(Buddlejaceae) in Côte D'ivoire

Distribution, regeneration and conservation status of Nuxia congesta R. Br. ex Fresen. (Buddlejaceae) in Côte d’Ivoire Adou Yao C. Y.1,2,3 , N’Da D. H.1, Bakayoko A.2,4 , Kouassi K. E.1, N’Guessan K. E.1, Aké- Assi L.3 1Laboratoire de Botanique, UFR Biosciences, Université de Cocody-Abidjan, 22 BP 582 Abidjan 22, Côte d’Ivoire (e-mail: [email protected]) 2Centre Suisse de Recherches Scientifiques (C.S.R.S). 3Centre National de Floristique (C.N.F.) 4Laboratoire de Biologie végétale et Amélioration des Productions Agricoles, UFR Sciences de la Nature, Université d’Abobo-Adjamé, Côte d’Ivoire ABSTRACT

In Côte d’Ivoire, Nuxia congesta (Buddlejaceae) was known only on some highest peaks of the country (Mounts Tonkpi and Boho) until 2006. Recent studies conducted from January to June 2007 and in 2008 identified two new locations in the region of Marahoué (department of Bouaflé), relatively far from the previously known ones and confirmed the disappearance of the species in Mounts Tonkpi and Boho. The distribution of this species was mapped and some ecological characteristics observed in those different locations were specified. The conservation status of the species was also assessed and discussed on the basis of the threats that its habitats were liable to, using the criteria of the IUCN Red List. The species can be characterized as rare in Côte d’Ivoire.

Key words: Rare species, Conservation status, Nuxia congesta, Côte d’Ivoire

INTRODUCTION The evaluation of the state, of the trends of the biodiversity and the identification of the habitats The loss of the biodiversity is presently a crucial subjected to particular threats constitute the two main problem for conservationists and for ecologists. The objectives of the Convention on Biological Diversity biodiversity of Tropical African countries represents a (CDB, 2001). In this respect, three attributes of the very important part of the global biological diversity biodiversity particularly draw the attention of the (Myers et al., 2000; Brooks et al., 2001). The international community: the species’ richness, the knowledge of the biological diversity in tropical Africa richness of rare and endangered species, and the began with the works of the first colonial endemism (Caldecott et al., 1996). These rare and administrators. It continued with the first botanists threatened species are indicator species for the until present time. In Côte d’Ivoire, the botanical functioning of the ecosystems, and can inform about investigations began in 1882 with Chaper (Aké-Assi, an imminent degradation of the biodiversity elements 2001) in the regions of lagoons and continued on all (Golding, 2002). They are likely to replace those that the Ivorian territory. The collections allowed listing a are presently abundant in case of important change big quantity of plant species constituting the Ivorian in the ecological conditions. flora that is estimated at 3,853 species (Aké-Assi, 2001, 2002). If a significant number of the species of A red list of plant species is a fundamental tool for this flora is not threatened, a more reduced part biodiversity conservation. Indeed, in front of the high undergoes pressures due to the human activities on cost of the preservation of the habitats which contain the ecosystems that shelter them or directly on them. a biological diversity, these species have to benefit Other species are naturally rare or even threatened first and foremost from the efforts of conservation because living in fragile biotopes with fewer (Myers et al., 2000). For Côte d’Ivoire, there is a list populations. In this last group of habitats, the edges of rare and threatened species drawn up by Aké-Assi of rivers, mangrove, the swamp forests and (1998) and updated in 2001-2002. For western mountains appear as appropriate sites for choice Africa, there is also a list of Hawthorne (1996) and (Adou Yao et al., 2010). Poorter et al. (2004) who listed the rare, threatened Am. J. Sci. Ind. Res., 2011, 2(5): 774-785

