African Walnut Research Articles

Phytochemical and Proximate Compositions of Tetracarpidium Conophorum [African Walnut] Seeds

Phytochemical and Proximate Compositions of Tetracarpidium Conophorum [African Walnut] Seeds

Physical properties of the African walnut (Tetracarpidium conophorum) from Nigeria

AbstractIn this research about 1,700 samples of the African walnut (Tetracarpidium conophorum) were measured for their axial dimensions, mass, geometric mean, sphericity index, surface area, aspect ratios, angle of repose on steel, wood and glass, porosity, bulk and true density of the nut, kernel and shell at five moisture levels and three size ranges. Various equations linking the nut moisture content with other physical properties for nut and kernel were established using regression models. The studies showed that at initial moisture content of 28.2% w.b, the African wild walnut fall mostly within the mass (m) range of 5.5 ≤ m ≤ 6.5 g with shell thicknes of 0. 135 ± 0.04 cm, kernel mass of 4.22 ± 0.26 g, kernel moisture content of 28.9% w.b, porosity of 45%, nut true density of 0.815 g/cm3, nut bulk density of 0.45 g/cm3, nut aspect ratio of 76% and nut surface area of 15.41 cm2. This various properties are affected by increase in moisture contents and change in nut mass.

Interspecific Comparisons with Chloroplast SSR Loci Reveal Limited Genetic Variation in Nigerian Montane Forests: A Study onCordia Millenii(West African Cordia),Entandrophragma Angolense(Tiama Mahogany), andLovoa Trichilioides(African Walnut)

The montane forests of south-eastern Nigeria are of immense conservation value due to their high levels of biodiversity and endemism. Yet despite increasing anthropogenic disturbance and forest fragmentation, little is known about the genetics of resident tree populations. We used a set of conserved chloroplast simple sequence repeat (SSR) primers to quantify and directly compare genetic diversity in three tree species: Cordia millenii, West African Cordia; Entandrophragma angolense, tiama mahogany; and Lovoa trichilioides, African walnut, within a single montane forest. Additionally, we assessed the diversity of West African Cordia between forests at a local and regional scale. Results indicate that for our focal loci, in all three species, there is a general lack of chloroplast genetic diversity. Our study is particularly relevant because it considers genetic diversity among multiple tree species simultaneously. This work represents the first study of its kind in the region, and will pioneer the way for future conservation genetic studies in montane Nigeria.

Effects of Cooking and Germination on Physiochemical Properties and Sensory Attributes of African Walnut (<i>Tetracarpidium conophorum</i>)

Effect of cooking and germination on physiochemical and sensory attributes of African walnut were investigated. Result proved that the protein (14.90%) carbohydrates (15.39%) fat (45.84%) ash (3.5%) and fibre (1.17%) contents of the raw samples were increased by germination but subsequently decreased as germination progresses. Cooking was found to be more effective in reduction of antinutrients than germination thereby leading to enhanced bioavailability of most essential minerals (calcium, magnesium, sodium, phosphorus etc). Results also indicate significant (P<0.05) improvement on the functional properties (water absorption capacity, oil absorption capacity, ) of the raw sample by cooking and germination. Evaluation of sensory attributes showed that cooked walnut was most preferred to germinated and boiled walnut in terms of taste, after taste and general acceptability.

Effect of Fermentation and Heat Treatment on the Nutrient and Antinutrient Composition of African Walnut (Tetracarpidium conophorum)

Effect of Fermentation and Heat Treatment on the Nutrient and Antinutrient Composition of African Walnut (Tetracarpidium conophorum)

Effects of postharvest storage and processing techniques on the main fatty acids in the profile of oil extracted from African Walnut (Tetracarpidium conophorum Mull. Arg.)

