Ngel Nyaki Forest Reserve Research Articles

Assessment of Beetles Diversity and Abundance in Forest Edge and Grassland Ecosystems of Ngel-Nyaki Forest Reserve

This survey of beetles abundance and diversity was conducted at the Nigerian Montane Forest Project, Ngel-Nyaki Forest Reserve (NMFP). The study aimed to assess the abundance and diversity of beetles at the Ngel-Nyaki Forest Reserve located at Latitude 7°05′ N and Longitude 11°04′ E. It was carried out for one month from September to October 2021. Stratified sampling method was used to divide the study location into two major habitats; forest fragment and grassland and subsequently plots. A total of 200m line transect was established each on the selected habitat types. Pitfall traps were placed at 50m intervals along a 200m transect for the selected habitats. Hand-pick was adopted for beetle collection along the line transects. Sample collections were carried out in the morning and in the evening between the hours of 6 am and 8pm respectively. A total of 233 beetles were collected consisting of 24 species. The highest species diversity was recorded in the grassland (H’= 2.65). The relative Abundance is 0.69 and 0.3 from the 2 habitats. The Abundance of beetles in the forest reserve contributes to the ecosystem of the forest.

Assessment of Bees’ Diversity within Ngel-Nyaki Forest Reserve at Taraba State, Nigeria

A field survey was conducted in Ngel-Nyaki Forest Reserve to assess the diversity of bees within the Reserve. Two methods of sampling techniques were used to sample bee species, opportunistic sampling and systematic sweep netting. Opportunistic sampling method was applied by sweep netting bees along 100 m plot where flowering plants were blooming. Collection was conducted by a single collector using an active search by walking randomly around the plot observing flowering plants and searching for bees foraging on the flowers then a sweep net was used for capturing bees. Sweep netting was conducted, line transect established within the plots for two hours, from 6:00am to 11:00am spending 20 minutes in each plot considering when the weather is conducive for bees’ activity. This was done using entomological sweep net. Bees captured were killed in a killing bottle containing 70% ethanol. Specimens were pinned on a board and unique codes were assigned to each species before identification. Bees were identified to species level by using published systematic keys, Bees field guide and use of online materials. All data were computed using Microsoft® Excel® 2016 and percentage abundance composition of bees were calculated.575 bees spreading across 3 families and 12 species were sampled. The most abundant species was the honey bee (Apismellifera) (245; 42.53%),followed by memic bee (Megachile sp.)(89;15.45%),and the least was leafcutter bee(Osmiasp.) (2;0.35%). In terms of diversity by species, Shannon Diversity Index (H) and Shannon Equitability Index (EH) were 1.694893 and 0.736083respectively while diversity by plots using Shannon Diversity Index (H) and Shannon Equitability Index (EH) were 1.750688 and 0.977078 respectively. This study therefore, brings to the fore the diversity of bees within Ngel-Nyaki Forest Reserve and underline the need for sustainable actions to be taken to conserve beneficial rare species while managing the abundant ones.

Impacts of trees species and functional traits on birds visitation in a Nigerian montane forest: Implications for conservation: Trees Functional Traits and Birds Visitation

Birds provide ecosystem services that play crucial role in maintaining forest ecosystems. However, the knowledge of the relationship between different bird assemblages and different forest types is still scanty. We analyzed the impacts of different tree species of different functional traits on visitation preferences by birds in Ngel Nyaki Forest Reserve, Nigeria (7°30′N, 11°30′E). We monitored visitation of different bird species to trees using the point-count method. A total of 32 bird species were recorded. Must of bird species (28 species) were insectivores, while four species are frugivores. The rate of visitation of different bird species differs significantly among the different tree species. Correlation analyses showed that the frequency of birds’ visits depend on abundance of individuals of a tree species. However, some of the tree species are more frequently visited by different species of birds, while other trees are peculiar in terms of visitation preferences by some of the bird species. More important tree species as the frequency of birds’ visitation is concern include M. lanceolata (205), P. fulva (134), and B. speciosa (113). Trees that were visited by the highest number of species of birds include B. speciosa (28), M. lanceolata (20), and T. aurentalis (19). There was also a positive effect of trees' functional traits on the total number of birds’ visits, but there was no correlation between the trees' functional traits with the abundance of individual bird species visitation. We hypothesized that small morphological differences among trees will have no impact on bird's visitation as found in this study. These results and interpretations have implications for sustainable management and conservation of montane forest and possibly elsewhere.