and endemic species of western African forests. The conservation status of this species, its distribution, Red List of the IUCN lists on a precise criteria, the and its structural parameters, as well as its threats to the species. It thus allows to take companion species were analyzed in this study. measures and to establish conservation priorities MATERIEL AND METHODS (IUCN, 2001, 2003). The lists of fauna and flora are established for every State of the World. The IUCN Study area: The study took place in two densely list concerning the Ivorian flora published in 2009 populated administrative regions of Côte d’Ivoire: the contains 129 species among which the threat status regions of the ‘18 Montagnes’ and of the ‘Marahoué’ of 120 at least have to be updated because of the (Figure 1). The first region, as its name suggests, is lack of recent works. the highest peak in Côte d'Ivoire. The elevations range from 500 to 1,000 m a.s.l. Among plants which live in threatened covers such as the vegetation of mountain, there is Nuxia Several mountains can be met in the ‘18 Montagnes’ congesta (Buddlejaceae), an orophyte species, met such as Mount Tonkpi (1,189 m a.s.l) and Mount for the first time in Mounts Tonkpi and Boho in the Boho (760 m a.s.l.) near the village of Zoanlé (Zonlé) West of Côte d’Ivoire, in the region of Man. The about 24 km from the city of Man (Figure 2).

Fig 1: Map of population density and location of the administrative regions of the study sites.

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Fig 2: View of the landscape around Man from Mount Tonkpi (Photo Assi, 2009).

It can be noticed the mountainous landscape and the dominate. Until 2006, Nuxia congesta was known city of Man (in background). only on Mounts Tonkpi and Boho. Thanks to an The mean annual temperatures are about 27°C. The environmental impact study in the region of the region belongs to the mountainous sector of the ‘Marahoué’ in January 2007, the species was Guinean domain (Guillaumet and Adjanohoun, 1971), encountered randomly on the hills at 250 m and 600 which is covered by mountain vegetation as defined m a.s.l. by Yangambi (1956) (Guillaumet and Adjanohoun, Data collection: 1971). The summit of Mount Tonkpi includes, in Herbarium data: Materials of N. congesta from the addition to communications facilities, an interesting two following Herbaria specimens were studied agricultural station that hosts introduced species such (Table 1): National Herbarium of Côte d’Ivoire as quinquina (Cinchona officinalis and C. succirubra), (Herbarium Ivorensis, UCJ) located in the ‘Centre tea (Cameliea sinensis), pines (Pinus sylvestris, P. National de Floristique’ of the University of Cocody- patula).. The vegetation of Mount Tonkpi is a Abidjan and the National Herbarium of France transition to the semi-deciduous forest. Uapaca (Herbarium Musei Parisiensis, P) hosted by the esculenta, Uapaca guineensis, Chidlowia sanguinea, National Museum of Natural History in Paris. This Tarrietia utilis, and Chrysoplyllum perpulcrhum are review helped to notice the sites where the species the dominant species of this vegetation. samples were recorded. To identify the occurrence The second study site is located in the administrative zones in Africa and in World, on the basis of different Department of Bouaflé, precisely at Kossou, in the works (Palmer and Pitman, 1972, Bouquet and Centre West of Côte d’Ivoire. This zone belongs to Debray, 1974, Govaerts, 2006). Taxonomically, the mesophilic sector of the Guinean domain. Its Nuxia congesta belongs to plant families of vegetation corresponds to that of a mountain dry Buddlejaceae and Stilbaceae according to the forest occupying hilltops (N’Da et al., 2008) where classification adopted (Table 2). Zanthoxylum spp and Anthonotha crassifolia

Table 1: Summary of specimenas visa with information on places of deposit. Locality of harvest Collectors, n° de record, place of deposit Mount Tonkpi February 16th 1964 L. Aké-Assi 7361 UCJ Mount Tonkpi January 10th 1970 L. Aké-Assi 11006 UCJ Mount Tonkpi s.d. Leeuwenberg & Bouquet 3867 P Haut Sassandra, Mount Boho (760 m) near Zoanlé May 6th 1909 A. Chevalier 21494 P Mount Tonkpi December 1952 Miège & L. Aké-Assi 1986 P - 1932 Service Forestier Côte d’Ivoire1011 P Herbarium Musei Parisiensis (P), Herbarium Ivoriensis (UCJ).

