The majority of the tree species from the 32 taxa studied have been evaluated globally on IUCN as LC (Table 2). Overall, about 97% of the taxa were evaluated as threatened (41% as Endangered, 31% as critically endangered, 24% as Vulnerable, and 4% as Least Concerned) (Fig. 4). These results highlight the general lack of information on the conservation status of most Nigerian flora. Nonetheless, this lack of studies on Nigeria flora resulting in knowledge gaps could be due to a lack of funding for basic baseline research on specific species (Bello et al. 2023). Therefore, further studies are urgently needed to identify threatened species and develop proper conservation strategies as highlighted below.
Table 2
Regional and Global IUCN Status of the species studied
S/N
|
Species
|
Family
|
Local Red listing
|
Global IUCN assessment
|
1.
|
Afzelia Africana Sm.
|
Fabaceae
|
CR = B1ab (ii, iii, v) + 2ab (ii, iii, v); C2a(ii); D
|
VU
|
2.
|
Anogeissus leiocarpa (Hochst. ex Hutch. & Dalziel)
|
Combretaceae
|
EN = B2ab (ii, iii, v)
|
LC
|
3.
|
Bombax costatum Pellegr. & Vuillet.
|
Bombacaceae
|
EN = B2ab (ii, iii,)
|
LC
|
4.
|
Boswellia dalzielii Hutch.
|
Burseraceae
|
CR = B1ab (i, ii,iii) + B2ab (i,ii,iii,iv)
|
NE
|
5.
|
Burkea Africana Hook.
|
Fabaceae
|
VU = B2ab (ii, iii, v)
|
LC
|
6.
|
Ceiba pentandra (L.) Gaertn.
|
Malvaceae
|
EN = Endangered B2ab (i,ii,iii,iv)
|
LC
|
7.
|
Combretum molle R.Br. ex G.Don
|
Combretaceae
|
VU = B2ab (ii, iii, v)
|
LC
|
8.
|
Crossopteryx febrifuga (Afzel. ex G.Don) Benth.
|
Rubiaceae
|
VU = B1ab (ii, iii, v) + 2ab (ii, iii, v)
|
|
9.
|
Daniellia oliveri (Rolfe) Hutch. & Dalziel
|
Fabaceae
|
EN = Endangered B1ab (i, ii, iii, iv)
|
NE
|
10.
|
Detarium microcarpum Guill. & Perr
|
Fabaceae
|
CR = B1ab (ii, iii, v) + 2ab(ii, iii, v); D
|
LC
|
11.
|
Diospyros mespiliformis Hochst. ex A.DC.
|
Ebenaceae
|
EN = B1ab (ii, iii, v) + C2ab (i); D
|
LC
|
12.
|
Entada africana Guill. & Perr.
|
Fabaceae
|
LC = Least Concern
|
LC
|
13.
|
Erythrina senegalensis Schumach. & Thonn.
|
Fabaceae
|
Vulnerable = VU = B2ab (ii,iii,v)
|
LC
|
14.
|
Erythrophleum suaveolens (Guill. & Perr.) Brenan
|
Fabaceae
|
VU = B2ab (ii,iii,v)
|
LC
|
15.
|
Faurea rochetiana (A.Rich.) Chiov. ex Pic.Serm.
|
Proteaceae
|
CR = B1ab (iii) + 2ab (iii) + B2a (iii); D
|
LC
|
16.
|
Hymenocardia acida Tul.
|
Phyllanthaceae
|
EN = B2ab (ii,iii,v)
|
LC
|
17.
|
Isoberlinia doka Craib & Stapf
|
Fabaceae
|
Vulnerable, B2ab (ii,iii,v)
|
LC
|
18.
|
Khaya senegalensis
A. Juss.
|
Meliaceae
|
CR = B2ab (ii,v)
|
VU
|
19.
|
Kigelia africana (Lam.) Benth.
|
Bignoniaceae
|
EN = Endangered B2ab (ii, iii, v)
|
LC
|
20.
|
Lannea acida A.Rich
|
Anacardiaceae
|
Vulnerable Endangered B1ab (ii, iii, v) + 2ab (ii, iii, v)
|
LC
|
21.
|
Lophira lanceolata Tiegh. ex Keay.
|
Ochnaceae
|
EN = Endangered B2ab (ii, iii, v)
|
LC
|
22.
|
Parkia biglobosa (Jacq.) R.Br. ex G. Don
|
Fabaceae
|
VU = Vulnerable B2ab (ii, iii, v)
|
LC
|
23.
|
Prosopis africana (Guill. & Perr.) Taub.
|
Fabaceae
|
EN = Endangered B1ab (ii, iii, v) + 2ab (ii, iii, v)
|
LC
|
24.
|
Pseudocedrela kotschyi (Schweinf.) Harms
|
Meliaceae
|
VU = B2ab (ii, iii, v)
|
|
25.
|
Pterocarpus erinaceus Poir
|
Fabaceae
|
CR = Critically Endangered, B1ab (ii, ii, iv) + 2ab(ii, iii, v); C2a(v);D
|
EN
|
26.
|
Securidaca longepedunculata
Fresen
|
Polygalaceae
|
CR = Critically Endangered, B1ab (ii, ii, iv);D1
|
LC
|
27.
|
Sterculia setigera Delile
|
Malvaceae
|
CR = Critically Endangered, B1ab (ii, ii, v)
|
LC
|
28.
|
Terminalia habeensis (Aubrév. ex Keay) Gere & Boatwr
|
Combretaceae
|
CR = Critically Endangered CRB1 + 2ab (iii)
|
EN
|
29.
|
Terminalia macroptera Guill. & Perr.
|
Combretaceae
|
EN = B1ab (ii, iii, v) + C2ab (i); D
|
LC
|
30.
|
Terminalia schimperiana
Hochst
|
Combretaceae
|
EN = Endangered B2ab (ii, iii, v)
|
Not evaluated
|
31.
|
Uapaca togoensis Pax
|
Phyllanthaceae
|
LC = Least Concern
|
|
32.
|
Vitellaria paradoxa C.F.Gaertn.
|
Sapotaceae
|
EN = Endangered, B2ab (ii, ii, v)
|
VU
|
Description of the Taxa studied – IUCN Red List Assessments
Afzelia africana Sm. (Fabaceae)
Common name: African mahogany
Local names: Kààwóó (Hausa), Bantaje (Fulfulde)
Afzelia africana is widespread from West Africa to East Africa, including Sudan, Uganda, and Congo (Ecocrop 2018). In Nigeria, Afzelia africana is endemic in the wooded savanna zone of the country where, dense dry forests, and dense semi-deciduous forests are in moister areas. The tree can grow up to 10-18 m in savanna. It is tap-rooted but also develops secondary roots that explore the first centimeters of the soil. The trunk has small unequal buttresses at its base. The trunk is straight, cylindrical, and branchless up to 20 m high and can reach 1-1.8 m in diameter above buttresses. The bark is 2 cm thick, scaly, very aromatic, and grey to dark brown. The crown is large, and spreading. Its shape (flat or rounded) depends on age and growing conditions (Henning 2012).
This species was known to be widely distributed in the moist savanna areas of the country. This area is threatened by grazing, farming, and human population. A. africana is under several threats, most especially over-harvesting of the leaves for fodder for livestock. This species is the most sought-after by the Fulani herders in the country (Nodza et al. 2022a). The branches are constantly looped by the herders to feed their livestock (Ouachinou et al. 2018). The most stringent and persistent conservation threat to the species is the intensive logging of the species for timber, used by the international market (Hills 2020). This has decimated the population of the species from the previous habitats that they were once abundant. The extent of occurrence (EOO) of A. africana is estimated to be 90 km2 whereas its area of occupancy (AOO) is estimated to be 2800 km2. In most of the localities visited even inside the protected areas, the population size of the species is estimated to be < 50 mature individuals and is decreasing. This species has a slow regeneration rate which is being exacerbated by climate change (Balima et al. 2018; Boakye et al. 2023). Globally this species has previously been assessed as Vulnerable (VU) by the IUCN (Hills 2020). Based on the above criteria, we assessed this species as Critically Endangered, (CR) for the country.
CR- B1ab (ii, iii, v) +2ab (ii, iii, v); C2a(ii); D
Recommended conservation actions needed: The recommended conservation action is the collection and growing of seedlings as agroforestry trees. Also the inclusion of A. africana in Appendix I of the Convention on International Trade in endangered species of wild Fauna and Flora (CITES) to restrict international trade in its wood is highly recommended.
Anogeissus leiocarpa (Hochst. ex Hutch. & Dalziel)
Family: Combretaceae
Common name: African birch
Local names: Márkéé (Hausa), kojo-li (Fulfulde)
Anogeissus leiocarpa is a deciduous tree that grows up to a height of 15-18(-30) m (Klaus et al. 2005). The species is found from the driest savanna to the wetter forest borders, in wooded grassland and bushland, and gallery forests (Ouédraogo et al. 2013) in tropical Africa. In Nigeria, A. leiocarpahas a wide range of distribution across the various grades of savanna in the country. The species has vast ethnobotanical and medicinal applications. The bark, leaves, and roots are used traditionally for tanning hides to leather (Mann et al. 2008). Again ash of the burnt wood is used in northern Nigeria as a dehairing agent in the preparation of skins for the tanning bath (Burkhil 1985-2004; Reuben et al. 2013). Traditionally this species is used against yellow fever, jaundice, and different kinds of hepatitis, common cold, and headache (Burkhil 2004).
This species is threatened by the recent incessant logging of wood for timber and charcoal making. Verbal discussion with the local timber dealers, experience foresters and some botanists revealed that A. leiocarpa is a hardwood, and timber from this species is resistant to termite infestation making it a good product for marketing. Additional noticeable threats recorded were cutting the trees for making farming implements, household utensils, and making charcoal. However, logging of the species coupled with harvesting for ethnobotanical uses has put the species of A. leiocarpa on the verge of local extinction. This has reduced the extent of occurrence (EOO) of A. leiocarpa is estimated to be 100 km2, and the area of occupancy (AOO) at the estimate of 4000 km2. Despite the suggestion from previous studies on the need to actively or effectively prioritize the conservation measures toward A. leiocarpa, especially in their natural stands to guarantee the species' survival, (Ouedraogo et al. 2013). Yet the species have not globally been evaluated on the IUCN conservation assessment. Based on the above, Anogeissus leiocarpa is thus assessed as Endangered (EN).
