Kakamega Forest Research Articles

Effect of Participation in Commercial Production of Medicinal Plants through Community-Based Conservation Groups on Farm Income at Kakamega Forest, Kenya

ABSTRACT Forest conservation by peripheral communities is one of the most advocated strategies for ensuring sustainable supply of forest goods and services. In Kenya, although conservation activities generate considerable environmental improvements, studies evaluating the economic benefits are very limited. This study aimed at assessing the impact of participating in the commercialization training program by forest adjacent communities on farm income. Utilizing matching techniques, the analysis is based on the data collected from a randomly selected sample of farm households around Kakamega forest in Kenya. The results show that age, forest distance, forest benefit, market distance, and farming experience are the main factors that influence the participation in the commercialization program. Also, participating in commercial production of medicinal plants has a positive and significant effect on farmers’ income. The average treatment effect on the treated (ATT), based on three estimation algorithms, ranges from KSH. 80,047 to KSH. 176,788 per hectare, per year, implying that policy efforts that focus on the participation in the commercialization program of medicinal plants can enhance incomes among farm-dependent households. The findings from this study suggest that upscaling the participation in the commercialization program to other areas.

Effects of habitat fragmentation on the bats of Kakamega Forest, western Kenya

AbstractHabitat loss and fragmentation are major threats to biodiversity worldwide, and little is known about their effects on bats in Africa. We investigated effects of forest fragmentation on bat assemblages at Kakamega Forest, western Kenya, examining captures at edge and interior locations in three forest fragments (Buyangu, 3950 ha; Kisere, 400 ha; and Malava, 100 ha) varying in forest area and human-use regimes. Basal area, canopy cover, tree density and intensity of human use were used as predictors of bat abundance and species richness. A total of 3456 mist-net hours and 3168 harp-trap hours resulted in the capture of 4983 bats representing 26 species, eight families and four foraging ensembles (frugivores, forest-interior insectivores, forest-edge insectivores and open-space insectivores). Frugivores were frequently captured at the edges of the larger, better-protected forests, but also in the interior of the smaller, more open fragment. Forest-interior insectivores and narrow-space foragers predominated in the interiors of larger fragments but avoided the smallest one. Forest specialists showed positive associations with forest variables (canopy cover, basal area and tree density), whereas frugivores responded positively to the human-use indicators. On these bases, specialist species appear to be especially vulnerable to forest fragmentation.

Nest Architecture as a Tool for Species Discrimination of Hypotrigona Species (Hymenoptera: Apidae: Meliponini)

Hypotrigona species are difficult to identify morphologically. Here, we show that nest sites and nest architecture can be used to discriminate three Hypotrigona species found in Kenya. Hypotrigona gribodoi, H. araujoi and H. ruspolii colonies from Kakamega forest and H. gribodoi from Mwingi, were collected and placed in a meliponiary at the International Centre of Insect Physiology and Ecology (ICIPE). The following parameters were recorded: nest sites, internal nest entrances, external nest entrance colour and size, sizes (in terms of volume) of brood cells, honey and pollen pots, arrangement of brood cells and presence or absence of involucrum (cerumen covering brood). It was found that nest sites are specific to species. Hypotrigona gribodoi nests mostly in crevices in mud walls while H. ruspolii and H. araujoi nest in cavities in specific tree species, mainly in indigenous forests. The colour of external nest entrances varies between the species. H. araujoi’s is yellowish brown, H. gribodoi’s is white or cream while that of H. ruspolii is dark brown. There is an internal nest entrance in H. gribodoi, which is absent in the other two Hypotrigona species. Brood cells are clustered in H. gribodoi and H. ruspolii whereas H. araujo's form vertical semi comb-like layers. The area of the apical opening of the entrance tube and volumes of brood cells, honey and pollen pots differ significantly between the three Hypotrigona species. Therefore, nest sites and nest architecture can be used to discriminate three Hypotrigona species. Furthermore, the study indicates that conservation of indigenous forests, the main habitat for H. araujoi and H. ruspolii is important for their conservation.

Further information on Lolibaia Gorbunov Gurko, 2017 (Lepidoptera: Sesiidae: Synanthedonini) with description of three new species from tropical Africa.

The knowledge of the clearwing moth genus Lolibaia Gorbunov Gurko, 2017, recently described from South Sudan and until now known only from a single, damaged specimen, is extended by three new species from different parts of Africa including the as yet unknown female of the genus. L. jurateae sp. nov. is based on a single male from Kakamega Forest, Kenya; L. triangularis sp. nov. is based on six males from different localities in north-western Zambia, and L. polythyris sp. nov. is described from two females from the Eastern Cape and KwaZulu-Natal Provinces, South Africa.