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Table 2: Taxonomic position of Nuxia congesta R.Br. ex Fresen according to the classification of Cronquist (1981) or APG 3 (2009). Taxonomic position of Nuxia congesta according to of Taxonomic position of Nuxia congesta according to the CRONQUIST (1981) classification APG3 (2009)

Règne : Plantae Règne : Plantae Sous-règne : Tracheobionta Sous-règne : Tracheobionta Division : Magnoliophyta Division : Magnoliophyta Classe : Magnoliopsida Classe : Magnoliopsida Sous-classe : Asteridae Sous-classe : Asteridae Ordre : Scrophulariales Ordre : Lamiales Famille : Buddlejaceae Famille : Stilbaceae Genre : Nuxia Genre : Nuxia Espèce : Nuxia congesta Espèce : Nuxia congesta

Field data: The identified localities of occurrence of and on the sites of the region of the ‘Marahoué’. The Nuxia congesta and some other localities presenting mapping was performed using the software Excel similar elevations and vegetation were visited twice in and Arcview 3.2. the region of the ‘18 montagnes’ and its surroundings The works of Keay and Hepper (1954, 1972), White during 2006 and 2009. The visited sites of the ‘18 (1983), and Aké-Assi (2001, 2002) were used to montagnes’ were named S1 on mount Tonkpi and S2 supplement the localities of occurrence in Côte on mount Boho. d’Ivoire. Plant species richness and diversity in the 10 In the region of the ‘Marahoué’, eight (8) field visits circular plots were estimated using the software were conducted during 2007 and 2009, one visit Estimate S 8.10. Structural parameters of all every quarter. The surveys in this region were individuals of N. congesta on the sites S3, S4, and performed using a compass (for the direction) and S5 (densities, basal areas, tree stems distribution on GPS (for the record of geographical coordinates).The diameter classes) were computed. The density and sites were named S3, S4, and S5. The purpose of basal area of three species (one in the higher the surveys was to see if the sites still hosted N. stratum: Cola millenii, one in the medium: Baphia congesta. bancoensis, and one in the lower stratum: Based on the results of these surveys, the sites of the Lecaniodiscus cupanioides), among the most Marahoué area were chosen for botanical inventories frequent around N. congesta stems, were calculated. to describe habitats and threats to the species, to Similarly, a histogram showing the variation of determine the number of the individuals remaining, to altitudes in Africa for 92 records of the species map the distribution of the species and to identify the mentioned in the literature (Govaerts, 2006, GBIF species that live in its immediate vicinity. Data Portal, 2010) was drawn to identify preferential

elevations. Two inventory techniques were used: the itinerant The criteria of IUCN (2001, 2003) concerning rare inventory (Kouamé, 1998; Adou Yao et al., 2007) was and threatened species were used to assess the used to test in the sites if Nuxia congesta was still conservation status of Nuxia congesta on the Ivorian present. After noticing the occurrence of the plant, territory. Given the quality of the collected data, the the number of individuals was counted, and 10 criterion ''b'' which means the number of the national individuals were chosen randomly. Around those 10 localities of occurrence was taken into account. The individuals, circular plots (diameter of 10 m) were abundance of the species on different sites was also placed to record all the species present, and to count considered as well as the pressures of human the seedlings and saplings of N. congesta. In the 10 activities on it (gold mining, farming and wood plots, the threats that can affect the species and its harvesting for diverse purposes). habitat were noted to discuss the conservation status of the species. RESULTS

Data Analysis: The collected data help to map the Description of the species: Nuxia congesta is a distribution of Nuxia congesta on the Ivorian territory tree or shrub, 2–20 m high with fluted trunk (Figure 3)