EN- B2ab (ii, iii, v)
Recommended conservation actions: We recommend further monitoring and research activities on the species to better understand the population trends of the species in Nigeria
Bombax costatum Pellegr. & Vuillet.
Family: Bombacaceae
Common name: Kapok
Local names: gúrijíyaá (Hausa), kuruhi (Fulfulde)
Bombax costatum is a deciduous tree that usually grows 10-25m high by 1 m girth, straight trunk slightly thickened basally, thick corky bark, and spiny when young ( Hutchinson and Dalziel 1927-1954; Burkhil 2004; Keay et al. 1989). Bombax costatum is an endemic savanna species distributed in savanna zones in Western Africa from Chad to Mauritania (Assogba et al.2018). Bombax costatum is one of the most widely used and important wild plant species, as it is extensively used for food and medicinal purposes as well as for handicrafts (Zerbo et al. 2022). The calyx is sold on local markets and hence constitutes an additional source of income in rural communities (Ouedraogo et al. 2014; Assogba et al. 2018). B. costatum is under serious threat as a result of the degradation of natural stands through several anthropogenic activities (Assogba et al. 2018). These activities include the harvesting of its flowers in large quantities for domestic and commercial use as a vegetable, especially in north-central Nigeria (precisely Benue, Nasarawa, and Plateau states) part of the country. And excessive grazing of the seeds by cattle. This harvesting of the fruits is capable of impeding fructification which is an important aspect of plant biomass production (Assogba et al. 2018). Bombax costatum has recently been threatened by logging of the species for timber in most parts of the NSZ, especially Bauchi, Plateau, and Nasarawa. This threat has been worsened by its poor natural regeneration (Coulibaly et al. 2023).
Overall, these threats have narrowed the extent of occurrence of the species as this species is now restricted to wetter savanna (Guinea savanna) areas of the study area. Despite the threats confronting this species. Yet B. costatum has been evaluated globally as the least concern (LC) in the IUCN Red List of Endangered Species (IUCN SSC/BGCI 2019). The extent of occurrence (EOO) of B. costatum is estimated to be 2000 km2 whereas its area of occupancy (AOO) is estimated to be 6000 km2. Hence B. costatum is thus assessed as Endangered.
EN- B2ab (ii, iii,)
Recommended conservation actions: Improving the genetic diversity of Bombax costatum might lead to the loss of inherent genes responsible for the domestication of the species (Assogba et al.2018). Therefore, further monitoring and research activities are recommended to better understand the species’ population trends in Nigeria.
Boswellia dalzielii Hutch.
Family: Burseraceae
Common name: frankincense tree
Local names: Árárráɓíí (Hausa), anndakehi (Fulfulde)
Boswellia dalzieliiis a tree to 13 m high characteristically pale papery bark with small white flowers (Burkhil 1985). The species is distributed in the Sahel-Sudanian savanna, from northern Cameroon to southern Mali, with populations concentrated in Nigeria, Cameroon, Benin, Togo, Ghana, and Burkina Faso (Sabo et al. 2021). The genus Boswellia is known for its production of a highly aromatic, terpenoid oleo-gum-resin, called frankincense, which has been widely used and traded around the world for centuries and is considered to be one of the oldest internationally traded commodities globally (Johnson et al. 2023). The resins extracted from Boswellia incense, are for industrial purposes, religious rituals, and ceremonies, as well as for yielding volatile oils, which are used in the perfumery industry (Sabo et al.2021; 2023), and spiritual paraphernalia. In Nigeria, B. dalzielii is very popular among the natives as a potential source of several traditional medicines. The stem bark is used for the management of venereal diseases, fever, leprosy, rheumatism, ulcers, pain, inflammation, gastrointestinal disorders, malaria, toothaches, sores, abscesses, mental disorders, yellow fever, asthma, wounds, and dysentery (Burkhil 2004). Despite these culminated uses, unfortunately, all members of the genus Boswellia are globally endangered as a result of overexploitation and overgrazing by livestock (Hamdiah et al. 2022), fire, land conversion for agriculture, improper or excessive harvesting of resin, and attacks by insects (Johnson et al. 2023). This species is threatened in Nigeria by overharvesting, agriculture expansion, excessive grazing, and climate change. B. dalzielli is scarce in most habitats, and the number of mature individuals is limited. Unfortunately, even the few mature individuals recorded are unabatedly and incessantly logged as timber at Yankari axis Bauchi state. This number of matured individuals observed from the populations was less than 20 individuals, and the species is not protected in Nigeria by any jurisdiction. Current anthropogenic pressure on natural habitats exacerbated by climate change is a serious threat confronting this species (Sabo et al. 2022). Based on the above, we therefore assessed Boswellia dalzielii as CR. This is incongruent with Bello et al. (2019) who also assessed this species as CR.
CR= B1ab (i, ii,iii) + B2ab (i,ii,iii,iv)
Recommended conservation actions: We recommended seed propagation of this species into mainstay agroforestry trees in the country
Burkea africana Hook.
Family: Fabaceae
Common names: Wild seringa (Eng.)
Local names: Báƙín màƙárfò (Hausa) kokobi (Fulfulde)
Burkea africana is deciduous, growing from 4 to 20 meters high, with a spreading crown, stout knotted branchlets, blackish corrugated bark, light silky foliage, and pendulous spikes of small creamy fragrant flowers crowded with the leaves at the ends of the branchlets (Van Wyk and Gericke 2000). Flowers are creamy white, fragrant, and in pendulous racemes of up to 300 mm in length and the bark is toxic, rich in alkaloids and tannins, and used for tanning leather (SANBI 2010). Burkea africana is widely distributed in West Tropical Africa up to northwestern Uganda and Cape Province (Burkhil 1985). It is a tree and grows primarily in the seasonally dry tropical biome, Plant of the World Online (POWO 2023). The tree has multipurpose uses as a source of tannins, fish poison, and antidotes and is used in various traditional and herbal preparations in large areas of sub-Saharan Africa (Burkhil 2004; Eboji et al. 2017; Namadina et al. 2020; Ezenyi et al. 2021). Burkea africana is threatened by deforestation, logging for timber and other domestic uses, harvesting of firewood, debarking for medicinal uses, population expansion, agricultural expansion, drought, and climate change, which often lead to habitat fragmentation (Maroyi 2012; Abubakar et al. 2018; Catarino et al. 2019; Nabaloum et al. 2022). However, B. africana has recently been assessed by Bello et al. (2019) for Katsina state in northwestern Nigeria as CR. And evaluated at the IUCN global level as LC (Hills 2019). The species has become rare as throughout the field surveyed, we recorded declining population size, the estimated extent of occurrence is > 20 000 km2 and the estimated area of occupancy is 1550 km2. Burkea africana is thus assessed as VU.
VU= B2ab (ii, iii, v)
Recommended Conservation actions: Burkea africana is one of the species that are difficult to grow (SANBI, 2010), hence further monitoring and research activities are recommended to better understand the species’ population trends in Nigeria.
Ceiba pentandra (L.) Gaertn.
Family: Malvaceae
Common name: kapok or silk-cotton tree
Local names: rimi (Hausa), bantaaje (Fulfulde)
Ceiba pentandra, popularly known as the white silk cotton belongs to the family Malvaceae. It is a native of India, Indonesia, and the US, but is now well distributed in the tropics (Burkhil, 1985). The matured tree can grow up to 56 m high and have huge buttresses (Hutchison and Dalziel 1954). This species has been reported to be the largest tree of the West Africa region and occurs throughout the region and well adapted to various habitats (Duvall 2011), and has diverse ethnobotanical applications. Ceiba pentandra has important uses which are as a source of fibre and timber. This use dates back to history when it was the most important source of kapok fiber; the floss derived from the inner fruit wall. This Kapok fibre is used for stuffing cushions, pillows, and mattresses, and for insulation, absorbent material, and tinder (Burkhil, 2004, Duvall, 2011).
Conversely, C. pentandra is under numerous threats, as throughout the distribution range of the species in Nigeria, people use its wood for house and canoe construction. However, this excessive harvesting of the tree for timber and non-timber forest products is a danger to the sustainability of the species (Zoma et al. 2022). The seed fibre is used as a substitute for cotton to fill blankets and pillows. The slow regeneration rate of the species is another concern that has posed significant threats to the sustainability of the species. Although C. pentandra has been assessed globally on the IUCN as least concern (LC) IUCN (2022). In the NSZ of Nigeria, the population size is decreasing, the estimated extent of occurrence is 15,000 km2 and the estimated area of occupancy is 250 km2. C. pentandra is thus assessed as EN.
EN= Endangered B2ab (i,ii,iii,iv)
Recommended conservation actions: Ceiba pentandra is already planted as a roadside and shade tree in many tropical countries (Duvall, 2011). We recommend massive cultivation of this species for seedling distribution to farmers and individuals for propagation
Combretum molle R.Br. ex G.Don
Family: Combretaceae
Common names: velvet bush willow, velvet leaf willow
Local names: Wúyàn dámóó (Hausa), ɓoode (Fulfulde)
Combretum molle is a medium-sized evergreen deciduous savanna tree that grows up to 13 m high, with a rounded dense crown, with low hanging branches, and has a characteristic dark grey deeply fissured bark (Hutchison and Dalziel 1927-1954; SANBI, 2010., Parusnath et al. 2023). The leaves are simple, opposite, and densely covered by combretaceous hairs creating a velvety texture especially (SANBI 2010; Parusnath et al.2023). Combretum molle is reported to have many uses in traditional medicine for various ailments including fever, pain, wounds, oedema/dropsy, cough, and colds, as an anthelmintic for hookworm, stomach pains, and a range of infections including HIV/AIDS (Burkhil 2004; Anato and Ketema 2018; Mogashoa et al. 2019; Rademan and Lall 2020;Parusnath et al2023). This species is threatened especially by logging for timber, firewood and charcoal production, overgrazing, deforestation, and land use patterns which often lead to habitat fragmentation, agriculture expansion, drought, and climate change (Clayton 1963;Umar et al. 2020;Mohammed et al. 2022;Umar et al. 2021). This species has recently been assessed as VU B1ab (i, iii, v); D2 by Bello et al. (2019) for Katsina state Nigeria. In this study, we observed a decreasing population size, with only a few numbers of mature individuals in the population. The estimated extent of occurrence is 20 000 km2 and the estimated area of occupancy is 1650 km2. Combretum molle is thus assessed as VU.