Determination of Antimicrobial Activity of Extracts of Indigenous Wild Mushrooms against Pathogenic Organisms.

Objective This study has investigated the antimicrobial activity of extracts of indigenous wild mushrooms against selected organisms. Methods Thirty-five (35) indigenous wild mushrooms were collected from Arabuko-Sokoke and Kakamega National Reserve Forests, Kenya. All mushrooms were identified and their contents were extracted and screened for their antimicrobial activities against Escherichia coli (clinical isolate), Klebsiella pneumoniae (ATCC 13883), Pseudomonas aeruginosa (clinical isolate), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), MRSA (ATCC 33591), Candida albicans (clinical isolate), and Candida parapsilosis (ATCC 90018) using tetrazolium microtiter plate bioassay method. Results Of the 35 tested mushroom extracts, extracts of three (3) mushrooms, namely, Trametes spp. (Arabuko-Sokoke forest), Trametes, and Microporus spp. (Kakamega forest), have shown promising antimicrobial activities against the tested organisms. The S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), and Methicillin-Resistant Staphylococcus aureus (MRSA) (ATCC 33591) were the most susceptible to chloroform extract of Trametes spp. collected from Arabuko-Sokoke forest. Of the tested organisms, S. aureus (ATCC 25923) was the most susceptible whereas E. coli was the most resistant organism to the hot water extract of Trametes spp. collected from Arabuko-Sokoke forest. Chloroform extract of Microporus spp. has shown the highest antibacterial activity against S. aureus (ATCC 25923), MRSA (ATCC 33591), and K. pneumoniae (ATCC 13883) but limited activity against E.coli. All extracts of the three wild mushrooms have shown the most antibacterial activities against S. aureus (ATCC 25923). Conclusion The present study has shown that the extracts of the three wild mushrooms have shown promising antimicrobial activities against the tested organisms.

Population Status, Distribution Patterns and Conservation Needs of Endangered <i>Croton alienus</i> Pax in Kenya

Kenya has a very rich plant biodiversity, many which are economically important. However this rich botanical resource continue to decline at an alarming rate as a result of over-exploitation through unsustainable human activities and unpredictable effect of changing climate. Endemic species with restricted geographic ranges and specific habitats are most vulnerable to extinction under the changing environmental and climatical conditions. To aid in their conservation, sound knowledge on their population status, distribution and conservation is urgently needed. The population status, distribution pattern, economic uses and conservation needs of Croton alienus Pax 1909, an endemic and endangered plant species in Kenya are reviewed. This was achieved through screening of herbarium specimen at East Africa Herbarium and detailed review of published and un-published research articles. The result indicates, Croton alienus has restricted area of occupancy occurring mainly in high altitude region between 1500-1800 m above sea level. Due to its narrow altitude range, Croton alienus is restricted to forests in central Kenya (Aberdare forest, Mt Kenya forest), Nairobi region (Karura forest, Ngong forest, Arboretum) and Western Kenya (Kakamega forest). Very low population density of 1 species per hectare in Karura forest suggests urgent conservations needs. Earlier conservations efforts included seed propagation activities to produce seedling, but their sustainability may have been halted by its limited usage. The species is medicinal with antibiotic properties against Croton alienus and Leishmania donovanii micro-organisms which can be tapped to aid its domestication and conservation. This review highlights need for urgent conservation measures for endemic species with restricted geographic ranges and specific habitat needs like Croton alienus in awake of climate change.

On-Farm Tree Abundance and Biomass Carbon Stocks of <i>Grevillea robusta</i> and <i>Eucalyptus saligna</i> on Farms Around Kakamega Forest