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without buttresses up to 60 cm in diameter. It has a peak. The petioles measure 0.5 to 2 cm in length. pale grey-brown to dark brown shedding bark and The inflorescences are terminal or axillaries cymes, hairy branchlets. It is usually found in clumps of pubescent when young and glabrous when they are stems from a strain that outcrops above the ground mature. The flowers are small, about 5 mm long, or fully buried. The leaves are hairy, dark green, tubular and creamy white, often tinged with mauve or slightly leathery, variable in shape and size, and are purple, especially in bud. The calyx is 4 mm in length, usually found in whorls of 3. On the younger almost cylindrical, densely pubescent outside and specimens, the leaves are distinctly toothed and the hairy inside, with lobes well demarcated and erected. twigs are reddish while on the mature trees, the leaf The corolla is white to yellow with glabrous lobes margins are usually whole and rolled under it. The rounded above, and a glabrous ovary. The flowering leaf blades are narrowly elliptic and up to 14 cm long, time observed during this study goes from January to 2-4 cm wide, tapering gradually to an acuminate June.

Fig 3: View of two fluted trunks of Nuxia congesta R.Br. ex Fresen (Buddlejaceae) on the S3 site. (Photo: Adou Yao, 2008).

Distribution of Nuxia congesta within Africa In the World, the species can be met in Africa and in according to the literature: Several synonyms of the Arabian Peninsula. In Africa, it was recorded in Nuxia congesta can be found in the literature among more than 20 countries: the Centre, East, and South which Nuxia sambesina Gilg and Nuxia viscosa of the Continent. The species was said to be native Gibbs. It is a pioneer species that grows in the light of from Botswana, Ethiopia, Kenya, South Africa, the high lands, and on hilltops. On the sites of this Sudan, Swaziland, Tanzania, Uganda, Zimbabwe, in study, it was encountered on upper slopes and Eastern Africa. In West Africa, it was collected in hilltops. Nuxia congesta is also common on rocky Côte d'Ivoire, Ghana, Guinea, Nigeria, and Sierra ridges. Leone. In Central Africa, it is reported in Cameroon, Angola and DRC.

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Distribution of the species on the Ivorian Department of Bouaflé). Two other populations of the territory: In Côte d'Ivoire, Nuxia congesta was species were located on two hills in the south of reported in natural stations on Mount Tonkpi (7.45 ° villages named N'Da Koffi Yébouékro (S4) and N, -7.65 ° W: S1) at1,189 m a.s.l., Mount Boho (7.57 Bokasso (S5), in the same ‘Sub-prefecture of ° N, -7.7 W: S2) around the village Zoonlé (or Zoanlé) Kossou’ (Figure 5). The three sites of Kossou were at 760 m a.s.l. (Figure 4). The field surveys reported all hills whose altitudes were between 247 m and 484 the presence of the species on the hills, in the site of m a.s.l. In Côte d’Ivoire, no individual was recorded in the ‘sub-prefecture of Kossou.’ The first stations of plains and lowlands; it lived only on hills and occurrence were made of two hills in the area of the mountains. mine of Cluff Gold near the village Angovia (S3) in the ‘Sub-prefecture of Kossou’ (Administrative

Fig 4: Location of the N. congesta in the region of “18 Montagnes” according to herbarium specimens consulted.

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Fig 5: Map of village Angovia showing the sites of occurrences (S3, S4, and S5) of Nuxia congesta R.Br. ex Fresen (Buddlejaceae) in the “Sub-Prefecture” of Kossou.

Vegetation of occurrence sites and companion characteristic species, some frequent and abundant species: The sites of occurrence are covered by a species around N. congesta such as Monodora dry dense forest of mountain as noted by N’DA & al tenuifolia, Dialium guineense, Ochtocosmus (2008) but, it is more fragmented here. The higher africanus, Pouteria alnifolia, and Holarrhena stratum (about 20 m) is made of species such as floribunda. Nuxia congesta, Zanthoxylum xanthoxyloides, and Cola millenii. The medium stratum consists of Baphia Structural parameters bancoensis and Anthonotha macrophylla. The lower Stem density of Nuxia congesta: Tree stem stratum includes Olax subscorpiodea, Lecaniodiscus densities of Nuxia congesta in the three sites (S3, S4, cupanioides and herbs such as Olyra latifolia, and and S5) varied from 2.4 (S5) to 12.2 individuals (S3) young individuals of the species mentioned above. (table 3). The distribution of the individuals was Griffonia simplicifolia is the most abundant liana met mentioned on a map (Figure 6) for site S3 and in these vegetations. On the floor, there is a large presented a gregarious tendency. The species can amount of dry matter composed of dead leaves, subsist alone (cases of Ni3, Ni23, and Ni38) but, branches, and many termite mounds. usually, it was found in clumps of stems on the same underground strain (or plateau). Ni22 was the denser The inventory in the 10 circular plots allowed clump with eight (8) individuals in the same strain. recording 47 species on an area of 785.4 m2. It allowed identifying, in addition to the above

