Scholars Academic Journal of Biosciences Abbreviated Key Title: Sch Acad J Biosci ISSN 2347-9515 (Print) | ISSN 2321-6883 (Online) Journal homepage: https://saspublishers.com Biodiversity, Conservation Biology and Botany Using Endemic Rubiaceae of the Lower Guinea Domain to Locate the Priority Sites for Conservation in Cameroon Hermann Taedoumg1*, Louis-Paul Roger Kabelong Banoho1, Nicole Liliane Maffo Maffo1 1Department of Plant Biology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon DOI: 10.36347/sajb.2021.v09i03.003 | Received: 07.02.2021 | Accepted: 15.03.2021 | Published: 20.03.2021 *Corresponding author: Hermann Taedoumg Abstract Original Research Article From herbarium specimens and literature review of Rubiaceae, we established a list of 387 endemic taxa (species, subspecies and varieties) from Lower Guinea Domain, with 288 present in Cameroon. Two hundred and three taxa having specimens from BM, BR, BRLU, P, K, MO, SCA, WAG, and YA were taken into account in our analyses. The specific diversity was determined by counting the number of species per grid square with Arc view 3.3. The distribution maps are obtained by projecting the coordinates of collecting sites on map of Cameroon. It appears that there are several hotspots of Rubiaceae in Cameroun. Four principal zones are distinguished: Mount Cameroon area (86 taxa), Kupe and Bakossi area (66 taxa), Bipindi-Akom II area (68 taxa), and Yaounde and its surroundings (28 taxa). The most significant factor to explain the endemism and the specific richness of Rubiaceae in Cameroun is altitude. The high precipitation and the continental gradient also play an important role in explaining this richness. The confinement of endemic Rubiaceae in Atlantic forests seems to be an argument in favor of this hypothesis. The area around Yaoundé and the massifs around Bipindi have no conservation status. Both areas are under permanent threat from logging and slash-and-burn agriculture and from ever-increasing population pressures. There is an urgent need for conservation measures to be taken to protect these forests, the importance of which is highlighted in this study. Yaounde is a large urban agglomeration and the easily accessible hills could be, in the medium term, financially viable through ecotourism. Keywords: Rubiaceae, Distribution, Specific richness, Endemism, Lower Guinea Domain, Cameroon. Copyright © 2021 The Author(s): This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY-NC 4.0) which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited. NTRODUCTION activities (industrial plantations, industrial logging) and I galloping demography. The conclusions of the 1992 United Nations Conference in Rio de Janeiro state that biodiversity Tropical forest conservation is currently a refers to the variability of living organisms from all major issue; any research to protect significant areas sources, including terrestrial, marine and aquatic from deforestation is justified. Conservation requires an ecosystems and the ecological complexes of which they understanding of the historical processes of vegetation are part. Biodiversity is therefore the basis for the proper establishment and evolution, as the maintenance of functioning of ecosystems that provide essential goods specific and genetic diversity certainly depends on the and services for human subsistence. Natural resources latter factors. The location of forest refuges is an have always been used to meet the primary needs of important tool in this regard. The location of forest communities, not only to provide food, fuelwood, and refuges is an important tool in this regard. Indeed, these building materials, but also to enable the economic refuges constitute areas where lowland and mountain (small- and large-scale), social, and cultural forests have been maintained during past climatic development of peoples [1]. Areas teeming with rich changes, in particular, the last ice ages (18,000 years biodiversity generally tend to blend in with those with ago); this has favored the development of a certain some of the world's poorest populations [2]. With an area endemism [4]. Studies conducted in Africa on Begonia of over 2,000,000 km2, the forests of Central Africa is, [5-7] have shown that these refuges constitute sites with after the Amazon, the second largest forest on our planet a very high specific richness and endemism rate. The [3]. The forests present in Cameroon, Equatorial Guinea development of a method based on the study of indicator and Gabon constitute about 20% of this large forest species allowing the location of sites with high complex. Although it represents large areas, this forest biodiversity without carrying out exhaustive inventories resource is now more threatened than ever by human would be welcome. Citation: Hermann Taedoumg et al, Using Endemic Rubiaceae of the Lower Guinea Domain to Locate the Priority Sites for 68 Conservation in Cameroon. Sch Acad J Biosci, 2021 Mar 9(3): 68-83. Hermann Taedoumg et al., Sch Acad J Biosci, Mar, 2021; 9(3): 