in Cameroon 4 the National Park exists only on paper since in reality it has not yet been gazetted, and it has no boundary and management plan. Official control is weak and as a result, there is an increasing pressure on the forest ecosystem. However, since the creation of the TOU, the Campo-Ma’an Biodiversity Conservation and Management Project is working with the local communities and other stakeholders in order to prepare a strategic plan of the TOU and a management plan for the National Park. Although in the past some botanical research and collecting activities have been mainly carried out in the Edea-Kribi and Campo-Kribi-Akom II-Bipindi-Lolodorf areas, limited work has been done to describe and map the vegetation and flora of the Campo-Ma’an forest. There was still a large knowledge gap since very little was known about the biodiversity of the area. Therefore, taxonomic and ecological research has to be carried out to identify conservation priorities and hotspots for biodiversity conservation. Research objectives The main objective of this research was to assess the botanical diversity both in terms of vegetation and flora of the Campo-Ma’an rain forest in order to identify, locate and map biodiversity hotspots. More specifically, the aims of this study were: • to assess the botanical diversity of the Campo-Ma’an rain forest, describe the vegetation and identify plant species with a high conservation priority such as endemic, rare, threatened and species new to science; • to produce a plant species checklist of the Campo-Ma’an area with a red data list highlighting the conservation status of species with a high conservation priority; • to map the distribution of these high conservation priority species and locate hotspots for biodiversity conservation; • to provide baseline biological information, essential for the elaboration of the Campo-Ma’an strategic and management plans; • to provide recommendations for the conservation and sustainable management of its natural resources and threatened species. 1.2. STUDY AREA Location, policy and administrative framework Cameroon has ratified or is a signatory of a number of international treaties affecting environmental issues amongst which the most important are the Convention on Biological Diversity and the Convention on International Trade in Endangered Species of Wild Fauna and Flora. In response to the increasing international concern for the protection of the global biological resources, the government of Cameroon began a series of reforms in 1990 aimed at ensuring the sustainable management of its natural resources. A Ministry of Environment and Forestry (MINEF) was created in 1992, a National Environmental Management Plan (NEMP) and a National Forestry Action Program (NFAP) were launched in 1995. Furthermore, a new forestry law based on a new policy, which explicitly recognises the unique richness and importance of the nation’s biodiversity, and assigns a high priority to the protection of this heritage, was produced in 1994 (République du Cameroun, 1994, 1995 a & b and 1996). It is within this framework that a joint initiative of the Global General introduction 5 Environment Facility (GEF)-World Bank Biodiversity and Management Project and the government of Cameroon led to the creation of several conservation projects in Cameroon, and to the Campo-Ma’an Biodiversity Conservation and Management Project in 1996. Its objective is to ensure the conservation of biodiversity in the TOU and the sustainable management of its natural resources. The Campo-Ma’an area is located between latitudes 2°10’-2°52’ N and longitudes 9°50’-10°54’ E. It is bounded to the west by the Atlantic Ocean and to the south by the border with Equatorial Guinea (Figure 1.1). As shown in Table1.1 and Figure 1.1, the main components of the TOU are a National Park, five forest management units (FMU) and two agro-industrial plantations. Table 1.1 Present land use planning of the Campo-Ma’an Technical Operational Unit (TOU) Land use Area (ha) % of TOU Campo-Ma’an National Park 261443 34.0 Logging concessions (FMU 09021-25) 241809 31.4 FMU 09021 (Wijma) 42410 5.5 FMU 09022 (not yet attributed) 14514 1.9 FMU 09023 (Bubinga/HFC) 11777 1.5 FMU 09024 (HFC) 76806 10.0 FMU 09025 (HFC) 96302 12.5 Agro-forestry zone 196155 25.5 Agro-industrial plantations 57750 7.5 HEVECAM (Rubber plantation) 41339 5.4 SOCAPALM (Oil palm plantation) 16411 2.1 Proposed protected area 11968 1.6 Coastal zone 320 - Total 769445 100 Adapted from de Kam et al. (2002). HEVECAM (Hévéa du Cameroun) and SOCAPALM (Société Camerounaise des Palmeraies). The Campo-Ma’an National Park covers about 261,443 ha. It is a permanent state forest that represents 34% of the TOU and is solely used for forest conservation and wildlife protection. The following activities are therefore forbidden: logging, hunting