Species Richness and Diversity of Land Snails in Ngel-Nyaki Forest Reserve, Mambilla Plateau, Taraba State Nigeria

Species Richness and Diversity of Land Snails in Ngel-Nyaki Forest Reserve, Mambilla Plateau, Taraba State Nigeria

Afromontane Forest Diversity and the Role of Grassland-Forest Transition in Tree Species Distribution

Local factors can play an important role in defining tree species distributions in species rich tropical forests. To what extent the same applies to relatively small, species poor West African montane forests is unknown. Here, forests survive in a grassland matrix and fire has played a key role in their spatial and temporal dynamics since the Miocene. To what extent these dynamics influence local species distributions, as compared with other environmental variables such as altitude and moisture remain unknown. Here, we use data from the 20.28 ha montane forest plot in Ngel Nyaki Forest Reserve, South-East Nigeria to explore these questions. The plot features a gradient from grassland to core forest, with significant edges. Within the plot, we determined tree stand structure and species diversity and identified all trees ≥1 cm in diameter. We recorded species guild (pioneer vs. shade tolerant), seed size, and dispersal mode. We analyzed and identified to what extent species showed a preference for forest edges/grasslands or core forest. Similarly, we looked for associations with elevation, distance to streams and forest versus grassland. We recorded 41,031 individuals belonging to 105 morphospecies in 87 genera and 47 families. Around 40% of all tree species, and 50% of the abundant species, showed a clear preference for either the edge/grassland habitat or the forest core. However, we found no obvious association between species guild, seed size or dispersal mode, and distance to edge, so what leads to this sorting remains unclear. Few species distributions were influenced by distance to streams or altitude.

Perception of predation risk by African giant pouched rats (Cricetomys sp. nov) is higher in forest-edge microhabitats

How rodents perceive predation risk may alter their seed foraging behaviour and therefore potentially influence the recruitment of tree species. In this study we used two methods to investigate the effect of predation risk on habitat use by the African giant pouched rat (Cricetomys sp. nov) in Ngel Nyaki forest reserve, Nigeria. The first method was ‘giving up density’ (GUD), an index of perceived risk of predation at an artificial food patch, and the second was the ‘spool-and-line’ approach, whereby unravelling spools attached to rodent bodies are used to trace their tracks. For our GUD experiment, we chose four major sites in the forest; two representative of core habitat and two at the forest edge. Additionally, three characteristic microsites were used in the GUD experiment: dense understory, open understory and near-burrows. We hypothesised that GUDs would be lower on every succeeding observation day as rats learn to use the food patches, higher GUDs would be observed in the forest edges and open microsites, and rats would show preference for the microhabitats with least exposure to potential predators. In support of our first hypothesis, we found that GUDs were highest on the first experimental nights of every session. We also found that GUDs in the forest edges were higher than GUDs in the forest core. Lower GUDs were observed close to the rat burrows and in dense understory microsites, even though these differences were not statistically significant. Tracking of rat movements using the spool-and-line method overall revealed an even use across microhabitats, with a weak preference for those with logs, dense understory or exposed ground. Overall, our results suggest that vegetation density on a microhabitat scale has little or no effect on the perception of predation risk by African giant pouched rats.

Macrofungi composition and diversity on deadwood in Ngel Nyaki forest reserve, Mambilla Plateau, Nigeria

Macrofungi are extensive in diversity and play an essential role in sustaining ecosystems. However, the size and quality of their habitat is decreasing and extinction threatens the remaining 95 % of the world’s undiscovered fungal species. This study was carried out to document the diversity and composition of macrofungi in Ngel Nyaki Montane Forest Reserve. A total of seventy-two (72) wood decomposing fungi were identified belonging to 8 classes, 12 Orders and 27 Families. The most abundant species was Trichoglossum hirsutum (Pers). Boud with 23.49% relative frequency of occurrence followed by Russulax erampelina (7.23%), Hemimycena candida (Bres) Singer (5.42%), Termitomyces eurhizus (Berk.) Heim (4.82%), Pleurotus pulmonarius (Fr.) Quel (4.22%) and Ganoderma sp 1 (3.61%). Thirty-eight (52.77%) of the 72 species were rare, as they were seen and collected once during the survey. Eight (8) different fruiting body forms were encountered. Most of the macrofungi were the gilled fungi (Agarics) with 39 species, followed by the Polypores with 21 species, while cup fungi, slime mould and coral fungi were represented in the whole collection by a single species each. Macrofungi diversity varied significantly across pieces of deadwood with wood in later stages of decay having the highest macrofungi diversity. The study documents the first checklist of macrofungi in Nigeria’s rarest forest landscape. Keywords: Macrofungi, Composition, Diversity, Ngel Nyaki, Mambilla Plateau

Conservation genetics of two threatened frogs from the Mambilla highlands, Nigeria.