African Walnut (Tetracarpidium conophorum Mull. Arg.) is a perennial climber which grows in the western and central regions of Africa. The nuts are processed by boiling and roasting and are sold within 1–5 days to consumers through the open market system. During processing, storage and distribution, the nuts are typically exposed to high temperatures raising concerns over nutrient quality and safety. Although African walnut, like several other nuts, contains high amount of oil, there is no study reporting on how the common processing methods (boiling and roasting) affect the fatty acid profile. Nut samples (n=702) at both early and late maturity were harvested and stored at 5°C. Randomized sampling was done (0, 10 and 20 days) and nuts grouped according to treatments (boiling, roasting, unprocessed). Nuts were then held for 3 and 7 days at either 25°C or 37°C to simulate normal retail practices. Oil was extracted and analysed as fatty acid methyl esters using gas chromatography flame ionization detection and gas chromatography coupled mass spectrometry. Retention times were compared with known standards. Results indicated the presence of C16:0, C18:0, C18:1 cis-9, C18:2, cis-9, 12, C20:0, C18:3 with C18:3 being the most abundant (1.1–8.2mgg−1 dry matter). In general, postharvest storage at 25°C or 37°C for 3 or 7 days after boiling and roasting significantly increased concentrations of the fatty acids (>50%) in nuts stored for 10 days compared to unprocessed. Current processing methods and retail storage practices improved concentrations of the fatty acids in African walnut stored up to 10 days at 5°C.

Amino acid profile of raw and boiled seeds of african walnut (<i>Plukenetia conophorum</i> Muell Arg.) From south-eastern Nigeria

Seeds of African Walnut (Plukenetia conophorum Muell Arg.) obtained from four (4) states – Enugu, Anambra, Abia, Rivers – in south-eastern Nigeria were assayed for amino acid contents of the raw and cooked seeds using High Performance Liquid Chromatography (HPLC). Results indicated significant (p ≤ 0.05) variation in both essential and non-essential amino acid content across locations. Among the essential amino acids, the accession from Abia had the highest arginine and lysine content; Rivers had the highest concentration of histidine and valine, while Enugu showed the highest methionine and threonine content, though statistically similar with that of Abia. Boiling significantly (p < 0.05) increased the amount of tryptophan, but all the other essential amino acids did not respond significantly to boiling. Among the non-essential amino acids, alaninie, asparagine, glutamine, glutamic acid and glycine responded significantly to location. Boiling reduced the quantities of cysteine and glutamic acid; but increased those of glutamine and lysine. Among the essential amino acids, only histidine and lysine were significantly (p < 0.05) influenced by interaction effects of location and processing such that boiling drastically reduced the levels of histidine in the seeds from Anambra and Rivers but enhanced the level of histidine in the seeds from Abia. Boiling also increased the amount of lysine in the Anambra seeds but reduced the lysine level in all the other accessions. In the case of the non-essential amino acids, asparagine, glutamine and glutamic acid responded significantly (p < 0.05) to interactive effect of the two factors. Principal Component Analysis (PCA) explained close to 50% of the total variability in amino acid composition, identifying arginine, asparagine, lysine, methionine, valine, glutamic acid, leucine, cysteine, threonine, alanine and isoleucine as the key amino acids for describing African walnut seeds in the south-eastern zone of Nigeria. It was clear from the study that seeds of this under-utilized forest species have full complement of the amino acids in sufficient amounts to meet the amino acid requirements of its teeming consumers. Keywords : African walnut, Plukenetia conophorum, amino acids, south-eastern Nigeria.

Vegetative propagation of African walnut (&lt;i&gt;Plukenetia conophora&lt;/i&gt;) using pre-treated stem cuttings of varied physiological ages

The effect of physiological age of stem cuttings and pre-planting treatment on adventitious root and shoot growth of stem cuttings of African walnut (Plukenetia conophora) were investigated at Nsukka, Nigeria in 2012. Nodal cuttings of semi-hardwood and softwood categories were dipped in water and coconut water for 30 minutes before planting. Cuttings used as control treatment were neither dipped in water nor coconut water. Factorial combinations of age of stem cutting and pre-planting treatment were arranged in completely randomized design (CRD) and replicated three times. Results of analysis of variance (ANOVA) indicated a non-significant main effect of age of stem cutting and pre-planting treatment on number of days to breaking of dormancy and shoot formation. Physiological age of cuttings significantly (p &lt; 0.05) influenced number of shoots formed, length of vine and number of leaves in favour of the semi-hardwood cuttings. Significant interaction between age of cuttings and pre-planting treatment was observed on percentage of cuttings with shoot and number of shoots per cutting. While semi-hardwood cuttings gave higher number of shoot when dipped in water, softwood cuttings (at 2- 4WAP) did better when dipped in coconut water. Available data suggest that softwood cuttings of this species are more amenable to clonal propagation. However, if semi-hardwood cuttings must be used, then dipping in water becomes a necessity. Evidences from this study affirm the practicability of clonal propagation of P. conophora via stem cuttings.Key words: African walnut, Pre-treatment, Vegetative propagation, Stem cuttings.