and fishing, mineral exploitation, pastoral industrial, agricultural and other forestry activities. The logging concessions that are also called “Forestry management unit” (FMU) represent about 31.4% of the area. Agro-forestry zones are part of the non-permanent forest estate that can be used for purposes other than forestry. Added to agro-industrial plantations they represent 33% of the TOU and are mainly allocated for human activities such as agro-industry, agriculture, agro- forestry, community forest, communal forest, or private forest. The coastal zone is a narrow strip along the Atlantic Ocean from the Lobe waterfalls to the Ntem estuary in the Dipikar islands. It measures about 65 km long and extends about 2-3 km inland. The coastline is one of the most important marine turtle breeding habitats in Central Africa where four species of marine turtles come to feed or nest every year. Plant diversity in a Central African rain forest: Implications for biodiversity conservation in Cameroon 6 Figure 1.1 Present land use planning map of the Campo-Ma’an Technical Operational Unit (Annex 4). Physical environment Geology and soils The Campo-Ma’an area is situated on the Precambrian shield, which is the most important and extensive geological formation in Cameroon. This Precambrian basement complex consists mainly of metamorphic rocks and old volcanic intrusions (Franqueville, 1973). Metamorphic rocks such as gneisses, migmatites, schists and quartzites dominate the geology in the area. Soils that are developed on these metamorphic rocks are acid and poor in nutrients. Sedimentary rocks of the Cretaceous can also be found in the Campo basin. The topography ranges from undulating to rolling in the lowland area, to steeply dissect in the more mountainous areas. In the Campo area, altitudes are mostly low, ranging from 0 m at sea level to about 500 m. In the eastern part, which is quite mountainous, the altitude varies between 400-1100 m and the rolling and steep terrain brings about a more variable landscape. Following the FAO classification system, soils in the Campo-Ma’an area are generally classified as Ferrasols and Acrisols (Franqueville, 1973; Muller, 1979; van Gemerden & Hazeu, 1999). They are strongly weathered, deep to very deep and clayey in texture (except at the seashores and in river valleys where they are mainly sandy), acid and low in nutrients with pH (H 2 O) values generally around 4. Although Ferric soils are the most widespread, poorly drained as Dystric Fluviosols or Gleyic Cambisols soils are commonly found in the river valleys and adjacent swampy areas throughout the Campo-Ma’an area. The dominant soils in the coastal General introduction 7 plain are Plinthic Ferrasols, with patches of Haplic Acrisols and Acri-Xanthic Ferrasols. In the eastern part of the Campo-Ma’an area, soils are developed on ectinites including gneiss, micashist and quartzite. In the mountainous area, soils are developed on migmatites and granites and are mostly classified as Acri-Xanthic Ferrasols and Xanthic Ferrasols. Climate and hydrology The Campo-Ma’an area has a typical equatorial climate with two distinct dry seasons (November-March and July-mid-August) and two wet seasons (April-June and mid-August-October). The average annual rainfall generally decreases with an increasing distance from the coast, ranging from 2950 mm/year in Kribi and 2800 mm in Campo to 1670 mm in Nyabissan in the Ma’an area. The Ma’an forest has significantly less rainfall than other areas. This is probably due to a rain shadow effect caused by the Nkolebengue Hills (up to 1000 m) which forms a substantial upland block between Ma’an and the ocean. The average annual temperature is about 25°C and there is little variation between years. The hydrography of the area shows a dense pattern with many rivers, small river basins, fast-flowing creeks and rivers in rocky beds containing many rapids and small waterfalls. The main rivers draining the TOU are the Ntem, Lobe, Bongola, Biwome, Ndjo’o, Mvila and Nye’ete. Swamps are commonly found in the valley of these rivers. Socio-economic settings Population, ethnicity and settlements A recent census carried out by ERE Développement in April 2001 has shown that about 61,000 people live in 167 towns, villages and agro-industrial or logging camps. Generally, the area has a low population density of about 10 inhabitants per km² and is sparsely populated with most people living around Kribi, along the coast, and in HEVECAM, SOCAPALM and HFC camps (ERE Développement, 2002; de Kam et al., 2002). There are seven main ethnic groups in the area which are the Batanga, Mabea (or Mabi), Mvae, Yassa, Ntumu, Bulu and the Bagyeli (or Bakola) Pygmies. In addition to these ethnic groups, there are residents from other parts of Cameroon and Equatorial Guinea who depend on the work provided by the