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Table 3: Summary of the taxon densities in the three sites of occurrence in the “sub-prefecture” of Kossou (region of Marahoué). Stations ni nb of tufts Surface Stem Densities Density of tufts Mean DBH (ha) S3 116 40 9.5 12.2 4.2 17.5* S4 9 3 2 4.5 1.5 7.7** S5 6 2 2.7 2.4 0.7 23.4* ni: number of stems ; nb tufts: number of tufts; * & ** mean DBH statistically different.

The density of the main associated species varying exceeded that of N. congesta (Table 4). However, between 203 and 1413 individuals/ha greatly their mean DBH was less.

Table 4: Comparison of densities, mean DBH and basal areas of Nuxia congesta and three companion species on the site S3. Number of Density Surface (ha) Mean DBH (cm) Basal area (m2/ha) Species individuals (stems/ha) Nuxia congesta 9.5 116 12.2 17.5a 3.7 Cola millenii 0.079 16 203.7 9.6b 2.3 Baphia bancoensis 0.079 111 1413.3 4.6c 3.2 Lecaniodiscus cupanioides 0.079 36 458.4 4.5c 1.1 a, b, c denote means that are statistically different.

Fig 6: Distribution map of the 40 tufts of N. congesta recorded on the site S3 within the exploitation perimeter of Cluff Gold.

Diameter classes and basal areas: The largest The distribution of stems in diameter classes showed diameter of S3 was 45.2 cm; those of S4 and S5 the absence of trees with very large diameters. Even were respectively 20.7 cm and 36.9 cm. The smaller mature and flourished, the diameters of trees did not diameters were 1.6 cm for S4, 3.5 for S3, and 4.8 for exceed 60 cm. S5. The mean diameters of the three occurrence sites are summarized in table 3. The mean diameter The histogram presented a bell shape centered on varied from 7.7 cm (S4) to 23.4 cm (S5). The stems the class [10-20 [, showing that trees with small and recorded in S4 were more numerous than those in S5 large diameters are fewer than the medium trees but the mean diameter in S5 was three times higher. (Figure 7).

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The total basal area of N. congesta stems on the (0.3 m2). The trees on S5 are larger than those on three sites is 4.07 m2. Per site the basal area of S3 is S4. 3.7 m2, far more important than S4 (0.06 m2) and S5

Fig 7: Cumulative diameter classes distribution of Nuxia congesta on the site of the “sub-prefecture” of Kossou.

Human population and threats to the species: The (January 2007 - December 2008), no fruits or seeds region of the ‘18 montagnes’ is populated by was observed. Similarly, during the surveys, it was 1,334,387 inhabitants in an area of 16,600 km2 (with sought in vain for seedlings. Another great threat to population density of 80.4 inhabitants/km2) (OFFICE the population of the species was the mine of Cluff NATIONAL DE L’IDENTIFICATION, 2010). That of Gold. Station S3 on which most of the individuals the ‘Marahoué’ covers an area of 8,500 km2 and were found was located on the perimeter bordering hosted 791,689 inhabitants with a density of 93.1 the mine gold around the village Angovia. inhabitants/km2 (Figure 1). Those population densities were higher than the national mean density DISCUSSION (63.8 inhabitants/km2). The first threat to the species Most consulted samples showed that the occurrence was the high population around the sites of of Nuxia congesta ranges from 152 to over 2,800 m occurrence and farming activities within the a.s.l. However, although it could be found at remaining forest patches which were not exploited elevations below 200 m (the case of Ghana: 152 m), until recently. The second threat to the species was the histogram of the number of samples based on the its phenology. During two years of monitoring on sites minimum altitudes of records (Figure 8) indicated that S3, S4, and S5, only a vegetative state (young and 65% were observed between 1,500 and 2,500 m old leaves) and flowering (flower buds or flowers) of a.s.l.: the preferential sites of occurrence of Nuxia the plant was met. During the period of study congesta in Africa were therefore highlands.