Amphibians are the vertebrate group with the highest number of species threatened with extinction, and habitat loss and fragmentation are considered to be among the leading causes of their declines and extinctions. Little is known of the population biology of amphibian species inhabiting montane forests in Central and West Africa, where anthropogenic activities such as farming and cattle raising are major threats to native biodiversity. We used Amplified Fragment Length Polymorphisms (AFLPs) to assess the population genetic structure of two poorly known species, Cardioglossa schioetzi and Leptodactylodon bicolor (both in the Arthroleptidae), in and around Ngel Nyaki Forest Reserve on the Mambilla Plateau in eastern Nigeria. The landscape comprises continuous forest on steep slopes and small riparian forest fragments in a grassland matrix. While increased fragmentation is well documented for these and other forests in the mountains of Cameroon and Nigeria over the past century, there are no previous assessments of the impact of forest fragmentation on montane amphibian populations in this region. Our estimates of genetic diversity are similar across populations within each species with levels of heterozygosity values consistent with local population declines. Except for a pair of populations (C. schioetzi) we did not observe genetic differentiation between forest and riparian forest fragment populations, nor across sites within continuous forest (L. bicolor). Our results demonstrate recent gene flow between forest fragments and the adjacent protected forests and suggest that small forest corridors connecting these may lessen the genetic consequences of at least 30 years of intense and severe fragmentation in Ngel Nyaki.

Habitat fragmentation and its implications for Endangered chimpanzeePan troglodytesconservation

AbstractTaraba State, Nigeria, is an important conservation site for the Endangered Nigeria–Cameroon chimpanzeePan troglodytes ellioti. Gashaka Gumti National Park, Nigeria's largest national park and home to potentially the largest contiguous population of the Nigeria–Cameroon chimpanzee, spans a significant portion of the eastern sector of Taraba and the adjoining Adamawa State. South of the Park, Ngel Nyaki Forest Reserve comprises two forest fragments and holds a small population of chimpanzees. We investigated the existence of patterns in population structure and dispersal within this region, using microsatellite loci extracted from non-invasive sources of DNA. Our results indicate that dispersal and thus gene flow between the groups of chimpanzees at the Park and Reserve is limited, at least more so than it is within the Park, and we identified a biased sex ratio at the Reserve, forewarning of potential conservation concerns in relation to demographic and genetic stochasticity. We discuss conservation actions that may be applicable to sustaining the population within Ngel Nyaki Forest Reserve.

Dietary preferences of a submontane population of the rare Nigerian-Cameroon chimpanzee (Pan troglodytes ellioti) in Ngel Nyaki Forest Reserve, Nigeria.

We investigated the dietary preferences of chimpanzees residing in a Nigerian submontane forest using a combination of fecal analysis, observations of feeding remains, evidence from feeding tools and fruiting phenological data between April 2010 and March 2011. A total of 495 fecal samples were collected in which 52 fruit taxa were identified as having being consumed by chimpanzees, including 22 identified to species level and two identified to genus level. Ficus (seven species) was the most common seed genus identified, occurring in 61.2% of all fecal samples. Based on fecal analysis and phenological data, Ngel Nyaki chimpanzees do not solely consume fruits based on their availability within the habitat; while the proportion of fruit consumed did reflect the relative availability of fruit in the forest for some fruit species, Ficus was a preferred fruit even when scarce. In contrast, the proportion consumed of other fruit species was low relative to the abundance of their fruit available in the forest. Our results from the Rank Preference Index (RPI) suggest that relative preferences in fruit are seasonal. We discuss the role of Ficus in the diet of chimpanzees in Ngel Nyaki Forest Reserve.