Physical properties of seeds of African walnut (&lt;i&gt;Plukenetia conophorum&lt;/i&gt; Muell Arg.) From South eastern Nigeria, and the effect of boiling on the proximate qualities

A study of the physical and proximate traits of seeds of African walnut (Plukenetia conophorum) from four locations (states) in south-eastern Nigeria was carried out in 2011. The locations considered were Enugu, Anambra, Abia and Rivers. Results of statistical analysis showed remarkable variation (p < 0.05) in all the seed physical traits across the sampled locations. Accessions from Anambra were outstanding in seed weight, seed circumference and seed diameter. However, the Enugu accession was the best in terms of seed edible proportion, followed by that of Abia, while seeds obtained from Anambra had the least percentage edible proportion. The accession from Rivers had the least seed weight, kernel weight, seed circumference and seed radius. Correlation coefficients among the physical traits indicated that seed weight had significant statistical linkage with all the other physical traits except seed coat thickness. Seed coat thickness, just like the seed edible proportion had poor statistical linkage with most of the seed physical traits; whereas kernel weight recorded a high significant positive relationship (r = 0.913**) with seed weight. Kernel weight, seed volume, seed circumference and seed diameter showed more or less similar pattern of relationship. Principal Components Analysis (PCA) results identified five physical traits including seed weight, kernel weight, seed volume, seed circumference and seed diameter as the most discriminatory traits among the accessions. Location significantly (p < 0.05) influenced only moisture, fat and ash content of the seeds. Fat concentration of the Anambra and Abia accessions were higher than those of the other two accessions. Boiling lowered the moisture content of seeds and significantly (p < 0.05) increased the fibre content. Location × processing interaction had no remarkable effect on the proximate attributes of the seeds. Correlation analysis linked high fat content with large kernel diameter. Thus, seeds with large kernels could be selected for fat content and those with small size could give higher percentage edible proportion. Seeds of African walnut in the sampled zone have adequate nutritional content to qualify as a protein-rich oilseed and have shown enough variability to warrant selection for further improvement. Keywords : Physical and proximate traits, African walnut, boiling treatment, southeast Nigeria.

Dietary effects of African walnut (Tetracarpidium conophorum) on the reproductive indices in male African catfish (Clarias gariepinus) broodstock

Dietary effects of African walnut (Tetracarpidium conophorum) on the reproductive indices in male African catfish (Clarias gariepinus) broodstock

Stock density and fruit yield of African walnut, Plukenetia conophora Mull-Arg (Syn. Tetracarpidium conophorum) in tropical lowland rainforests of southwest Nigeria

Despite the huge socio-economic potentials of the African walnut, Plukenetia conophora Mull-Arg, there is a dearth of information on stock density and yield studies under different site conditions. Therefore, this study was carried out to investigate the stock density and fruit yields of P. conophora in three different habitats (i.e. less disturbed natural forest, recently disturbed natural forest and plantation forest) within Omo Forest Reserve (OFR) and Shasha Forest Reserve (SFR) of Nigeria. Stratified random sampling technique was used to carry out inventory survey. Fruit yields were determined by collecting fruit falls through double sampling approach. Both descriptive and inferential statistics were used in analyzing the data at P = 0.05. Stock densities of P. conophora were 5.33+1.7stands/ha, 14.67+2.05stands/ha and 16.00+2.94stands/ha in OFR, while they were 7.33+0.47stands/ha, 14.67+1.25stands/ha and 10.67+04.7stands/ha in SFR for recently disturbed forest, less disturbed forest and plantation forest respectively. There were significant differences in number and distribution of species by forest types, but not between forest reserves. The mean yield of P. conophora/ha/yr was estimated at 7,800.00kg for OFR and 6,534.00kg for SFR. Yields from plantation area contributed more in OFR, while yields from less disturbed natural forest area were higher in SFR. Yields from recently disturbed natural forest were consistently lower in the two reserves. These results show that P. conophora thrives better in plantation and old re-growth forests. This information is pertinent towards improving the management of the species, increase its productivity and enhance benefits in a more sustainable manner to the rural populace.