timber companies and agro-industrial plantations. The Bakola pygmies are mainly forest dwelling hunters and gatherers, although they seem to be in the process of sedentarisation (Annaud & Carriere, 2000). They are in small number and depend mostly on the forest for their livelihood. Their life style is seriously threatened by the ongoing logging activities. The Batanga, Mabea, and Yassa are mostly found in small fishing villages along the coast between Kribi and Campo. They rely mostly on the sea for their livelihood and have fishing as their main occupation. The Mvae, Ntumu and Bulu are mainly farmers, hunters and forest gatherers. Logging and agro-industrial enterprises There are two main logging enterprises in the Campo-Ma’an area which are “la Forestière de Campo” (HFC) and Wijma (GWZ). HFC is operational since 1966 and operates a sawmill and port facilities at Ipono near Campo. Other companies such as Wijma and CFK also have sawmill facilities. Log production is about 39,250 m³/year and more than 135,000 m³ of sawn woods are produced per year. Timber harvesting in the area provides about 115 millions FCFA/year ($ 201,754) to the Plant diversity in a Central African rain forest: Implications for biodiversity conservation in Cameroon 8 local communities concerned and direct employment of about 1000 jobs that represent wages of about 1 billion FCFA/year ($ 1,8 millions) (ERE Développement, 2002; de Kam et al., 2002). HEVECAM and SOCAPALM are the two main agro-industrial companies located in the area. They are the major employers in the area, developed many infrastructures, and provided many services in their area of activities. They employ about 5625 workers who earn wages totalling about 5,5 billions FCFA/year ($ 9,7 millions). Stakeholders In the Campo-Ma’an area, stakeholder groups range from direct users to people who will be indirectly affected by any management decision. Although the Campo- Ma’an project will need the full support and participation of the local population to achieve its goal, it is of vital importance to involve other potential stakeholders such as the local administrative authorities, logging and agro-industrial companies, local common initiative groups, NGO’s and other institutions which are operating in the area. Economic activities and their influence on biodiversity conservation Despite the low population density, there are few employment opportunities. The local people are very poor and so far rely solely on the forest resources to meet their basic needs. As a result, local pressure on the Campo-Ma’an rain forest is increasing and there are several activities that are carried out in the area with varying ecological impacts on the forest ecosystem. These activities include agriculture, logging, poaching and hunting. Agriculture Clearance of natural vegetation to provide land for industrial and subsistence agriculture is the biggest threat to the Campo-Ma’an forest. Large-scale agro- industrial plantations have destroyed about 7.5% of the forest cover. Small private owners are also involved in the clearing of a considerable portion of the coastal and lowland forests for the establishment of small plantations of oil palm, rubber or cash crops such as cocoa. The local population practises shifting or “slash and burn” agriculture in the area. It is a major cause of deforestation and forest degradation around settlements since it involves land conversion from forest to permanent agriculture land, reducing the soil fertility and the natural vegetation cover. Logging Timber exploitation is the main economic activity in the area and is dominated by HFC and Wijma. Logging concessions represent about 31.4% of the area. The southwestern part of the National Park and the coastal zone has been selectively logged at least twice during the past 30 years. Less than one tree/ha is felled and logging is limited to about 60 tree species (Jonkers & van Leersum, 2000). Although logging damage is moderate and has limited effect on the forest biodiversity (Jonkers & van Leersum, 2000; van Gemerden et al., 2003) any degree of damage represents a capital loss in terms of trees and deterioration of the biotic and physical environment. Logging creates skid trails that allow easy access for poachers, and encourage settlers to establish forest camps, villages and farms. Furthermore, felling damage includes breakage of saplings and residual stems and hinders the growth of seedlings by discarded crowns of felled trees (Parren, 2003). General introduction 9 Hunting and fishing Hunting is a major activity in the area. Several villages and local people are known to rely heavily on hunting as an important source of income and for subsistence. It is for the moment a lucrative way through which the local communities derive direct economic benefit from the forest. The use of cable snare trapping