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Fig 8: Cumulative occurrences distribution of Nuxia congesta based on minimum elevations classes in Africa (data from GBIF Data Portal).

In Côte d'Ivoire, before this study, the species was This probably explains why N. congesta was found at the lowest altitude of 760 m a.s.l. on Mount subservient to the habitats of hills and mountains Boho. By observing Nuxia congesta at the elevations where light is received more easily. Information on between 247 and 484 m a.s.l., it could be said now population structure of a tree species indicates the that the occurrence of the species varies between history of the past disturbance to that species and the 247 and 1,100 m in the country. In addition, five sites environment and hence, used to forecast the future were known to harbor this species: Mounts Tonkpi, trend of the population of that particular species Boho, and the three hills of the ‘Sub-prefecture’ of (Tamrat Bekele, 1994; Demel Teketay, 1997). Kossou. Two of them were no longer likely to host The absence of seedlings was probably due to a high this plant. Indeed, because of human activities mortality at this age of growth. The Gaussian shape (farming on upper slopes and on summits of could also explain the absence of seedlings and mountains and hills), the surveys in these two latter saplings under and near mature trees. But as stations failed in observing the taxon. In the site S3, Hawthorne (1995) pointed out, an attention should be the species occupied the upper slopes and the paid because several other factors may have summit of a large hill within a perimeter of gold intervened. mining. It was therefore likely to disappear when the mine reaches this part that contained the largest The lack of fruits, seeds and seedlings around population. N. congesta occurred only in the dry mature trees created a serious threat of extinction to dense forests of the mountains, but with the intense the species. Indeed, during the mine activities, all the pressures on them, it remained only some fragments hills where the species were more found will be that were used as places for hunting activities. Many destroyed, so that the survival of the current sockets were collected in those fragments. population was seriously threatened. Farmers cultivate local rice named ‘Yowèrè rice’ on the high There was a relationship between the temperament slopes and even the tops of some hills. Nuxia of species and the distribution of their stems in congesta living only on such areas will disappear if diameter classes (Geldenhuys, 1992; Sokpon and no action is undertaken. Biaou, 2002; Adou Yao et al., 2007). A distribution presenting Gaussian or bell shape is generally In addition to deforestation, fires that were used for regarded as characterizing light demanding species. farming contributed to threaten a species whose