Effect of Thermal Processing on the Nutritional, Antinutritional, and Antioxidant Properties of Tetracarpidium conophorum (African Walnut)

The effect of thermal processing (roasting and boiling) on the nutritional, antinutritional, and antioxidant properties of African walnut was studied. Tetracarpidium conophorum (African walnut) was subjected to thermal treatment of roasting (RWIS), boiling with shell (BWIS), and boiling without shell (BWOS). The resulting samples with raw nut (RAAW) which served as control were analysed for proximate composition, antinutritional components, and antioxidant activity. The protein, fat, and ash contents of the samples on dry basis were 29.14%, 54.14%, and 3.32% (RAAW); 24.13%, 61.75%, and 2.77% (BWIS); 22.47%, 62.65%, and 2.16% (BWOS); and 24.25%, 60.52%, and 2.48% (RWIS), respectively. Thermal processing had significant effect on all the proximate principles; boiling and roasting generally reduced the protein and ash contents of the nut. Boiling with or without shell reduced the phytate and tannin contents of the nut while roasting increased the level of these two antinutritional components; walnut boiled without shell however, had the lowest phytate and tannin contents of 0.815 mg/100 g and 0.239 mg/100 g, respectively. The antioxidant activities of the samples were 8.47% (RAAW), 13.82% (BWIS), 14.96% (BWOS), and 7.29% (RWIS). This study reveals that thermal processing has a significant effect on the proximate principles, bioavailability, and antioxidant activity of African walnut.

Impact of postharvest processing on the fungal population contaminating African walnut shells (Tetracarpidium conophorum Mull. Arg) at different maturity stages and potential mycotoxigenic implications

African walnut (Tetracarpidium conophorum Mull. Arg) is commonly processed by boiling or toasting and consumed as a snack or used as a thickener in many West African soup preparations. The nuts are usually exposed to both high temperatures and high relative humidity in open markets which predisposes them to fungal growth. Hence, the dangers of spore inhalation and resultant mycosis cannot be over-emphasized as retailers and consumers are always in direct contact with these nuts during harvest, processing and consumption. So far, there is no reported research on potential mycotoxin contamination of African walnut and whether this risk might be accentuated by processing. African walnut, at early and late maturity stages, were processed by toasting, boiling or left unprocessed before being stored at 25°C and 37°C, respectively under controlled relative humidity for 7days. Nuts were cracked and shell pieces cultured in malt extract agar (MEA) and Dichloran Glycerol 18 (DG18) media and incubated at 25°C for 7days. Results revealed that potential mycotoxigenic species – Aspergillus section Nigri, Aspergillus flavus/parasiticus, Fusarium spp. and Penicillium spp. – were frequently isolated. When compared with unprocessed nuts, toasting completely prevented fungal contamination in shell pieces from nuts in the non-stored (NSN) group at the early maturity stage, while boiling significantly reduced the level of contamination to about 58% (p<0.05). In general, simulating open market conditions caused 100% fungal contamination in all boiled samples and toasted samples at early maturity. However, contamination in toasted samples at late maturity was increased to 90 and 70% at 25°C in DG18 and MEA, respectively, while at 37°C contamination was 40 and 60% in DG18 and MEA, respectively. Mycotoxin analysis using Yeast Extract Sucrose (YES) agar and High Performance Liquid Chromatography (HPLC)–Fluorescence detection (FLD) showed that Aflatoxins — G1 (AFG1), B1 (AFB1), G2 (AFG2), and B2 (AFB2) were produced by 20 isolates with both AFG1 and AFB1 being predominant at concentration ranges 4.33–32,200 and 4.20–22,700ng/g plug weight, respectively. No ochratoxin A (OTA) was detected out of 23 isolates analysed. From these findings, it is suggested that toasting of nuts, preferably at early maturity is a safer processing option than boiling in terms of prevention of possible fungal growth on nut shells and risk of mycotoxin contamination.

Anti-ulcer activity of African walnut Tetracarpidium conophorum nuts against gastric ulcers in rats

ObjectiveTo determine the anti-ulcer activity of methanol extract of Tetracarpidium conophorum (Mull. Arg.) (METC) nuts in albino Wistar rats. MethodsMETC was investigated in pylorus ligation and ethanol induced models in experimental animals. Parameters such as gastric volume, pH, total and free acidity, and ulcer index were used as indicator for antiulcerogenic activity in both models. METC at doses of 250 and 500 mg/kg orally was used to determine whether the extract could produce significant protection of the gastric lesions by pylorus ligation and ethanol. ResultsThe extract at dose levels of 250 and 500 mg/kg exhibited significant (P<0.05) decrease in the gastric volume, total and free acidity while the pH of gastric juice was significantly (P<0.05) increased in both models. ConclusionsThe result showed that METC possesses anti-ulcer as well as cytoprotective properties which could be attributed to the presence of secondary metabolites.

