Hindawi International Journal of Forestry Research Volume 2021, Article ID 5582461, 19 pages https://doi.org/10.1155/2021/5582461 Research Article Occurrence of Citropsis articulata in Tropical Forests in Uganda: Implication for Ex Situ Conservation Rapheal Wangalwa ,1,2 Eunice Apio Olet,1,2 Grace Kagoro-Rugunda,1 Casim Umba Tolo,1,2 Patrick E. Ogwang,2,3 and Bernard Barasa4 1Department of Biology, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda 2Pharm-Biotechnology and Traditional Medicine Centre, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda 3Department of Pharmacy, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda 4Department of Geography and Social Studies, Kyambogo University, P.O. Box 1, Kyambogo, Uganda Correspondence should be addressed to Rapheal Wangalwa; [email protected] Received 8 January 2021; Revised 28 February 2021; Accepted 4 March 2021; Published 25 March 2021 Academic Editor: Anna Z´r´obek-Sokolnik Copyright © 2021 Rapheal Wangalwa et al. ,is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Citropsis articulata is a medicinal plant that is increasingly threatened by unsustainable methods of harvesting and habitat deg- radation. Owing to the fact that this plant species is highly utilized for herbal medicine and is currently restricted to a few forest reserves in Uganda, this has significant implications for ex situ conservation. ,erefore, the aim of this study was to assess how physiographical factors influence the occurrence and distribution of C. articulata in the three forest reserves in Uganda, namely, Budongo, Mabira, and Kibale National Park. ,e study was carried out in 15 compartmental sites in each of the three forests. In each compartmental site, 4 plots of 60 m × 60 m were systematically established, and within each plot, 4 subplots each of size 20 m × 20 m were randomly setup. A total of 240 subplots were assessed for occurrence of Citropsis articulata in each forest. ,e results indicated a significant (p < 0:05) variation in the density of C. articulata with the highest recorded in Kibale National Park. Citropsis articulata generally occurred at moderate altitudinal landscapes (overall elevation = 1200.0 ± 20.73 m) with soils that are moderately acidic (overall pH = 5.7 ± 0.10), low in salinity (overall salinity = 84.0 ± 3.84 mg/l), and moderate levels of macro- and micronutrients. Citropsis articulata was generally associated with plant communities dominated by canopy tree species of genera such as Chryosphyllum, Celtis, Markhamia, Cynometra, Lasiodiscus, Trilepisium, Funtumia, and Diospyros, thus suggesting that C. articulata is a shade-tolerant species. Establishing the ecological requirements of this plant species among other things informs the potential for ex situ production of this plant. ,is will not only provide alternative sources of plant harvest but also go a long way in relieving the current harvest pressures exerted on the conserved wild populations of this plant species. 1. Introduction taller [1, 3]. ,is plant species is well known for its aph- rodisiac properties, and recent studies have proven its Citropsis articulata (Willd. ex Spreng) Swingle & Kellerm, antiplasmodial potential too [4, 5]. Unfortunately, the plant family Rutaceae, is commonly known as the African cherry part used for its medicinal purpose is the root and thus the orange. ,e plant species is native to West, Central, and East most harvested, and this could endanger its existence. In African countries including Cameroon, Central African Uganda, the species is mainly restricted to the understory of Republic, Congo, Gabon, Ghana, Guinea, Ivory Coast, moist evergreen forests located mainly in the Albertine rift Liberia, Nigeria, Sierra Leone, Sudan, Tanzania, Togo, and including Budongo Central Forest Reserve and Kibale Na- Uganda [1, 2]. Citropsis articulata is usually a shrub or small tional Park but also reported in the Mabira Central Forest tree, ranging from 2.5 to 5 m in height but sporadically much Reserve in Central Uganda. 2 International Journal of Forestry Research ,e fact that just a handful of forest reserves in Uganda ,erefore, the aim of this study was to investigate how act as the natural habitats of C. articulata could have far- physiographical (location, topography, and soil) factors reaching implications. In Uganda, 61.4% of forest reserves influence the occurrence and distribution of C. articulata in are managed by the National Forestry Authority (NFA), the three forests of Uganda, namely, Budongo, Mabira, and whereas 33.6% are managed by Uganda Wildlife Authority Kibale National Park. ,e specific objectives were to (1) (UWA), while 4.7% are jointly managed by NFA and UWA establish whether geolocation and forest management have and 0.3% by local governments [6]. Under the manage- implications on the occurrence and distribution of ment of National Forestry Authority, Central Forest Re- C. articulata, (2) determine whether soil chemical param- serves (CFRs) were set aside to provide forest