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population was already sparse nationally. Nuxia field guides for their valuable assistance. Our congesta was not the sole threatened species by thankfulness goes to anonymous people whose mining and agriculture activities. Fourteen (14) other critics and comments were helpful for this work. species were listed on the IUCN Redlist and recorded by N'Guessan et al. (2007) on the same site, were also threatened. There were 11 species in the REFERENCES category "vulnerable" and three of "LR". Yowèrè Adou Yao, C. Y. (2005). Pratiques paysannes et people living in this locality used only the stems of N. dynamiques de la biodiversité dans la forêt classée de congesta for construction. Several other species are Monogaga (Côte d’Ivoire). Thèse, département used for house building so that the disappearance did Hommes Natures Sociétés, MNHN, Paris, 233 p. not worry almost anyone. The non-use of the studied plant in some other domains such as medicine, food, Adou Yao, C. Y., Aké-Assi, E. and Ipou Ipou, J. (2010). Proposition d’inscription de Monanthotaxis capea crafts, exposed the taxon to a disappearance if no (Annonaceae) de Côte d’Ivoire sur la Liste Rouge de one takes precautions to cultivate it elsewhere (eg l’UICN. In: van der Burgt X., van der Maesen J. and village). Indeed, when people use the species, they Onana J.-M. (eds), Systématique et Conservation des develop strategies and practices to safeguard them. Plantes Africaines. 445–449. Royal Botanic Gardens, This was, for instance, the case of Abbey people who Kew. preserved a few individuals of Monanthotaxis capea Adou Yao, C. Y., Denguéadhé, K. T. S., Kouamé, D. and in the region of Agboville (Adou Yao et al., 2010). N’Guessan, K. E. (2007). Diversité et distribution des The lack of knowledge and knowhow of the local ligneux dans le Sud du Parc National de Taï (PNT), people about the species could be a source of threat. Côte d’Ivoire. AGRON. AFR. XIX (2): 113-122 It can therefore be said that Nuxia congesta is endangered in Côte d'Ivoire due to its very small Aké-Assi, L. (1998). Espèces rares et en voie d’extinction de la flore de la Côte d’Ivoire. Monographie Syst. Bot. population and human activities on it. Missouri Botanical Garden. 25: 461 – 463. Conclusion: At the end of this study, we can say that Aké-Assi, L. (2001). Flore de la Côte d’Ivoire 1 : Catalogue Nuxia congesta R. Br. ex Fresen. (Buddlejaceae) is systématique, biogéographie et écologie. reported in five sites among which only three (3) Conservatoire et Jardin Botanique, Genève, Suisse, located in the ‘Sub-préfecture’ of Kossou in the 396 p. Centre-West of Côte d’Ivoire still host the species. Aké-Assi, L. (2002). Flore de la Côte d’Ivoire 2 : Catalogue Although it grows preferentially around 1,500 m a.s.l., systématique, biogéographie et écologie. it could be found at lower elevations (152 – 240 m Conservatoire et jardin Botanique, Genève, Suisse, a.s.l.) in West African forests (Ghana and Côte 401 p. d’Ivoire) and in South Africa (152 m a.s.l.). Among Bouquet, A. and Debray, M. (1974). Plantes médicinales de the threats to this species that was already rare in the la Côte d’Ivoire. Mémoires O.R.S.T.O.M., 32. Paris, Ivorian vegetations, the higher population density in 232 p. the regions of occurrence, the slash, and the burn farming activities on upper slopes and summits of the Brooks, D.M., Pandov., L., Ocminp, A. and Tejadar., J. mountains seemed very crucial especially when (2001). Resource separation in a Napo-Amazonian gamebird community. In: Brooks D.M., and Gonzalez people use bushfire techniques. The intrinsic F. (eds). Biology and conservation of cracids in the characteristics of N. congesta (lack of fruits and New Millenium. Misc. Publ. 2, 213–225. Houston seeds, and seedlings) also contributed to threaten its Museum of Natural Sciences, Houston, Texas. survival. The mining activities on the largest site of occurrence are currently the greatest threat to this CDB (2001). Hand Book on Biological Diversity. UNEP, species that deserves the status of endangered (EN) Québec Canada. species on the IUCN Red List for the Ivorian flora. Demel Teketay. (1997). Seedling population and Protection activities are to be undertaken to preserve regeneration of woody species in dry Afromontane its natural habitat. forests of Ethiopia. Forest Ecology and Management 98: 149-165. ACKNOWLEDGEMENTS Eggeling, W.J. and Dale, I.R. (1951). The Indigenous Trees We would like to show our sincere gratitude to the of the Uganda Protectorate, 2nd edition Government managers of Cluff Gold who permitted us to conduct Printer, Entebbe: 166, as Lachnopylis congesta (R Br.) surveys in their area and who also helped fund part CA Sm. of this study. We also thank the technicians and the