VU= B2ab (ii, iii, v)
Recommended Conservation actions: The recommended conservation actions are to further research on the biology of the species and adopt an ex-situ conservation approach.
Name: Crossopteryx febrifuga (Afzel. ex G.Don) Benth.
Family: Rubiaceae
Common name: Sand Crown-berry
Local names:
Crossopteryx febrifuga is a small deciduous endemic savanna tree 1.8–15 m. tall, with rounded crown and pendulous branchlets, but sometimes shrubby; bark pale grey to dark brown, scaly, finely reticulate; young stems glabrous to densely pubescent hairy or tomentose (POWO 2024). Crossopteryx febrifuga is widely distributed in the West African savanna from Tropical Africa - Senegal to Sudan and Ethiopia south to South Africa and Namibia (Tropical Plants Database 2024). Crossopteryx febrifuga is commonly used in African traditional medicine for the treatment of several diseases, such as dysentery, diarrhea, and fevers (Elufioye and Agbedahunsi 2004; Chouna et al. 2015). Preparations of this tree are widely used in Northern Nigeria in the therapeutic management of trypanosomiasis, malaria, and painful inflammatory disorders (Adeola et al.2011).
Although Crossopteryx febrifuga has been reported to have a higher intrinsic resistance to fire (Orwa 2009). Yet this tree is faced with various threats from agriculture (subsistence), deforestation, climate change, and massive cutting of the tree for fuel wood. The wood is used in making utensils, tool handles, and wooden chairs (Burkhil 1985; 2004). The wood has a fine texture. And it is carved for making sculptures (Orwa 2009). The species is rare and is not locally common even in most savanna habitats of the country including some protected areas like Kainiji Lake National Park (Amusa and Jimoh 2010). Another unnoticed or unreported threat confronting this species is the massive cutting down of the tree to make a wooden slate locally called Allo in Hausa language(Verbal comm. and field obs.) usually used in Tsangaya School known as Makarantar Allo or traditional Qur’anic school (Idriss and Hamzah 2021).
Although Crossopteryx febrifuga has most recently been assessed for The IUCN Red List of Threatened Species in 2018. Crossopteryx febrifuga is listed as Least Concern (BGCI and IUCN SSC 2019). Due to the decreasing size of the population, with a small number of mature individuals, the estimated extent of occurrence is 18 500 km2 and the estimated area of occupancy is 200 km2. Crossopteryx febrifuga is thus assessed as VU.
VU= B1ab (ii, iii, v) + 2ab (ii, iii, v)
Recommended Conservation actions:
Further monitoring of the species and sound knowledge of the species' biology and ecological requirements which encompass its regeneration status, are needed for sustainable management of the species.
Daniellia oliveri (Rolfe) Hutch. & Dalziel
Family: Fabaceae
Common name: African Copaiba Balsam Tree,
Local names: Maaje (Hausa), k(ay)arlaa-hi/je(Fulfulde)
Daniellia oliveri is a slow-growing, deciduous tree with a flat-topped, spreading, dense crown; usually growing 9 - 25 metres tall, but with occasional specimens growing tall up to 45m ( Hutchinson and Dalziel 1954). The bark is greyish-white, smooth at first but later flaking off in patches (Schmelzer and Louppe2012). This tree is native to tropical Africa - Senegal to Cote D'Ivoire, east to Sudan and Uganda (Tropical Plants Database 2023). In Nigeria, this multipurpose tree is mostly distributed in the southern Guinea savanna belt of the country (Oyedeji et al.2014) and extends into patches of the derived savanna zones of southwestern Nigeria (Daramola et al. 2021). The plant has numerous ethnobotanical uses well documented in (Burkhil, 1985; 2004). Almost all parts of this tree are useful in the preparation of recipes for various ailments in Nigeria and some Tropical countries where it is grown. One of the salient uses of this species in the northern part of the country is the application of powdered gum exudated from this species to clothes and Hausa native caps to make them shiny (Burkhil 2004). The young leaves are used for cattle fodder, and the leaves, bark, roots, and gum are used in traditional medicine, both internally and externally, for a range of conditions (Schmelzer and Louppe2012). This tree faces significant threats from intensified agriculture activities (mostly slash and burnt), deforestation, and plant collecting. This tree is harvested in large quantities for making commercial pestles and mortar and logging, where the wood is used for making canoes/boats and furniture as previously reported elsewhere (Schmelzer and Louppe 2012). We observed massive logging of this species especially in Benue, Niger, and Taraba states, where the wood from the tree is used as timber in furniture and household items such as chairs, benches, stools, mortars and pestles. However, the activities listed above worsened by climate change have fragmented the habitat of this species thereby reducing the population of the species as the case with other countries in Sub-Saharan Africa (Kaly et al. 2021; Compaoré et al. 2022). Populations of this species range from a maximum of 10–20 individuals at a single site, and these are mostly juvenile trees. The extent of occurrence (EOO) of D. oliveri was estimated to be 4300 km2, whereas its area of occupancy (AOO) is estimated to be 1500 km2. The decline in the EOO, loss of habitat, and number of individuals in populations, thus qualifies the species as Endangered at the regional level of Nigeria.
Importantly, this species has not been previously assessed locally but assessed globally as Least Concern (LC) IUCN (2022).
EN= Endangered B1ab (i, ii, iii, iv)
Recommended conservation actions: This species can be conserve for both ex situ and in situ through propagation and reintroduction to the wild.
Detarium microcarpum Guill. & Perr
Family: Fabaceae
Common name: Sweet Dattock
Local names: Taura (Hausa), konkee-hi/je (Fulfulde)
Detarium microcarpum is a multipurpose agroforestry shrub sometimes referred to as a small tree with an irregular crown, 5-10 m tall, and is recognized by its leaves, 15 cm long, paripinnate or imparipinnate with translucent ones (Hutchison and Dalziel, 1954). They contain four to twelve alternate or sub-opposite leaflets 11 cm long and 3 to 5 cm wide (Tchatcha et al., 2022). The bark is reddish brown, cracked on woody twigs, clear, smooth, and greenish yellow on young shoots; its flowers are grouped in axillary panicles 15 to 25 cm long and 6 to 10 cm wide (Tchatcha et al., 2022). In Nigeria, this species is found in the Sudano-Guinean savanna area of the country. D. microcarpum is one of the prominent elements of the local population's socioeconomic life (Lamy et al., 2021), and the species is highly appreciated by the local communities for its food, medicinal and wood-fuel uses (Gaisberger et al., 2017, Agbo et al., 2019., Lamy, 2021., Houénon et al., 2022). The stems of D. microcarpum have been reported in Benin, to be fully used in the production of wood charcoal, while in Burkina Faso, D. microcarpum is regarded as one of the top ten food woody species in the country (Houénon et al., 2022). In Nigeria, the plant is used for many traditional medicine applications. The roots, stems, bark, leaves, and fruits are all used to treat ailments such as tuberculosis, meningitis, itching, syphilis, and diarrhea (Burkhil, 1985, 2004). Detarium microcarpum is threatened by overharvesting for wood, mainly for fuel, expansion, and intensification of agriculture, and uncontrolled fires that prevent regeneration (Kouyate and Lamien 2011). Nevertheless, overharvesting of plant parts causes low densities and occurrence, especially in tree species that are slow-growing, and many have specific habitat requirements that limit their distribution (Van Wyk and Prinsloo, 2018, Agbo et al., 2020). This threat is intensified by climate changes as any increase in temperature and/or decrease in rainfall may modify the extent and shape of species’ suitable habitats; thus, inducing a reduction of global species’ diversity (Agbo et al., 2020). The geographical range of this species is narrow and its survival is restricted mostly to the protected areas in the north. This species has been regarded as threatened species mainly due to the massive harvesting of leaves, roots, and stems for herbal medicine preparations (Bello et al., 2019) and especially logging for wood and intensification of agriculture with the most worrisome threat of uncontrolled wildfires preventing seed regeneration (Tchatcha et al., 2022). Although globally this species has been assessed as assessed as Least Concern (LC), Hills (2019). However, Bello et al., (2019) assessed this species as Critically Endangered (CR) in their provincial report.
Overall the population size of this species is decreasing with a small number of mature individuals of < 50; the estimated extent of occurrence and area of occupancy (EOO) is < 100 km2 and the area of occupancy (AOO) is 2000 km2. Therefore, Detarium microcarpum is assessed as critically endangered (CR)
CR= B1ab (ii, iii, v)+2ab(ii, iii, v); D
Recommended conservation actions: Due to the adverse effects of climate change which is affecting the natural regeneration of many species in the wild, assisted regeneration is suggested for populations in areas where suitable habitats under favorable environmental conditions (Gaisberger et al., 2017).
Diospyros mespiliformis Hochst. ex A.DC.
Family: Ebenaceae
Common name: African ebony (Eng.);
Local names: Kányà (Hausa), nelɓi (Fulfulde)
Diospyros mespiliformis is an evergreen forest and savanna tree up to 25 m high in the savanna, and up to 45 m in forests and usually has a dense rounded, and buttressed stem (Hutchison and Dalziel 1927-1954, Burkhil, 2004). The bark is grey-black or black, smooth in young trees rough with small regular scales in older trees, and pinkish when slashed (Orwa et al., 2009., Hyde et al., 2023). Leaves are simple, alternate, leathery, and dark green. The margin is smooth and new leaves in spring are red, especially in young plants. Flowers are cream-coloured and bell-shaped. Male flowers are arranged in stalked bunches and female flowers are solitary and the fruit is a fleshy berry, with an enlarged calyx, yellow to orange when ripe (SANBI, 2010). D. mespiliformis is widely distributed throughout West Africa and other tropical African countries (Burkhil, 1985). In NSZ of Nigeria, the tree is exclusively distributed in the Sudano-Guinean area and has been recorded in the forest zone of the country (Dunn and Agom 1992., Ijomah et al., 2022). The tree parts have various ethnobotanical applications in traditional medicine preparations, such as food and utilization in the production of various farming tool handles, and are sawn as timber (Burkhil, 2004). Diospyros mespiliformis is threatened by, especially overgrazing, habitat fragmentation, incessant deforestation, random cutting of trees for making farm implements handle, agricultural intensification especially slash and burn farming, aridity, drought, and climate change (Bello et al., 2019). The species is very rare in many localities visited including even the protected areas. It has been reported to be endangered in many places they are found mainly due to overexploitation (Ali et al.2020). The geographic distribution is restricted and mostly skewed towards the Guinean-Sudano zone of the country that is inundated. The current population size is decreasing with a small number of mature individuals throughout the area visited. The estimated extent of occurrence is 4800 km2 and the estimated area of occupancy is 100 km2. Based on the above criterion, Diospyros mespiliformis is thus assessed as EN.