68-83 Rubiaceae family includes about 650 genera The LGD is the region that encompasses and nearly 13,100 species [8], placing it, after the southeastern Nigeria, Equatorial Guinea, Gabon, Congo, Asteraceae, Orchidaceae, and Fabaceae, among the the enclave of Cabinda, the islands of the Gulf of Guinea largest families of Angiosperms. The most famous and (Bioko, Annobon, Sao Tome and Principe), and the economically valuable genus of the family is Coffea L. southern part of Cameroon [12]. Coffee is the most traded product in the world after oil [8]. Other economically important Rubiaceae include MATERIAL ET METHODS Cinchona officinalis L. (quinine), Pausinystalia johimbe This study is based on the examination of (K. Schum.) Pierre (yohimbine, aphrodisiac), Nauclea herbarium specimens available at the Yaoundé National diderrichii (De Wild. & T. Durand) Merr. (Bilinga, Herbarium (YA), the Limbe Botanical Garden (SCA) timber), species of Genipa L. (genipapo, beverage), herbarium as well as those collected during our field Calycophyllum DC. (lumber) and Gardenia J. Ellis trips. In addition, samples from BM, BR, BRLU, K, P, (perfume). The family also contains some of the most and WAG were also included, abbreviations follow beautiful tropical ornamental plants (Ixora L., Gardenia Holmgren et al., [13]. In total 2364 herbaria specimens L., Mussaenda L.). Rubiaceae is a cosmopolitan family; were considered in this work. it is a tree, shrub, vine or herbaceous plant widely distributed in tropical, subtropical and temperate Data used to set the list of endemic Rubiaceae regions. Most representatives of the family are located in of the LGD were obtained from several sources: (i) the tropical and subtropical regions. Rubiaceae are present "World Checklist" of Rubiaceae available on the Kew in all vegetation strata and can sometimes represent up to Botanical Garden Herbarium website; (ii) examination 50% of the total understory biomass, thus playing an of herbarium samples collected in Cameroon and important ecological role at all levels [9]. The Rubiaceae available at BM, BR, BRLU, K, MO, P, SCA, WAG, and of temperate regions are exclusively herbaceous and the YA; (iii) the bibliography on the Rubiaceae family in number of species in the family is limited. This vast and Africa and Cameroon; (iv) the Rubiaceae section of the taxonomically complex family has aroused a growing Mount Cameroon Plant Checklists [14], Mount Oku interest in the last few decades, initiated by the [15], Mount Kupe [16] and Bali Nguemba [17]. publication of "Tropical Woody Rubiaceae" [10]. This pioneering text gives an overview of the characters Two hundred and three taxa are included in the (mainly morphological and anatomical, but also analyses for Cameroon, as they have samples present in biological and chorological) of the tropical woody the herbaria mentioned above. It should be noted Rubiaceae, proposes a classification of the group, draws however, that only samples from YA and SCA were up an inventory of the gaps in knowledge of the family at examined and databased, i.e. 1051 specimens. The the time and suggests avenues for future taxonomic habitats of each species where were collected. A species research. reported several times and exclusively in the same environment is said to be exclusive of this habitat. The The present contribution is part of the research information comes from the herbarium sheets and from on Rubiaceae and Orchidaceae undertaken to study the our field observations. The distribution maps were diversity and distribution of Rubiaceae endemic to the obtained by georeferencing the collection sites and Guinean-Congolian region in Cameroon [11]. The exporting them to Arc View 3.3. Specimens with lacking objective is to locate sites with high diversity and geographic coordinates (on the herbarium sheets), are endemism rates for Rubiaceae. These sites can therefore georeferenced from gazetter 60 [18]. Species richness be prioritized for protection in order to conserve reflects the number of taxa present in a given grid cell. biodiversity as effectively as possible. This localization Cameroon was divided into grids of different sizes (0.5 is, in our opinion, the first step in the conservation effort. degree and 1 degree square). These grids are established with "Mila Utilities 3.2" and "Geoprocessing" More specifically, the objectives of this paper extensions of Arc View 3.3. Calculation of the number of are (i) to constitute a database of the Rubiaceae of the species and genera present in each grid was done with LGD including all the taxa of this zone, using the the extension "Counts Points in Polygon". available herbarium specimens, the geographical distribution, the ecological data (altitude, habitat), (ii) to RESULTS establish a general distribution map of the species ENDEMISM AND SPECIFIC RICHNESS OF THE present in Cameroon and finally (iii) to recommend sites LOWER GUINEA DOMAIN that can be prioritized in conservation actions in Three hundred and eighty-two taxa (species, Cameroon.