products, eters have an effect on the occurrence of C. articulata in the recreation, protect and conserve biodiversity, stabilize three tropical forests of Uganda, and (3) determine the plant soils, and improve climate and protect water catchments, species assemblages that co-occur with C. articulata in the among others [6, 7]; this includes the likes of Budongo and three forests of Uganda. ,e findings of this study have Mabira Central Forest Reserves. Despite the measures put extensive implications: first, any indications of habitat in place by NFA to protect central forest reserves as specificity and preferences by C. articulata would mean that stipulated in the forestry policy, prohibited activities such success of any offsite production would entail provision of as illegal logging, charcoal production, and illicit harvest such conditions to suit its production. Secondly, significant of nontimber forest products (NFTPs) still persist in most variation in the occurrence of C. articulata in the three central forest reserves. ,is in part is attributable to the stipulated forests would indicate that location and man- management weaknesses such as weak law enforcement agement strategies may have an impact on occurrence of resulting from limited staffing [6, 8]. ,e predicament is C. articulata. ,erefore, there is need for designing and further compounded by the location of some forests near implimentatng suitable and continuous monitoring pro- metropolitan areas in addition to having settlement en- grams to protect and conserve C. articulata and possibly claves within the forest reserve boundaries; case in point is curb any anthropogenic activities leading its vulnerability. Mabira Central Forest Reserve. On the other hand, Kibale Forest currently managed by UWA was gazetted as a 2. Materials and Methods National Park in 1993, at which point management em- phasized exclusive conservation with no human use 2.1. Study Area. Uganda lies across the equator in Eastern allowed except for research and tourism [9]. We therefore Africa between the latitudes 4.5°N to 1.5°S and longitudes hypothesize that these differences in forest management 29.5°E to 35°E (Figure 1), at an average altitude of 1,100 could impact on the occurrence of C. articulata in the meters above sea level. ,is study was conducted in three three forest reserves. geolocations, i.e., Mabira Central Forest Reserve, Budongo Citropsis articulata is listed among the vulnerable species Central Forest Reserve, and Kibale National Park (Figure 1). of Uganda according to the International Union for Con- ,e three geolocations were selected based on the following servation of Nature (IUCN) red list for Uganda [10]. Besides, criteria: (1) the presence of Citropsis articulata, (2) man- Okeowo [11] noted that C. articulata is disappearing in agement status, (3) the degree of human activities in the area, Mabira Central Forest Reserve at an alarming rate. ,is was providing a possibility to determine the impact of these attributed to overexploitation and unsustainable methods of activities, and (4) agroecological zone (AEZ) classification. harvesting, owing to increased demand and commercial ,e three geolocations are encircled by varying agro- value for its roots [8]. Additionally, factors such as envi- ecological zones. ,e zones are characterized by different ronmental degradation and climate change may further farming systems determined by soil types, climate, land- increase the vulnerability of this plant species. ,is therefore forms, and socioeconomic and cultural factors [20]. calls for the need to develop and enhance other conservation approaches such as ex situ conservation through offsite production (e.g., cultivation and or domestication). How- 2.1.1. Mabira Central Forest Reserve (MCFR). Gazetted in ever, the success of any ex situ conservation program, 1932, Mabira Central Forest Reserve (MCFR) lies partly in specifically offsite production, requires understanding the Buikwe, Mukono, and Kayunga districts. It occupies an area ecological conditions and requirements of the plant in of 306 km2 and is situated between latitudes 0°22′N to 0°36′N question in this case C. articulata. For instance, species- and longitudes 32°50′E to 33°07′E with an altitudinal range specific growth and survival responses to resources partic- of 1073–1348 m above sea level (Figure 2). ,e landscape of ularly physiographical factors play a key role in determining the forest is generally characterized by gently undulating the success of species offsite production. ,e influence of soil flat-topped hills to wide shallow valleys occupied by swamps factors on plant growth has been extensively studied (e.g., [21, 22]. ,e flat-topped hills are remnants of the earlier [12–16]). However, this information does not provide local peneplain uplifted by tectonic movements which lowered evidence on how soil conditions impact on the occurrence of the land south of MCFR and were filled up by river water C. articulata in Ugandan forests.