EN= B1ab (ii, iii, v) + C2ab (i); D
Recommended Conservation Actions:
Despite D. mespiliformis recently being assessed as CR by Bello et al., (2019) for Katsina state, Nigeria, and globally as LC (BGCI and IUCN SSC, 2021). This species is not protected neither by international or local law, regardless of its role in the ecosystem and the food web in which it is involved (SANBI, 2010). Therefore, the appropriate conservation approach is to conduct more research on the propagation and planting of this species.
Entada africana Guill. & Perr.
Family: Fabaceae
Common name: African ebony
Local names: Tààwátsáá (Hausa), paɗe waanduuhi(Fulfulde)
Entada africana is a small tree that is mostly found in tropical and subtropical regions (Yusuf and Abdullahi, 2009). And in Nigeria, this tree grows in the Guinea-Sudanian zone of the country (Hutchison and Dalziel, 1954., Burkhil 1985) and occasionally has been recorded in the montane vegetation (Chapman and Chapman, 2001). This tree has multiple uses in traditional medicine for various types of illnesses, the leaves, stem bark, and root of the tree are used against fever, as food, source of gums, in some small carpentry works, and as insecticides (Yusuf and Abdullahi, 2009). Even though E. africana is threatened by overharvesting for large-scale medicinal uses, intensified grazing, agriculture, logging of wood as light timber and climate change. In this study we found Entada africana to be abundant and common where it occurs such as Gashaka Gumti National Park, Yankari Game reserve and several other places outside the protected areas. We estimated the extent of occurrence to be > 20 000 km2 and the estimated area of occupancy is 2000 km2. Entada africana is thus assessed as LC. This is in contrast to Bello et al., (2019), who provincially assessed this species as Critically Endangered.
LC= Least Concern
Recommended Conservation actions: Based on the population status of this species, we recommend continued monitoring of the population trend in the wild for posterity.
Erythrina senegalensis Schumach. & Thonn.
Family: Fabaceae
Common names: Coral tree; coral flower
Local names: Jinjiriya (Hausa), beeɗoo-hi/je (Fulfulde)
Erythrina senegalensis is a spiny shrub or tree with an open crown; it usually grows around 3 - 4.5 m tall, but sometimes reaches up to 12 - 15 m (Hutchison and Dalziel 1954). Erythrina senegalensis has a wide distribution range across West Africa up to northern Cameroon (Burkhil2004). Erythrina senegalensis has multiple uses in traditional medicine to cure numerous diseases. The stem bark is used to treat Jaundice or yellow fever, popularly called in the Hausa language “Shawara. E. senegalensis is also used extensively to treat bronchial infections, coughs, venereal diseases, and throat inflammation. The powdered bark and leaves are used in the form of soup to treat female infertility (Doughari;2010;Souleymane et al.2021). Extract of the bark is given to women during childbirth (Harley et al. 2022). Erythrina senegalensis suffers multiple sources of disturbance from debarking anywhere they are found, and this continuous debarking results in the death of medicinal trees (Bodeker et al. 2014; Nndwammbi et al.2018; Cukor et al. 2019; Mohammed et al. 2022). This has made the species rare and the population size is decreasing, the estimated extent of occurrence is 15,000 km2 and the estimated area of occupancy is 1500 km2. Erythrina senegalensis has recently been assessed at the regional level as Lower Risk (LR) for Sudan Savanna in Katsina State, northwestern Nigeria (Bello et al. 2019) and globally the species has not been assessed as Least Concern (LC) Contu (2012). Based on the above, Erythrina senegalensis is thus assessed as VU.
Vulnerable= VU= B2ab (ii,iii,v)
Recommended Conservation actions: Erythrina senegalensis is not protected by any international or national law and there are no known conservation measures specifically for this species. Therefore, seed collection of E. senegalensis for deposition in secure repositories and propagation of this species should be encouraged as an ex-situ conservation measure.
Erythrophleum suaveolens (Guill. & Perr.) Brenan
Family: Fabaceae
Local names: Ordeal Tree, African Rosewood
Common names: Gwoska (Hausa), gwoskaa (Fulfulde)
Erythrophleum suaveolens, is a medium-sized to large deciduous tree that can reach heights of 30 m (Hutchison and Dalziel, 1954). This tree is widely distributed tropical Africa and was introduced to South Tropical Asia as an ornamental plant (Ziba et al. 2017). Moist environment, semi deciduous forest, gallery forest has been reported to the favourable habitats for this species (Keay 1989). Various preparations of the plant parts have been used to treat cardiac problems, venom intoxication, and inflammatory diseases Fadeyi et al., (2013) and several other medicinal preparations, see Burkhil (1985). One of the notable uses of this species is the preparation of the bark and leaves as arrow and fish poison (Ekhuemelo et al., 2019). The wood of E. suaveolens is appropriate for furniture, flooring, dock work, railway sleepers, turnery, construction, harbor and bridges, boat building, and wheel hubs (Ekhuemelo et al., 2019). This tree is threatened by numerous threats, especially from, agricultural escalation especially slash-and-burnt farming, habitat fragmentation, deforestation, and illegal felling of trees for charcoal production (Olorunishola and Akintunde 2003; Ziba et al. 2017). E. suaveolens is now becoming one of the most important timber species harvested from where they are found in NSZ such as Taraba and Adamawa states respectively. The species is rare and local, uncommon in most places in the NSZ of the country, and fairly common in the Southern part of Nigeria (Keay 1989). The population size is decreasing with a small number of mature individuals as a result of seed dormancy that contributes to the low population (Ziba et al. 2017). This species has been assessed as least concerned (LC) by (Hill 2019). The estimated extent of occurrence is > 20 000 km2 and the estimated area of occupancy is < 650 km2. Erythrophleum suaveolensis thus assessed as vulnerable (VU).
VU= B2ab (ii,iii,v)
Recommended Conservation actions: Further monitoring of the species and sound knowledge of the species' biology and ecological requirements which encompass its regeneration status, are needed for sustainable management of the species.
Faurea rochetiana (A.Rich.) Chiov. ex Pic.Serm.
Family: Proteaceae
Common name: broad-leaved boekenhout
Local name: Bobboji (Fulfulde)
Faurea rochetiana is a deciduous shrub or small tree with a crooked habit and spreading crown, which can grow up to 10 metres tall with flower spikes markedly catkin-like 10–15 cm long (Hutchison and Dalziel 1954). The wood is yellowish-brown to red or red-brown, often figured, hard, and durable (Burkhil 1985). This plant grows exclusively in the drier savanna zone and it is rarely distributed (Hutchison and Dalziel 1954). The plant is used in traditional medicine for the treatment of diarrhoea, indigestion, colic, cough, venereal diseases, schistosomiasis, rheumatism, dysmenorrhea, headache, and skin complaints, and as a tonic (Lemmens 2011). The bark is harvested in large quantities and is used for tanning leather and provides a red dye (Burkhil, 2004 and Lemmens 2011). Faurea rochetiana is known from only a few locations and mostly all of which are confined to the rocky-mountains of Jos Plateau state (1300 m). Our field assessment at this location, estimated the number of mature individuals of the species to be<50. This area is estimated to be <4 km2, and this area is not a protected area. The population is threatened by logging, grazing, and agricultural activities, where the land is cleared for planting food crops. However, these ongoing threats to the only known population, the decline in habitat quality, and the number of mature individuals, therefore, support the assessment of F. rochetiana as Critically Endangered.
CR= B1ab (iii) +2ab (iii) +B2a (iii); D
Recommended Conservation actions: Greater public awareness on the need to conserve wild species and propagation of this species for both in situ and ex situ conservation
Hymenocardia acida Tul.
Family: Phyllanthaceae
Common name: Heart-fruit
Local names: ján ítaacéé or ján yááro (Hausa), boɗeehi, pattoyi (Fulfulde)
Hymenocardia acida is an indicator species in the Guinea savanna vegetation and grows up to s 9 m high, with, gnarled and twisted with characteristic rough rusty-red bark (Hutchison and Dalziel 1954). The tree is mostly found in the wooded savanna region of Senegal to Western Cameroon and is widespread throughout tropical Africa (Orwa et al. 2009; Burkhil 1985). Hymenocardia acida is mainly used for the preparation of aphrodisiac and anti-dysenteric (Burkhil 1985; 2004; Sabo et al. 2018). This species is restricted to the savanna zone of Nigeria which is inundated by cattle grazing and agricultural activities. H. acida is under numerous threats, especially the harvesting of the roots for medicinal uses, drought, climate change, overgrazing, and cutting of the trees as fuel wood (Burkhil 2004; Sabo et al. 2017). The harvesting of the root is not a sustainable way of harvesting of medicinal plants (Chen et al. 2016; Zschocke et al.2020).The species is rare and has a restricted distributional range within the country. The population size is decreasing with a small number of mature individuals, the estimated extent of occurrence is 18 000 km2 and the estimated area of occupancy is 200 km2. Hymenocardia acida is thus assessed as endangered (EN).