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GBIF Data Portal (2010). www.gbif.net. 2010-11-10. GBIF- Mibey, R. K., Kokwaro, J.O. and Mukunya, D.N. (1996). Sweden 10 records; Herbarium of the University of Four new species and some new records of Aarhus 3 records; Missouri Botanical Garden 55 Meliolaceous fungi from Kenya. Mycotaxon 57: 87-95. records; National History Museum, Vienna-Herbarium W 1 record; Royal Botanic Garden Edinburgh 2 Myers, N. ., Mittermeier, R. A., Mittermeier, C. G., Da records; Royal Botanic Gardens, Kew 21 records. Fonseca, G. A. B. and Kent, J. (2000). Biodiversity hotspots for conservation priorities. Nature 403: 853 - Geldenhuys, C.J. (1992). The use of diameters distribution 858. in Suistained-Use Management of Forests: Example from Southern Africa. In: Pearce G.D. and Gumbo D.J. N’Da, D. H., Adou Yao, C. Y., N’Guessan, K. E., Koné, M. (eds), The Ecology and Management of Indigenous and Sagne, Y. C. (2008). Analyse de la diversité Forests in Southern Africa. 154-167. Proceedings of floristique du parc national de la Marahoué, Centre- an International Symposium, Victoria Falls, Zimbabwe, Ouest de la Côte d’Ivoire. Afrique SCIENCE 04(3) 552 27-29 July 1992. Zimbabwe Forestry Commission and - 579. SAREC, Harare. Palmer, E. and Pitman, N. (1972). Trees of Southern Africa. vol. II. A.A. BalKema Cape Town. Golding, J.S. (2002). Regional Overview. In: Golding J.S. (eds) Southern African Plant Red Data Lists – Poorter, L., Bongers F., Kouamé, F. N. and Hawthorne, W. Southern African Botanical Diversity Network Report D. (2004). Biodiversity of west African forests: An 14: 2-7, SABONET, Pretoria. ecological Atlas of Woody Plant Species. CABI Govaerts, R. (2006). World Checklist of Stilbaceae. The Publishing, London, UK. Board of Trustees of the Royal Botanic Gardens, Kew. Sokpon, N. and Biaou, S. H. (2002). The use of diameter Published on the Internet; http://www.kew.org/wcsp/. distributions in sustained-use management of remnant th Retrieved November 10 2010. forests in Benin: case of Bassila forest reserve in North Guillaumet, J. L. and Adjanohoun, E. (1971). La végétation Benin. For. Ecol. Manage. 161: 13 - 25. de Côte d’Ivoire. In : Avenard J.M., Eldin E., Girard G., Tamrat Bekele (1994). Studies on Remnant Afromontane Sircoulon J., Touchebeuf P., Guillaumet J. L., Forests on the Central Plateau of Shewa, Ethiopia. Adjanohoun E. and Perraud A. (eds). Le milieu naturel PhD Dissertation, Uppsala University, Uppsala, de la Côte d’Ivoire. 159-263. O.R.S.T.O.M., Paris. Sweden. Hawthorne, W.D. (1996). Holes and the sums of parts in UICN (2001). Catégories et critères de l’UICN pour la liste Ghanian forest: regeneration, scale and sustainable rouge: Version 3.1. IUCN, Conservation Monitoring use. Proceedings of the royal Soc. Edinburgh 104B: Centre, Cambridge, UK. 75-176. UICN (2003). Lignes Directrices pour l’Application, au Hawthorne, W.D. (1995). Ecological profiles of Ghanaian Niveau Régional, des Critères de l’UICN pour la Liste forest trees. Tropical Forestry Paper 29. Oxford Rouge. UICN, Conservation Monitoring Centre, Forestry Institute. Cambridge, UK. Keay, R. W. J. and Hepper, F. N. (1954-1972). Flora of Watt, J. M. A. and Breyer-Brandwijk, M. G. (1962). The nd West tropical Africa. 2 edition. Millbink, London. Vol. I medicinal and poisonous plants of Southern and (828 p), Vol. II (544 p), Vol. III (574 p). Eastern Africa. Edinburgh: E & S Livingstone. Kouamé, N. F. (1998). Influence de l'exploitation forestière White, F. (1983). The vegetation of Africa, a descriptive sur la végétation et la flore de la foret classée du Haut memoir to accompany the UNESCO/AETFAT/UNSO. Sassandra (Centre-ouest de la Cote d'Ivoire). Thèse Nat. Resources res. 20: 1-356. de Doctorat 3ème cycle. Université de cocody Abidjan. 228 p.

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