is the most common form of hunting in the area, and guns are mainly used during the night to kill large mammals. These animals are sold in urban areas where bush meat is in great demand. The use of indiscriminate and wasteful methods such as cable snares on long trap lines, as well as poaching, have severely depleted the primate and forest elephant populations in the area (Matthews & Matthews, 2000; Ngandjui et al., 2001). Fishing is the major economic activity in coastal villages. It is the main protein source and almost all local populations rely heavily on it for subsistence and as source of income. Fishing is also practised in some villages inland along the Ntem, Bongola, Lobe, Biwome and other rivers. Non Timber Forest Products (NTFPs) The Campo-Ma’an area has about 250 NTFPs (Tchouto et al., 2002 unpublished). These forest products form an integral part of the rural economy, and contribute to all aspects of rural life, providing food, fuel, building material, medicine, craft material, other household items, ornamental and horticultural plants. The collection of NTFPs is mostly done in the area for local consumption, but few local people rely on it as a source of income. So far the collection of NTFPs has little or no effect on the Campo-Ma’an forest and its ecosystem (Tchouto et al., 2002 unpublished). Tourism and ecotourism There is much potential for the development of tourism and in particular ecotourism in the Campo-Ma’an area. The site’s advantages for ecotourism include the presence of a National Park, a coastline of 65 km with attractive beaches, many waterfalls (Lobe and Memve’ele), diverse ethnic groups with different cultural heritage and the presence of archaeological sites. So far, tourist activity is poorly developed and ecotourism is almost absent. Tourist industry is only focused on some beaches around Kribi. For the moment, the local community derives very little or no benefit from such type of tourism. 1.3. HISTORY OF BOTANICAL RESEARCH IN THE CAMPO-MA’AN AREA The Campo-Ma’an area has been visited by many botanists over more than one century. The first collectors were Germans such as Braun (1887), Dinklage (1889- 93), Zenker (1896-1922) and Staudt (1895-96). Their botanical explorations were largely confined around Kribi, Bipindi and Lolodorf areas because of easy accessibility. Later on, French, Dutch and other German botanists also collected around Kribi, along the coast from Kribi to Campo in the former Campo Faunal Reserve area, and in southwestern Cameroon. They included Schlechter (1900), Schultze-Rhonhof (1911), Mildbraed (1911 & 1914), Ledermann (1912), Fleury (1917), Letouzey (1962-68), W.J. de Wilde (1963-64), Raynal (1963 & 1965), Leeuwenberg (1965), Bos (1968-70) and J.J.F.E de Wilde (1964-76). Among these first botanists, Letouzey was the only one who visited the Ma’an area. These collections were used for the production of 37 volumes of the Flore du Cameroun. Plant diversity in a Central African rain forest: Implications for biodiversity conservation in Cameroon 10 Recently other botanists such as Beentje (1980), Hall (1991), Thomas (1992), Wieringa (1994), van der Burgt (1997), Parren (1997), van Gemerden (1997-99), van Andel (2000-2001), and botanists from the National Herbarium in Yaounde also collected in the area. A first attempt to classify the vegetation types of Cameroon was made by Letouzey (1968 & 1985). He adopted the phytogeographic approach to interpret and map the vegetation of Cameroon at a scale of 1:500,000 with definitions and descriptions of the different vegetation types using black and white aerial photos taken during the 1960’s. It should be noted that he did not cover the country evenly during his field trips in various parts of Cameroon and apparently the Campo-Ma’an area was not fully investigated. However, he described and mapped several vegetation types and sub-types in the Campo-Ma’an area by using indicator species such as Calpocalyx heitzii and Sacoglottis gabonensis. The main vegetation type was defined as Atlantic Biafran forest rich in Caesalpinioideae with 5 sub-types dependent on the occurrence of Caesalpinioideae, Calpocalyx heitzii (Leguminosae-Mimosoideae), Sacoglottis gabonensis (Humiriaceae) and other coastal indicators. Kaji (1985) studied the floristic composition and the structure of the Atlantic Biafran forest rich in Caesalpinioideae with Calpocalyx heitzii and Sacoglottis gabonensis near Nkoelon and Mvini. In 1991, a three-month canopy raft expedition was organized in the former Campo Faunal Reserve by the “OPERATION CANOPEE” with the aim of carrying out scientific research in the canopy of a tropical rain forest. A canopy raft made of a hot air balloon was used to get access to the canopy in order to study the flora and its pollination ecology. 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