EN= B2ab (ii,iii,v)
Recommended Conservation actions: Further monitoring is needed to better understand the population trends of the species in Nigeria and research activities on its reproductive biology and ecology are recommended
Isoberlinia doka Craib & Stapf
Family: Fabaceae
Common name: Forage plant
Local names: Báƙár dóókáá (Hausa), kubaa-hi/je (Fulfulde)
Isoberlinia doka is an evergreen tree with a flat, spreading crown; it can grow from 10 - 20 meters tall, often hollow, in the Soudano-Guinean forest from Mali to Nigeria and across central Africa to Sudan and Zaïre (Burkhil 1985; Tropical Plants Database 2023). Over a decade ago (Louppe, 2012), estimated the cover of Isoberlinia doka woodlands in West Africa to be close to 20 million ha. We observed the distribution trend in Nigeria to be skewed towards the Guinea-savanna zone of the country. This plant is exploited for timber outside the protected area, which jeopardizes its population. Agricultural activities particularly the subsistence type, together with excessive grazing and urbanization are leading to fragmentation of the population. This has driven many species into local extinction in most habitats visited outside the park. Isoberlina doka has just recently been assessed locally as Vulnerable (VU) by Bello et al. (2019), for the Sudano region of Katsina state, and globally on the IUCN assessment as Least Concern (LC) (Contu, 2012). The population size of this species in Nigeria is decreasing, the estimated extent of occurrence is > 20 000 km2 and the estimated area of occupancy is 1500 km2. Isoberlina doka is thus assessed as VU.
VU= Vulnerable, B2ab (ii,iii,v)
Recommended conservation actions: However, the possible conservation actions are to further research the biology of the species and adopt an ex-situ conservation approach.
Khaya senegalensis A. Juss.
Family: Meliaceae
Common name: African mahogany
Local names: Madachi (Hausa), ɗaalee-hi/je (Fulfulde)
Khaya senegalensis is a deciduous evergreen tree, 15-30 m high, with a wide dense crown and thick stem, mostly found growing in savanna and especially by streams in the savanna regions (Hutchison and Dalziel 1954; Keay 1989; Burkhil 2004; Nikiema and Pasternak 2008). K. senegalensis one of the most highly valued plants in terms of traditional medicines preparations. The bark is bitter and the decoctions are widely taken against gastrointestinal disorders and several other ailments in African traditional medicine (Olowokudejo and Nyananyo 1990; Burkhil 2004; Nikiema and Pasternak 2008). K. senegalensis is economically important as a source of highly prized timbers such as the commercial mahoganies whose vessels contain oleo-resin that make them durable and resistant to insect and fungus attack ((Olowokudejo and Nyananyo 1990). K. senegalensis was previously assessed at the regional level as Vulnerable (VU) for Katsina state (Bello et al. 2019). The species has been evaluated at a global level since 1998 as Vulnerable (VU), though needing updating (IUCN 2012). However, it is no exaggeration to say that K. senegalensis is one of the most preferred timbers for roofing in northern Nigeria. This is due to its ability to resist fungi attacks, and thus has put a huge demand on the species subsequently leading to a drastic decrease in the population and number of mature individuals which support the classification of the species as Critically Endangered.
CR= B2ab (ii,v)
Conservation actions: Khaya senegalensis is not protected at national or international levels. We recommend the inclusion of this in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to restrict international trade in its woods. And propagation of seedlings and donate them to the local communities to be planted either as avenue trees or inculcated into agroforestry.
Kigelia africana (Lam.) Benth.
Family: Bignoniaceae
Common name: Sausage tree
Local names: Nòònòn gííwáá (Hausa), gillaa-hi/je (Fulfulde)
Kigelia africana is a medium-sized tree up to 25 m - 35 m tall and produces flowers variable in colour, purplish-red, purple-yellow, orange, greenish-yellow, and sometimes spotted with darker reddish colours; fruits like long sausages (Hutchison and Dalziel 1954). Kigelia africana is a native of the African continent where it is commonly found in the southern, central, and western regions, and has been introduced to some countries in South-East Asia (Bello et al. 2016). This tree species is among the widely used throughout Africa for a variety of purposes, particularly in traditional medicine for the preparation of various recipes (Burkhil 1985). The notably documented ailments treated by K. africana include skin complications and also to treat dysentery, constipation, wounds, ulcers, gonorrhea, rheumatism, and abscesses among many others (Burkhil 2004 Bello et al. 2016). Though K. africana is reported to be widely distributed in Africa (Hutchison and Dalziel 1954) and has since been used as an agroforestry tree elsewhere (Bello et al. 2016). In Nigeria, K africana is distributed in the southern and north-central regions of the country (Hutchison and Dalziel 1954). The species is fairly common and distributed in the southern part of Nigeria, but is rarely in the savanna zone of northern Nigeria, particularly the Sudan and the Sahel zones of the country. The population has been assessed globally as Least Concern (LC) by the IUCN (Rivers and Mark 2017). However, this species' population in the savanna zone is decreasing, and the number of mature individuals and the population density has been significantly reduced and the species has disappeared from its previously reported habitats. The estimated extent of occurrence is > 22 000 km2 and the estimated area of occupancy is 460 km2. Based on this, Kigelia africana is thus assessed as EN.
EN= Endangered B2ab (ii, iii, v)
Recommended conservation actions: We recommend an intensified effort on the in situ conservation of this species and further research on the distribution trend and reproduction biology of this species
Lannea acida A. Rich
Family: Anacardiaceae
Local names: Fààrúú (H), faruhi (Fulfulde)
Lannea acida is a tree to 10 m high, and bole 2–3 m in girth, of savanna, particularly in rocky areas and is native to W. Tropical Africa to Cameroon and has a thick fissured bark that helps the tree resist the annual savanna bush-fires (Burkhil 1985). This tree or shrub grows primarily in the seasonally dry tropical biome, often on gravelly (deep) soils, rocky places, and hills; bare granite rock; granitic hardpan (Tropical Plants Database 2023). The tree has been used in numerous traditional medicine preparations in Africa. Notable medicinal uses of L. acida include injuries, inflammation and pain, gastrointestinal problems, fever and malaria, gynecological and pregnancy disorders, hemorrhoids, skin diseases, and infections (Burkhil 1985; 2004). The tree occurs in one of the driest regions of the Sudanano and the Sahelian Savanna region of the country. Lannea acida is threatened by seasonal debarking for fiber used by nomadic pastoralists. This Seasonal debarking could consequently lead to the progressive drying and decaying of the tree (Nndwammbi et al. 2018). This is due to damage to the phloem thereby, exposing it to desiccation and fungal or parasite attack (Gaoue and Ticktin 2008). The wood of L. acida is whitish and soft and it is used in making small stools, planks, and other utensils (Tropical Plants Database 2023). There is no doubt that this plant is being exploited commercially (Bello et al. 2019), as also reported in Senegal (Burkhil 2004). This commercial exploitation is posing a new potential threat, which has not yet received any conservation (Bello et al., 2019). Lannea acida is rarely available, especially outside the protected areas but is sometimes available within some protected areas like Kainji Lake National Park (KLNP) and Kamuku National Park (KNP), with a restricted geographical range. The population size is decreasing with a small number of mature individuals, the estimated extent of occurrence is 18 500 km2 and the estimated area of occupancy is 2000 km2. Lannea acida has previously been assessed from the Sudanian region of Nigeria as VU by Bello et al. (2019) and globally by (BGCI and IUCN SSC, 2019). However, in this study, L. acida is thus assessed as VU.
VU= Vulnerable Endangered B1ab (ii, iii, v) + 2ab (ii, iii, v)
Recommended Conservation actions: Further monitoring and establishment of ex-situ conservation programmes (see Bello et al. 2019)
Lophira lanceolata Tiegh. ex Keay.
Family: Ochnaceae
Common name: Dwarf Red Ironwood
Local names: Míjìn káɗányà (Hausa) kareehi gori (Fulfulde)
Lophira lanceolata is a tree that grow up to 24 m with a trunk diameter of 70 cm, and are widespread in the Sudano-Guinean savanna of Central and West Africa (Hutchison and Dalziel, 1954 and Dicko et al., 2022). This plant is one of the multipurpose trees found in their areas of distribution. The wood of L. lanceolata is used for charcoal and as firewood, while the leaves, bark, and roots are used in the treatment of various pathologies such as gastrointestinal disorders, hemorrhoids, wounds erectile dysfunction and several others (Burkhil, 1985 and 2004). Lophira lanceolata is a light-demanding pioneer tree whose seeds are processed in an edible oil widely used in food, cosmetics, and medicinal preparations in West Africa (Ewedje et al. 2020). The tree is highly valued, for its wood, medicinal products, oil, and fodder (Hounsou-Dindin et al. 2022). Several workers have reported the species of L. lanceolata as excellent firewood because it produces hot flames and little smoke and is also a good source of charcoal (Mapongmetsem 2007; Fontodji et al. 2007; Msoffe 2017; Dicko et al. 2022; Ihinmikaiye et al. 2022). This species undergoes multiple disturbances across its distribution range, which negatively affects its survival. These include agricultural intensification, cutting of trees to make pestle and mortar, charcoal production, and climate change. The worrisome threat is the adverse ecological conditions that have negatively impacted the development and growth of the regeneration of this species in its natural habitats (Dicko et al. 2022). According to (Fawa et al. 2014), even if the species has high seed production in certain areas where they are found, regeneration appears very slow in response to anthropogenic pressures and seed collection for edible oil production. Also, the fruits and seeds of L. lanceolata are prone to attack by pests and this could affect its regeneration (Dicko et al. 2022). This species has just recently been evaluated as Least Concern (LC) at the global level (IUCN 2019). And has not been evaluated locally for Nigeria, and there are no management programs or conservation strategies put in place for the sustainability of the species. The total number of this species and its distribution has declined and are rare in most habitats, especially in the Sudan and Sahel zone. The population size of this species is fragmented, and there is a sharp decrease in the population size, with a majorly small number of mature individuals. The estimated extent of occurrence is 18 000 km2 and the estimated area of occupancy is 200 km2. Lophira lanceolata is thus assessed as EN.
EN= Endangered B2ab (ii, iii, v)
Recommended Conservation actions: Therefore, it is recommended that other methods of species conservation, such as natural regeneration and planting of indigenous plants, should be given priority through incentives and provision of nursery materials to rural people (Bello et al. 2019).