Antioxidant activity and total phenolic content of some nuts commonly consumed in South-Western Nigeria

Improved health associated with frequent eating of nuts as one of the most unexpected nutritional discovery of the 1990s formed the basis of this study. Hence, the evaluation of some selected nuts commonly consumed as snacks in the South West of Nigeria for antioxidant activity (AA) and total phenolic content (TPC) using ferric-ion reducing antioxidant potential (FRAP) assay and Folin-Coicalteau method. Results show that AA of nuts such as kola nuts (Cola acuminata; Cola nitida), coconut (Cocos nucifera), bitter kola (Garcina cola), African walnut (Plukenetia conophora), and cashew nut (Anacardium occidentale) ranged from 13.0 to 53.21 µmol Trolox Equivalent/100 g dry weight while the total phenolic content ranged from 204.95 to 1955.14 mg Gallic acid Equivalent/100 g of dry sample. Statistical analysis of the relationship between AA and TPC showed a random, nonlinear relationship between the two parameters, suggesting that the antioxidant activity of the nuts is not dependent on phenolics. The result also indicates that the nuts can be utilized as scavenger/mopping agents of free radicals, which are usually generated by essential metabolic processes in the body and environmental pollutions; thereby alleviating the symptoms of chronic and degenerative diseases such as cancer, diabetes, hypertension and any other age-related diseases reported to be on the increase in developing countries.

Sperm Quality and Hormone Profile of Male Albino Rats FED with Seeds of African Walnut (Tetracarpidium conophorum, Mull)

Herbal plants have been found to be effective in traditional medicine for healthcare. However, the full potentials of these natural resources are yet to be fully explored. This research was coined at investigating the effects of Tetracarpidium conophorumseeds on the hormone and sperm profile of male albino rats. Forty eight albino rats of about twelve weeks weighing between 130-180g each were divided intofour groups (A, B, C and D) with twelve rats in each group. The test extract was obtained from the seeds and incorporated into the feed of the rats. Group A served as the control (without test substance) while groups B, C and D were fed with of 4, 8 and 1 2g/kg body weight (BW) of the test substance for the period of 63 days .Respectivelytheresults obtained from hormonal analysis show that there are significant difference (p 0.05). Results of semen quality show that there are significant differences (p 0.05). The results indicate that the seeds of

Essais de propagation par semis et marcottage aérien de Coula edulis Baill. et perspectives pour sa domestication

Le noisetier d'Afrique, Coula edulis Baill. Olacaceae, est un arbre des forêts denses humides africaines. Il produit des graines d'une grande valeur nutritive qui sont régulièrement récoltées et commercialisées par les populations d'Afrique centrale et de l'Ouest. Cependant, le manque d'informations relatives aux techniques de multiplication de l'espèce est la principale contrainte à sa domestication et à son intégration dans les systèmes agroforestiers locaux. L'étude, conduite parallèlement en pépinière et en milieu naturel, vise à mieux caractériser la germination de C. edulis et à déterminer ses aptitudes au marcottage aérien. Les résultats obtenus indiquent que la germination de C. edulis est très lente et échelonnée avec des taux de levée très faibles, voire nuls. De plus, les prétraitements appliqués aux graines se sont révélés inefficaces pour améliorer la vitesse et le taux de levée des semences. En revanche, le marcottage aérien permet de produire des plants de C. edulis d'une vigueur bien supérieure et dans un délai plus court que les semis en pépinière. Les résultats préliminaires du marcottage aérien sont prometteurs et ouvrent des perspectives intéressantes pour la multiplication et la domestication de l'espèce. L'intégration de Coula edulis dans les systèmes agroforestiers des plants issus du marcottage aérien est donc envisageable.