Spatial distribution of turaco-preferred food plants in Ngel Nyaki Forest Reserve, Mambilla Plateau, Taraba State, Nigeria

The relative distribution was investigated of turaco-preferred food plants in the main forest and the forest fragments of Ngel Nyaki Forest Reserve in Taraba State, Nigeria. Data collection was carried out in three sections within the forest reserve and these include (i) forest fragment, (ii) within the main forest and (iii) the boundary area of the main forest. Ten plots with size of 25 m × 25 m were laid at an interval of 50 m in each of the three selected sites making a total of 30 plots for the sampling of turaco-preferred fruiting plant species. The numbers of fruiting tree species identified were 22, 25 and 24, and out of these only seven (31.8%), eight (32%) and six (25%) were preferred by turacos in the forest fragment, within the main forest and the boundary area of the main forest, respectively. The preferred fruiting plant species in the forest fragment was Syzygium guineense (48.6%), in the boundary area of the main forest was Ficus sp. (13.3%) and within the main forest was Polyscias fulva (3.9%). Many of the fruiting tree species in the boundary area and within the main forest were not preferred by turacos. There is a need for effective pro-conservative measures aimed at preserving the remaining forest patches (especially the forest fragment) of the reserve.

Community-based Forest Resources Management in Nigeria: Case study of Ngel Nyaki Forest Reserve, Mambilla Plateau, Taraba State, Nigeria

In Nigeria, human communities are found within or beside forest ecosystems, depending onthese ecosystems for survival. Their forest exploitation is considered a threat to conservation efforts,leading to constant conflicts between Government, law enforcement agencies and the communities. Thebest solution is a win-win system of participatory community-based forest resources management, inwhich the communities are regarded as stakeholders rather than as threats. This paper explains theadoption of this approach in Ngel Nyaki Forest Reserve, Mambilla Plateau, where the communities weretrained in establishment and management of forest plantations with readily available market for theirtimber; employment for some of the community youths as well as community development projects.This paper calls for the adoption of this system in other protected areas in Nigeria, while theGovernment should provide basic amenities for the communities as alternatives to those forest products.Keywords: Community-based forest management, Ngel Nyaki Forest Reserve, Protected areas, Nigeria.

Dependence on sunbird pollination for fruit set in three West African montane mistletoe species

Abstract:Theory predicts that not all plant species will be equally affected by disruption to their pollinator mutualisms because traits such as breeding system and mutualism strength can affect their response. We investigated these traits in three species of Afromontane mistletoe Globimetula braunii, Agelanthus brunneus and A. djurensis in Ngel Nyaki Forest Reserve, Nigeria, to test whether the traits were reliable indicators of relative reproductive success and could be used to predict relative vulnerability to pollinator loss. For each mistletoe species, insect and bird visitors were identified during a 160–240-min observation period of 4–10 plants and their roles in flower opening and fruit set were investigated using exclusion experiments applied to 250–500 flowers. We found that all three mistletoes are self-compatible but not capable of autonomous self-fertilization. The pollinator assemblage comprised four species of sunbird (Cyanomitris spp., Cinnyris spp.) and a small social wasp (Vespinae). None of the mistletoes requires birds for flower opening: G. braunii flowers self-opened in the absence of pollinators, whereas insects opened both Agelanthus spp. Irrespective of flower opening, each mistletoe species requires sunbirds for effective pollination and fruit set. Only G. braunii demonstrated pollen limitation (pollen limitation index = 0.504) which may be an early indication of mutualism breakdown. We suggest that mistletoes be considered as indicators of habitat condition and functioning within Afromontane forest ecosystems.

A population estimate of the Endangered chimpanzee Pan troglodytes vellerosus in a Nigerian montane forest: implications for conservation

Pan troglodytes vellerosus, the Nigerian-Cameroon chimpanzee, is the most recently recognized chimpanzee subspecies and is categorized as Endangered on the IUCN Red List. Current estimates, based on a range of sources, suggest the total number of individuals to be between 5,000–8,000. This study used a transect survey to estimate the population of P. t. vellerosus within the Nigerian submontane forest of Ngel Nyaki Forest Reserve, in Taraba State. The forest is an isolated fragment of c. 7.5 km2. Total nest building population size (n = 12.5) and population density (1.67 weaned chimpanzees km-2) were estimated from the number of nests observed along line transects. The maximum nest-group size (n = 11) suggests that this population comprises a single community. The low estimated population numbers within Ngel Nyaki forest, compounded by the forest's isolated location, highlight the urgent need for conservation action.