Parkia biglobosa (Jacq.) R.Br. ex G. Don
Family: Fabaceae
Common name: Locust beans
Local names: Dóòráwà (hausa), naree-hi/je (Fulfulde)
Parkia biglobosa is a multipurpose tree found in many African countries and can grow up to a height of about 20–30 m (Hutchison and Dalziel, 1954; Heuzé et al. 2019). Parkia tree has a dense, widely spreading umbrella-shaped crown and a cylindrical trunk that can reach 130 cm in diameter. Tree bark is longitudinally fissured, scaly between the fissures, and thick, ash-grey to greyish-brown in colour (Heuzé et al. 2019). There is no doubt, this tree is one of the most important indigenous tree species that is highly valued by the local populations in the Sudano-guinea savanna region of Nigeria. The species provide several goods and services (food, medicine, and income) to rural populations, contributing to socioeconomic values (Okoye et al. 2014, Lokonon et al. 2022). The seeds and pulp of P. biglobosa are widely consumed by rural and urban populations, and their sale generates substantial income for many people, particularly women (Lokonon et al. 2022). Again, the seeds are harvested in large quantities for the production of a kind of local pudding called daddawa (in Hausa), used for seasoning soup. This condiment used for sauce and soup seasoning is one of the most important commercial products traded nationally and internationally (Akpi et al. 2020; Mogmeng et al. 2020)
Despite these elaborate uses of this species, the populations of this species are highly threatened due to over-exploitation of the fruits and seeds. The harvesting of leaves and fruits may also have a negative impact on the regeneration process because the maintenance of regeneration capacity also depends on the maintenance of key regeneration principles such as pollination, development and dispersal of seeds, germination, and plant growth (Koura et al. 2011).
Logging for timber used in making pestles, mortars, bows, hoe handles, and seats (Amusa et al. 2014) is another threat confronting this species. This logging scenario was particularly observed in Taraba and Adamawa states and received total condemnation from the stakeholders and community leaders. This could be as a result ofthe socioeconomic benefits the tree offers to the community members.
Conversely, other threats include habitat fragmentation, overgrazing (as headers loop branches to feed their cattle) deforestation, agriculture, drought, and climate change (Padakale et al. 2015).
This species is known from several localities from the Savanna zone of Nigeria. The population size is decreasing, the estimated extent of occurrence is > 20 000 km2 and the estimated area of occupancy is whereas the area of occupancy (AOO) is estimated to be 2400 km2. Parkia biglobosa is thus assessed as VU. This is in congruence with Bello et al. (2019), who provincially assessed the species as VU for the Sudan savanna of Katsina state, Nigeria. While the global assessment as Least Concern (LC) by BGCI and IUCN/SSC (2019).
VU= Vulnerable B2ab (ii, iii, v)
Recommended Conservation actions: Parkia biglobosa is not domesticated nor inculcated into the mainstay agroforestry farming system of Nigeria. We suggest the adoption of both ex situ and in situ in conserving this species by propagation of this species in the agroforestry trees in the country.
Prosopis africana (Guill. & Perr.) Taub.
Family: Fabaceae
Common name: false locust
Local names: Ƙíryà (Hausa), kahi (Fulfulde)
Prosopis africana is a savanna tree, which reaches 4-20 m in height; has an open crown and the bark is very dark, scaly, slash orange to red-brown with white streaks (Orwa et al. 2009). The tree has pale drooping foliage and very hard wood; flower spikes are yellowish and fragrant; pods stout, roughly cylindrical, with loose rattling seeds (Hutchison and Dalziel 1954). Prosopis africana is a tree with multiple uses that grows in savanna regions of western Africa (Keay et al. 1964). This tree is regarded as a multipurpose tree because all the parts of the trees are used either in traditional medicine preparations, as fodder, condiments or as spiritual paraphernalia. The leaves are used in the treatment of headaches and toothache as well as various other head ailments. The bark is used in the treatment of skin diseases, caries, fevers, and eyewash (Tropical Plants Database 2023). The roots are diuretic and are used to treat gonorrhea, tooth and stomachache, dysentery, and bronchitis (Burkhil 2004). The fermented seeds of this plant are used in producing a condiment which is used as a food seasoning agent known as “daddawa” in Hausa (Ezike et al. 2010).
P. africana is highly valuable and is increasingly threatened by excessive demand for tree products (Agboola 2004), ranging from the wood used as timber for pestles, mortars, and axe handles to charcoal production. It has been reported that P. africana is one of the most preferred trees for the production of charcoal (Ekhuemelo et al. 2004; Salamatu et al. 2021). This charcoal from P. africana is highly valued by blacksmiths commonly called “Makera” in Hausa (Agboola 20024), because of its longer burning duration and less ash (Salamatu et al. 2021). Other uses of this plant include local bridge construction, firewood, and making of handles for farm implements amongst others because its wood is known to be hard, durable, resistant to termites, and easy to carve. Another unnoticeable threat to this plant and many other species is the cutting down of the saplings mainly by yam farmers for staking. This has already been reported in some parts of Nigeria (Tsado 2012) and elsewhere (Beckford 2009 Wumbei et al. 2022). Unfortunately, this threat has not yet received any conservation attention despite being a potential threat to the tree species in the north-central states (Guinea savanna) such as Niger, Benue, Nassarawa, and Kwara states where yam is well produced. And to the northeastern states such as Adamawa and Taraba where yam is also produced in large commercial quantity. Our field visits to these areas recorded a large habitat fragmentation and the total conversion of a Guinea savanna to a Sudan vegetation type. Trees are sparsely recorded here as the sapling that was supposed to grow and replace the trees have been destroyed in these areas. P. africana was hardly found outside the protected area. Even inside the protected area, the total number of mature individuals in the population is less than 10 species. The tree was mostly found growing in rocky habitats where its regeneration could be difficult. Because of its multiple uses and products, populations of P. africana are being over-exploited and are rapidly decreasing in across West Africa (Tchoundjeu et al. 1997) including Nigeria (Abubakar et al. 2018). The estimated extent of occurrence is 550 km2 and the estimated area of occupancy is 450 km2. This justifies the assessment of Prosopis africana as Endangered (EN). This corroborates the provincial assessment of Bello et al. (2019). Conversely, P. africana has been assessed globally by the IUCN (2019) as Least Concern (LC).
EN= Endangered B1ab (ii, iii, v) +2ab (ii, iii, v)
Recommended Conservation actions: Prosopis africana is not protected either nationally or regionally. Domestication of the species in the mainstay agroforestry system of Nigeria is recommended. And alsoestablishing national laws on harvesting certain species for charcoal production should be enacted. License issuance for charcoal production by the government should be implemented (Salamatu et al. 2021) at the national level.
Name: Pseudocedrela kotschyi (Schweinf.) Harms
Family: Meliaceae
Common name: Dry zone cedar
Local names: Tùùnâs (Hausa), boodi(Fulfulde)
Pseudocedrela kotschyi is a deciduous tree with an oblong to pyramid-shaped, usually dense crown; it can grow up to 12 m tall with occasional specimens to 20 m (Tropical Plants Database 2023), and widely spread in the savanna zone from east Senegal to western Ethiopia, Uganda and Nigeria (Burkhil 1985; 2004). Pseudocedrela kotschyi is an important medicinal plant that has been extensively used in African traditional medicine system for the treatment of a variety of diseases, particularly as an analgesic, antimicrobial, antimalarial, anthelminthic, diuretic, aphrodisiac, and antidiarrheal agent (Alhassan et al. 2021). This tree sometimes is referred to as hard cedar-mahogany and is used as timber, shade, firewood, chewing stick, and arrow/fish poison, and has several uses in veterinary and traditional medicine (Antwi et al. 2021). At the same time, this tree is one of the most widely exploited trees in NSZ of the country for timber and medicinal uses (Alhassan et al., 2021), but unfortunately, this tree is faced with regeneration problems due to seasonal savanna fire, loss of seeds to rodents feeding on it and easy attack on the seeds by insects (Déguénonvo et al. 2023). Pseudocedrela kotschyi has most recently been assessed for The IUCN Red List of Threatened Species in 2018. Pseudocedrela kotschyi is listed as Least Concern (BGCI and IUCN SSC 2019).
The extent of occurrence (EOO) of P. kotschyi in the NSZ of Nigeria is estimated to be 60095 km2 (exceeding the upper limit for Vulnerable status under the criterion B1), whereas its minimal area of occupancy (AOO) is estimated to be 44 km2, within the limit for Endangered status under the criterion B2. The species occurs in three protected areas Gashaka Gumti National Park, Kainji Lake National Park, and Kamuku National Park. The other sites where this species was recorded are unprotected and subject to deforestation, subsistence farming, indiscriminate logging, overharvesting of the tree for charcoal making and the bark for medicinal purposes, and clearing for agriculture. We expect that the ongoing loss of its habitat will induce a decline in the number of mature individuals, and thus AOO. Based on the above criteria Pseudocedrela kotschyi is therefore assessed as VU
VU= B2ab (ii, iii, v)
Recommended Conservation actions:
Further monitoring of the species and understanding of the species biology and ecological requirements, which encompass its regeneration status, are needed for sustainable management of the species (Assédé et al. 2012; Déguénonvo et al. 2023).
Pterocarpus erinaceus Poir
Family: Fabaceae
Common name: African rosewood
Local names: Mádóóbììyáá (Hausa), i'amhi (Fulfulde)
Pterocarpus erinaceus is a deciduous multipurpose native tree to the Guineo-Sudanian and Sudano-Sahelian zones. This plant usually grows up to 12- 15 m tall, with some specimens reaching 25 m tall, and has a rounded, open crown (Heuzé et al. 2019b). Pterocarpus erinaceus is native to West and Central Africa and grows in woodland savanna, dry forest, and open land. The tree can also be found on the margins of dense forests or in humid coastal savanna (Heuzé et al. 2019b). In terms of distribution, the P. erinaceus tree grows throughout West and Central Africa, ranging from Senegal in the west to the Central African Republic in the east (Orwa et al. 2009). Pterocarpus erinaceus has numerous uses ranging from fodder for animals, edible cooked leaves, and timber and has diverse uses in traditional medicine to treat infections, diarrhea, fever, and syphilis and used as an aphrodisiac and insect repellent (Burkhil 2004; Duvall 2008). Other uses of P. erinaceus include yielding a resin that dyes fabrics the wood is a source of charcoal and the bark decoction is taken as blood tonic (Amusa et al. 2010; Umar et al. 2020). In Nigeria, P. erinaceus is distributed mostly in the guinea savanna zone of the country, with patches of the population recorded in the southwestern part of the country (Hutchinson and Dalziel 1954). This tree has a wide area of distribution across the country, extending several kilometers square (km2). Unfortunately, this distribution range is currently decreasing as may be the case in other West African countries (Dimobe et al. 2022). The main reasons for the decline in its population are overexploitation and land conversion (Heuzé et al. 2019). Due to the high commercial value of its wood, the species had been subjected to an international timber trade from West Africa to Asia, notably China (Biaou et al.2023). This has put the species under constant pressure and is heavily exploited for timber, animal feeding, and land conversion (Adjonou et al. 2020; Biaou et al.2023). Often, herders loop down the branches of this species to feed their animals. Also, the high demand for African rosewoods on the international timber market (Nodza et al. 2022b) has led to massive logging of this species from every environment across every natural habitat and illegally from protected areas in Nigeria (Nodza et al. 2022b).