The effect of Tetracarpidium conophorum Mull. Arg. Hutch. &amp; Dalziel (Euphorbiaceae) seed extracts on testicular function in male albino rats

The effects of extracts of Tetracarpidium conophorum Mull. Arg. Hutch and Dalziel (Euphorbiaceae) or African walnut seeds were investigated on testicular function in male albino rats. Four different groups of animals (A – D) were administered with daily oral doses (200 mg/kg body weight) of extracts of n-hexane, chloroform, methanol and water respectively for 21 days. The control group (E) received equivalent volumes of normal saline. The animals were sacrificed after the 14th and 21st days of treatment. Testicular function was determined by serum testosterone levels by ELISA method, testicular weight, semen analysis (1, 2) and histological examination of the testes by H and E stain using Bouins fixative. Results indicated that n-hexane extract caused a significant increase in testosterone levels (p < 0.05) in a time dependent manner, while the methanol and water extracts caused decreases but no change in the chloroform extract-treated group. The body and testicular weights were increased above control values (p < 0.05). The superiority of the semen profile was in the order of groups treated with n-hexane>chloroform>water>methanol. Histological examination showed profound increases in spermatogenesis in the n-hexane treated group, while the methanol treated group showed deceases when compared with the control. This study therefore indicated that the n-hexane fraction of T. conophorum seeds probably has the ability to increase fertility in male rats and thus lends credence to the ethnobotanical claims in South Eastern Nigeria that ingestion of the seeds boosts male fertility and sexual performance.

Dispersal and predation of diaspores of Coula edulis Baill. in an evergreen forest of Gabon

AbstractThe African walnut (Coula edulis) is a tree species of African evergreen forests, the seeds of which are collected and traded by African people. Many animal species consume African walnut diaspores; however, their roles as dispersers or predators have yet to be clarified. In this study, we present observations conducted in two different habitats of a Gabonese region over a 3‐year period. The originality of this research resides in the combination of three complementary approaches: (i) the use of camera‐traps (ii) the exploration of land rodent burrows and (iii) the examination of elephant dung. In total, 408 camera‐trap photographs have shown seven animal species involved in the dispersal/predation of C. edulis. Among these seven frugivorous species, the bush pig was found to be the main consumer and predator of seeds. Land rodents (Muridae) are potential predators, as they damaged the seeds and buried them deep in the soil. They may also play a role in the regeneration process as a result of the loss of seeds during transportation. Finally, no seeds appeared to emerge intact from elephant faeces. These results indicate that the natural regeneration rate of this tree species is low, unless other complex mechanisms are involved.

Population distribution and threats to sustainable management of selected non-timber forest products in tropical lowland rainforests of south western Nigeria

Uncontrolled harvesting of non-timber forest products (NTFPs) poses a serious risk of extermination to several of these species in Nigeria. Yet, there is a paucity of information on the distribution, population status and sustainable management of NTFPs in most of the tropical lowland rainforests. We, therefore, assessed the population, distribution and threats to sustainable management of NTFPs within the tropical lowland rainforests of Omo and Shasha Forest Reserves, south western Nigeria. Data were obtained through inventory surveys on five top priority species including: bush mango (Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill), African walnut (Tetracarpidium conophorum (Mull. Arg.) Hutch. & Dalziel syn. Plukenetia conophora), chew-stick (Massularia acuminata (G. Don) Bullock), fever bark (Annickia chlorantha Setten & P.J.Maas syn. Enantia chloranta) and bush pepper (Piper guineense Schumach. & Thonn.). Purposive and stratified random sampling techniques were used for the inventory. Each forest reserve was stratified into three, viz: less disturbed natural forest (for areas that have been rested for at least ten years), recently disturbed natural forest (for areas that have suffered one form of human perturbation or the other in the last five years), and plantation forest (for areas carrying forest plantation). Data were collected from eighteen 10 m × 500 m belt transects located in the above strata. The species were generally fewer in both plantation and recently disturbed natural forest than the less disturbed natural forest, suggesting that forest disturbances (habitat modification) for other uses may have an effect on the occurrence and densities of the NTFPs. Exceptions to this trend were found for P. guineense and T. conophorum, which were fairly common in both plantation and recently disturbed natural forest. Among three tree NTFP species (i.e. I. gabonensis, M. acuminata and A. chlorantha), only I. gabonensis showed a significant difference in overall DBH size classes for both reserves (t=−2.404; df =21; p=0.026). Three tree NTFP species in both reserves further showed differences from the regular patterns of distribution of trees. The fairly regular reverse J-shaped size class distribution observed for M. acuminata in the study sites, however, suggests a recuperating population. In general, destructive harvesting of species, logging operations, low population size, narrow distribution ranges and habitat degradation are the major threats to the population of NTFPs in the study area. The implications of our findings for sustainable management of NTFPs in the study area are discussed and recommendations are made for a feasible approach towards enhancing the status of the species.