Thus, the combination of these threats has led to the disappearance of Pterocarpus erinaceus in some habitats in Nigeria. During our field survey, we observed less than 10 small or immature individuals in the few populations we encountered this species. Apart from the above-mentioned threats, climate change could be another major threat that is capable of impeding the natural regeneration and distribution of P. erinaceus (Zhang et al.2017; Adjonou et al. 2020; Enríquez-de-Salamanca 2022; Erdozain et al. 2023). Based on this, Pterocarpus erinaceus is thus, assessed as Critically Endangered (CR). This corroborates the previous international assessment of P. erinaceus in Burkina Faso as CR (Dimobe et al. 2022), and globally as EN (Barstow 2018; CITES 2018).
Although there have been several international conservation actions to protect this species including felling/export bans, listing and up-listing on it on many appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) (Dumenu 2019). And other ex-situ conservation approaches through establishing different plantations across Nigeria. However, CITES controls trade and does not impact local loss-causing factors, such as incessant logging and indiscriminate deforestation. Also, the current climate change is likely to slow the natural regeneration of the plant, which could lead to changes in the distribution of species, as well as reductions in population size and local population extinctions (Adjonou et al. 2020).
CR= Critically Endangered, B1ab (ii, ii, iv)+2ab(ii, iii, v); C2a(v);D
Recommended Conservation actions: Due to the overexploitation of P. erinaceus in its distribution range, the Nigeria government and several NGOs such as Nigeria Conservation Foundation (NCF) have initiated programs across the country, especially in the distribution areas of this species to train people on how to domesticate and raise seedlings of this species for regeneration in the wild. Unfortunately, this was met by stringent challenges of raising seedlings from seeds of P. erinaceus due to its hard impermeable seed coats restricting the entry of both water and oxygen that will aid its germination (Peter et al.2021). And lack of resources has widely been reported as one of the constraints of seedlings raising (Danjuma et al.2014; Oko 2022) However, in some instances where this seedling together with other species were raised from the Ministry of Environment headquarters in Abuja and distributed to various states for propagation, regrettably majority of the seedling are usually not well managed due to drought and other biotic factors. In some instances, the seedlings are distributed to farmers and the locals for regeneration. Yet it has not been successful due to a lack of incentives, nursery materials, and technical knowledge. Even when the seedlings grow, they are constrained by the vulnerability of young seedlings to wildfires, pests, trampling of animals, and adverse climatic conditions, preventing most of them from crossing the first years of life (Kossi et al. 2021). Therefore, it is recommended that stricter conservation measures such as a ban on logging and export of endangered species should be enacted and enforced by the government of Nigeria at all levels to allow for the regeneration of the juvenile species. Similarly, conservation education through sensitization and participatory local interaction may help the locals understand the critical state of the species is imperative because universal education is key to biodiversity conservation (Bello et al. 2019).
Securidaca longepedunculata Fresen
Family: Polygalaceae
Common names: violet tree, fibre tree (Eng.)
Local names: Úúwár máágúngúnà or Sányáá (Hausa), aalali (Fulfulde)
Securidaca longipedunculata is a deciduous or semi-deciduous shrub or small tree that grows to 12 m tall, and has a rough bark, yielding a white gum when peeled and the young branches softly are tomentose (Hutchinson and Dalziel 1954-1972). It is one of the commonest and most widely spread African shrubs, ranging over the whole of Tropical Africa, and well adapted (Hutchinson 1921). Securidaca longipedunculata has a long history of use in Nigeria (Abubakar et al., 2022) and other African countries in various traditional medicines preparations to treat various sexually transmitted infections such as hernias, coughs, fever, ascariasis, constipation, headaches, rheumatism, stomach ache, malaria, tuberculosis, pain, epilepsy, pneumonia, skin infections, and it is also used as an aphrodisiac for men (Muazu and Kaita 2008; Mongalo et al. 2015; Abubakar et al. 2019; Shemishere et al. 2020). This plant is threatened by numerous anthropogenic disturbances such as agriculture, bushfires, droughts, grazing, deforestation, climate change, and overexploitation (Abubakar et al. 2018). Of all these threats, over-harvesting was recorded to be the major threat confronting this species because roots are the target for people using this plant, which makes it difficult for the plant to survive constant harvesting (Abubakar et al. 2018; Lijalem and Feyissa 2020). This unsustainable method of harvesting has decimated S. longipedunculata which was reported to have a wide distribution range. This species is currently rare and is currently known to exist in a few localities with a small subpopulation. The population is decreasing with a small number of mature individuals; the extent of occurrence was estimated to be < 100 km² and thus S. longipedunculata is assessed as CR. This agrees with the previous assessment of Bello et al. (2019).
CR= Critically Endangered, B1ab (ii, ii, iv); D1
Recommended Conservation actions: Securidaca longipedunculata is protected under provincial and national legislation in many countries (Abubakar et al. 2018). In Nigeria, this species is not protected by any law, despite that it is largely collected and ranked among the most traded medicinal plants in Africa and Nigeria inclusive (Abubakar et al. 2018). S. longipedunculata have high seed dormancy and low germination rate (Abubakar et al., 2018). Therefore, it is recommended that this species should be domesticated and inculcated into agro-forestry systems of the country.
Sterculia setigera Delile
Family: Malvaceae
Common name: karaya gum Tree
Local name: Kûkkúúkì (Hausa), gorko ɓokki (Fulfulde)
Sterculia setigera is a deciduous tree up to 16 m high, with a spreading open crown and large twisted branches, the bark is grey to purple in colour and flakes to reveal a greenish-yellow smooth bark beneath (Hutchison and Dalziel 1954). If the bark is cut it reveals a red inside and exudes a white gum and watery sap. The leaves are simple, alternate, 6-20 cm long and 6-20 cm wide, with 3-5 triangular lobes. They are covered with stellate hairs on both sides, but more densely on the underside. The flowers are unisexual, apetalous, and pedicellate, with a 5-lobed conical calyx. They are green or yellowish in colour, and striped or tinged red inside (Burkhil 2004). S. setigera is widely distributed in the Sahelo-Sudan and Guinea savanna zones of Tropical Africa (Hutchison and Dalziel 1954). This plant is regarded as one of the most important trees in Sub-Saharan Africa because of its multifunctional uses and products. The tree produces a water-soluble gum commonly known as gum karaya or Gum Sterculia (Tadesse et al. 2009). This gum is highly valuable as it can be used in cooking as an emulsifier, stabilizer, and viscosifier; and medically it is used as a laxative, diuretic, and tranquilizer, and technically as an adhesive and for glazing pottery (Sacandé et al. 2007; Atakpama et al. 2017; López-Franco et al. 2020., Mudgil and Barak 2021; Prasad et al. 2022). Ethnobotanically, the bark of S. setigera is used for rope making and the bark sap can be made into a refreshing drink (Burkhil, 2004, Sacandé et l. 2007). While traditionally the bark is also used to treat snake bites, leprosy, syphilis, coughs, bronchitis, rickets, and insanity (Burkhill 1985; 1994). Despite its numerous uses and socioeconomic value, Sterculia setigera is threatened by significant anthropogenic pressures mainly overexploitation of gum and other organs harvesting, annual bushfire, grazing, and agriculture practices which often lead to induce mortality and impeding regeneration capacity (Atakpama et al. 2017) and thus exacerbated by impact of climate change. However, currently, Sterculia setigera is rarely seen in its area of distribution. The population size is decreasing with a few number of mature individuals recorded in each population. It suffices to say that this species has greatly been decimated leading to local extinction in some habitats that they were previously reported (Hutchison and Dalziel 1927-1954).
Based on the information above, we thus assessed Sterculia setigera as CR. This is consistent with Bello et al., (2019), who provisionally reported this species as CR; while globally this species has been reported as LC on the IUCN Red List of threatened species (BGCI 2020).
CR= Critically Endangered, B1ab (ii, ii, v)
Recommended conservation actions: Further monitoring of the species and sound knowledge of the species' biology and ecological requirements which encompass its regeneration status, are needed for sustainable management of the species. Also, the integration of S. setigera in the agroforestry systems is another approach to conserving this species (Atakpama et al. 2017).
Terminalia habeensis (Aubrév. ex Keay) Gere & Boatwr
Family: Combretaceae
Local names: Lallen Giwa(Hausa)
Terminalia habeensis is a straggling shrub or small, twisted tree with a dense, rounded crown; bark fibrous, flaking off even in young branches, grey-brown, inner bark pale brown; branchlets slightly hairy, grey-brown (Oyen 2010). The species is found in the Guinea savanna of northern Nigeria, particularly in the Yankari game reserve (Hutchison and Dalziel 1954). And in some sub-Saharan African countries such as Mali, Ghana, and Benin (Geerling 1984). While fire has been a threat to many savanna plants, Terminalia habeensis is apparently fire-tender because it occurs in places where it is protected from fire, such as on rocky hills (Geerling 1984; Govaerts et al. 2021). Terminalia habeensis is used traditionally in treating malaria, stomach aches, and cancer, as an aphrodisiac and in the destruction of tumours (Muhammad 2014; Aliyu et al. 2018). Terminalia habeensis is only known from the Yankari Game Reserve (YGR) in Nigeria. Based on current evidence and field observation, it is estimated that the extent of occurrence of T. habeensis is 2,244 km2 which is equal to the area of occupancy. Though YGR is a protected area, the surrounding communities have a high human population density with active farming and grazing activities. The habitat outside the protected area has been fragmented and destroyed. We did not record even a single species of T. habeensis outside the protected area. However, with the escalating population in the surrounding communities, it is envisioned that people would invade the reserve in future for farming purposes, resulting in major threats to this species. On the basis of the information available, T. habeensis thus appears extremely vulnerable to stochastic and other changes to its habitat. Based on the single location of T. habeensis, we therefore assessed this species as Critically Endangered, CR B1+2ab (iii). Conversely T. habeensis has previously been assessed over three decades ago as Endangered (EN) by IUCN (Hawthorne 1998).
CR= Critically Endangered CRB1+2ab (iii)
Recommended Conservation actions: Further survey in the country to identify more population and understand the distribution trend, especially outside the protected areas.
Terminalia macroptera Guill. & Perr.
Family: Combretaceae
Local names: Kandare (Hausa), kuula-hi/je (Fulfulde)
Terminalia macroptera is a tree about 13 m high, with short bole, thick black, and deeply fissured bark (Burkhil, 1985). Leaves are large, bright green, bark black fissured, and flowers white, and glabrous outside (POWO, 2022). The tree usually grows in moist wooded savanna habitats of West Africa and occasionally extends to Sudan (Burkhil, 1985). Traditionally the bark, leaves, and roots are widely used in traditional medicine for diverse ailments such as diarrhea, dysentery, tu- berculosis, edema, gastritis, cough, hepatitis, ringworm, hepatitis and rheumatism, as well as a febrifuge, a fortifier, and against women's infertility (Burkhil 1985-2004; Kola-Mustapha et al. 2023). The leaves are also used in gastritis, colic, and hypertension, against fever, lepra, and tuberculosis (Pham et al., 2011). Timber from this species has been reported to be strong and resistant to insect attack, and thus popular in the international market; as they are used for building and furniture (Pham et al. 201; Asase et al. 2012; Jennifer et al. 2014). Terminalia genus in Nigeria has almost cosmopolitan distribution as they are widely distributed in nearly all the various habitats in the country. T. macroptera is threatened by excessive cutting of the wood for the production of charcoal mostly used by bakers and blacksmiths and also fuel wood for cooking. Furthermore, the cutting of saplings of this tree species for making farm implements handle, and for staking of yam farmers. Sadly, habitat fragmentation resulting from unsustainable agricultural intensification, grazing, and indiscriminate logging exacerbated by climate change is another threat confronting this species.
These activities put together have decimated this species, and we observed a decreasing population with few mature individuals throughout the areas visited. The estimated extent of occurrence is 4800 km2 and the estimated area of occupancy is 100 km2. Based on the above criterion, Terminalia macroptera is thus assessed as EN.
EN= B1ab (ii, iii, v) + C2ab (i); D
Recommended conservation actions: The tree has long been recommended as a suitable species for reforestation, especially where it was formerly abundant (Burkhil, 1985-2004). Therefore, massive propagation of the seedlings and donating to the locals for cultivation is highly recommended.
Terminalia schimperiana Hochst
Family: Combretaceae
Local names: Fárín báushèè (Hausa)
Terminalia schimperiana is a small deciduous tree up to 7-15 m which is exclusively endemic to savanna areas of West Tropical Africa to Ethiopia and North West Tanzania (POWO, 2022). The bark is dark grey and deeply fissured and the leaves are tufted at the end of branches, spirally arranged, long oval 15-24 cm long, densely hairy when young, later hairy on veins and some other hairs (Hutchison and Dalziel 1927-1954; Keay et al., 1989). The root and root bark is applied for the treatment of burns, wounds, and skin diseases, while root powder is used for epilepsy treatment, and root decoctions are used for malaria, hepatitis, and cough treatment (Burkhil 1985; 2004; Awotunde et al.,2019). The bark is locally used to treat wounds, while the twigs may be chewed to promote oral hygiene in a form of dental care; and are also used as a laxative, to treat catarrh, as a tonic and aphrodisiac (Awotunde et al. 2019; Khan et al. 2019). T. schimperiana is one of the more frequently used trees as a resource of fuelwood and timber. In the NSZ of the country, truckloads of T. schimperiana and T. macroptera are harvested in large quantities for commercial fuel wood and charcoal production. These duos are locally referred to as “itacen baushe” in the Hausa language meaning wood from Terminalia. Wood from this is regarded as one of the best fuel wood for charcoal and are traded even outside where they are found. During our fieldwork, we encountered a truckload of Terminalia spp and Prosopis africana from Adamawa state being taken to Gombe state for the production of charcoal for bread bakery.
This incessant logging, coupled with excessive grazing, and agricultural expansion leading to habitat fragmentation and climate change are the major threats confronting this species, thus imperiling the existence of this species. The population size of this species is fragmented, and there is a sharp decrease in the population size, with a majorly small number of mature individuals. The estimated extent of occurrence is 18 000 km2 and the estimated area of occupancy is 200 km2.
EN= Endangered B2ab (ii, iii, v)
Recommended Conservation actions: The tree has long been recommended as a suitable species for reforestation, especially where it was formerly abundant (Burkhil, 1985; 2004). Therefore, massive propagation of the seedlings and donating to the locals for cultivation is highly recommended.
Name: Uapaca togoensis Pax
Family: Phyllanthaceae
Local names: Kàfáffágóó (Hausa) bakureehi (Fulfulde)
Uapaca togoensis is a typical savanna tree that grows up to 15-20 m tall and has a rounded crown and pendulous branchlets, but sometimes shrubby; bark pale grey to dark brown, scaly, finely reticulate; young stems glabrous to densely pubescent hairy or tomentose (Hutchison and Dalziel 1954; POWO 2022). Uapaca togoensis native range is W. Tropical Africa to S. Chad and N. Angola (POWO 2022).
U. togoensis is a medicinal plant used in sub-Saharan Africa as an emetic preparation and a lotion for skin disorders, and the leaves, fruits, and bark are also used as a remedy for pneumonia, cough, fever, rheumatism, vomiting, epilepsy (Burkhil 1985; 2004; Seukep et al. 2016).
This species is not harvested for medicinal uses where it occurs, and it is not logged for timber except sporadically for firewood. The charcoal dealers verbally confirmed to us that the tree is soft and does not make good fuel wood. Uapaca togoensis is abundant and common where it occurs especially in Gashaka Gumti National Park, which is Nigeria’s largest national park (6731 km2) where this species is dominant in the savanna zone of the park (Nodza et al. 2022). U. togoensis is also abundant in KLNP (Tang and Adesina 2022), the estimated extent of occurrence is > 40 000 km2 and the estimated area of occupancy is 6000 km2. Uapaca togoensis is thus assessed as LC.
LC= Least Concern
Vitellaria paradoxa C.F.Gaertn.
Family: Sapotaceae
Common name: Shea Butter Tree
Common names: Kadanya (Hausa), kaareeje (Fulfulde)
Vitellaria paradoxa (Shea) is a small to medium-sized tree that grows up to 25 m high with a much-branched, dense, spreading, round to hemispherical crown (Orwa et al. 2009). The leaves are tufted, in dense clusters, spirally arranged at the ends of stout twigs (Hutchinson and Dalziel 1954–1972; Keay et al. 1989). The tree possesses a conspicuously thick bark, longitudinally and deeply fissured (Choungo Nguekeng et al. 2021). Vitellaria paradoxa is indigenously distributed in the Guinea and Sudan savanna zones from Senegal to Sudan and western Ethiopia and Uganda, growing in 21 countries (Orwa et al. 2009; Burkhil 2004). In Nigeria, Shea grows in the wild in many states including Niger, Nasarawa, Kebbi, Kwara, Kogi, Adamawa, Benue, Edo, Kastina, Plateau, Sokoto, Zamfara, Taraba, Borno and Oyo (Akparanta et al. 2017).
Shea is regarded as one of the multipurpose trees in the savanna zone of Africa, where rural communities depend on the SShea products for food, medicine, and income (Teketay et al., 2003., Teklehaimanot 2004; Okiror et al. 2012; Jasaw et al. 2015; Maanikuu Peker 2017; Aleza et al. 2018; Choungo Nguekeng et al. 2021; Nuhu et al. 2021; Ojo et al. 2021 Gbemavo et al. 2022and Sodimu et al. 2022). Despite having a wide distribution range, this species is under numerous threats, especially overexploitation for charcoal production, fuel wood, mortar/pestle, and hoe handle, land use patterns, bush fires, prolonged droughts, scarcity of Shea hybrids, long gestation period and rapid human population growth (Buyinza and Okullo 2015; Aderibigbe et al. 2017; Garba and Muhammad-Lawal, 2020). Other threats include attacks by insects and parasitic plants, which often lead to the death of the tree or drive the species into local extinction (N'Djolossè et al. 2012; Houehanou et al. 2013; Gbemavo et al. 2022).
Due to its economic value, the Federal Government of Nigeria has established a tree breeding centre for Shea species in Bida Niger state (Ugese et al. 2010; Mohammed et al. 2017; Koloche et al. 2016 and 2021). Even farmers in this region have also attempted to domesticate this species as an agroforestry tree. This has been constrained by climatic conditions, characterized by a long dry season, which could affect the regeneration of young seedlings. Shea trees have slow growth, long juvenile phases, and large yield variability (Koloche et al. 2021) are other impediments. Shea tree is rare outside protected areas.
The population size is constantly decreasing with a small number of mature individuals, with the estimated extent of occurrence being> 20 000 km2 and the estimated area of occupancy being < 500 km2. Vitellaria paradoxa is thus assessed as EN.
The conservation status of V. paradoxa is further confirmed by being included on the IUCN Red List of Threatened Species (IUCN 1998), where the tree was assessed as vulnerable (VU).
EN= Endangered, B2ab (ii, ii, v)
Recommended conservation actions:
Since Shea seed has a long gestation period, Shea hybrid with a much lesser growth period should be produced and seedlings should be distributed to farmers, which in turn will promote planting and curtail the reliance on natural regeneration (Garba and Muhammad-Lawal 2020).
Shea tree is not protected by any national legislation or jurisdiction in Nigeria. Most of the protection of Shea comes from the community effort, owing to the species' socioeconomic importance to the locals. Therefore, government should enact stringent bylaws on banning cutting Shea trees except those with undesirable forms, usually the smallest in size, or those that are unproductive, and collecting only Shea fruits that have fallen as reported from Uganda (Acema et al. 2021)