The integration of trees on farmlands has recently received attention due to their contribution to livelihoods improvement and climate change mitigation. They provide ecosystem services (ESs) like climate change mitigation, improvement of soil fertility, provision of timber and fuelwood among others. The choice of trees to plant depends on the role the farmer intends to put them into and the size of the farm. The trees can either be indigenous or exotic andare mostly planted along farm boundaries, in home gardens, as woodlots orientation among others. This study was conducted in western part of Kenya on farmlands that mostly border the Kakamega Forest. The study soughtto determine abundance, distribution and biomass carbon stocks of <i>Grevillea robusta</i> and <i>Eucalyptus saligna</i> for enhanced climate change mitigation. A total of (N=3,468) trees were inventoried in 80 farms with a total of 27.5ha. The average size of farms where the survey was done was about 1.28±1.01 ha. <i>Eucalyptus saligna</i> had a tree abundance 1133 (33%) of the total trees sampled while <i>Grevillea robusta</i> had 2,335 (67%). Two sites were purposively selected (Lubao and Tea zone area). In the Lubao site, <i>Eucalyptus saligna</i> abundance was 627 (29%) while <i>Grevillea robusta</i> abundance was 1565 (71%) of the total trees sampled. In Tea Zone site, <i>Eucalyptus saligna</i> abundance was 506 (40%) while <i>Grevillea robusta</i> tree abundance was 770 (60%). Total biomass estimated in the study area was 3.86±0.21Mgha^-1(1.96Mg C ha^-1). This was distributed as aboveground biomass (2.8±0.12Mgha^-1) and belowground biomass (0.87±0.41Mgha^-1). There was no significant difference in biomass among farms in Lubao (F=43.12; p=0.34) and in Tea zone sites (F=53.12; p=0.23). Lubao site had an estimated biomass of 1.97±0.023Mgha^-1 distributed as above ground biomass (1.31±0.043Mgha^-1) and below ground biomass (0.67±0.023Mgha^-1). Tea zone site had an estimated biomass of 1.99±0.38Mgha^-1. This was distributed as above ground biomass (1.58±0.023Mgha^-1) and below ground biomass (0.40±0.18Mgha^-1). Biomass was significantly different among the agroforestry practices in Lubao (F=13.1; p=0.002) and in Tea Zone (F=29.12; p=0.001). Hedgerow had the highest biomass among the agroforestry practices in Lubao (1.91±0.16Mgha^-1) and in Tea zone sites (1.7±0.23Mgha^-1). Alley cropping that was only practiced in Lubao had the least biomass (0.0044±0.009Mgha^-1). The twotree species provided benefits for household use and at the same time for monetarysale. Firewood and timber were the most mentioned (n=80). This was followed by construction material and fencing material. These functions/uses were most preferred by the <i>Eucalyptus grandis</i>.

Distance Effects on Diversity and Abundance of the Flower Visitors ofOcimum kilimandscharicumin the Kakamega Forest Ecosystem

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ ofOcimum kilimandscharicumin Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates thatOcimum kilimandscharicumflower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.

Does Wood Fuel Gathering for Household Use Follow an Optimality Model? A Study from Kakamega Forest, Western Kenya

Successful management of forests, especially in the context of subsistence wood fuel use, can be improved by the application of theoretic models that predict patterns of use. A first step in this approach is understanding the decision rules of people using forests. While optimal foraging theory is normally applied to foraging for food, it also makes sense to apply it in the context of “foraging” for wood fuel. In this study, we applied a time allocation model of optimal foraging theory to wood gathering decisions in communities around Kakamega Forest, a mid-altitude seasonal tropical rain forest. The model predicts that the amount of wood gathered should increase with the distance to the wood source. We found that the predictions of OFT are supported, but only for adults and more strongly on a weekly scale. Based upon the results, we then discuss future improvements of the model to better understand and predict human use.

English

Infectious diseases remain a global health burden due to development of antibiotic resistance by pathogenic microorganisms. Antibiotic resistance has led to increased number of deaths among children and adults. This study sought to isolate and identify fungal endophytes from selected Kenyan medicinal plants and screen them and their extracts for bioactivity against selected test human pathogens. Fifty-five fungal endophytes were successfully isolated from fresh leaves of twenty-three medicinal plants from Kakamega forest. The DNA of fungal endophytes was extracted and molecular characterization was done through sequencing of the internal transcribed spacer region (ITS). The isolated fungal endophytes belonged to nine genera in the Ascomycota group, namely Fusarium, Colletotrichum, Trichothecium, Phomopsis, Pestalotiopsis, Cladosporium, Aspergillus, Phoma, and Chaetomium. Extracts from Aspergillus sp. demonstrated antimicrobial activity at low concentrations of 2.34 µg/ml against B. subtilis and 9.38 µg/ml against Candida tenius; while extracts from Colletotrichum sp. demonstrated antimicrobial activity at moderate concentration (37.5 µg/ml) against B. subtilis in the serial dilution assay. These results show that medicinal plants are a reservoir to a diversity of fungal endophytes that could be exploited as sources of natural products of pharmaceutical importance. Key words: Antibiotic resistance, antimicrobial, bioactive, fungal endophytes.

Microporenic Acids A-G, Biofilm Inhibitors, and Antimicrobial Agents from the Basidiomycete Microporus Species.

The need for effective compounds to combat antimicrobial resistance and biofilms which play important roles in human infections continues to pose a major health challenge. Seven previously undescribed acyclic diterpenes linked to isocitric acid by an ether linkage, microporenic acids A-G (1-7), were isolated from the cultures of a hitherto undescribed species of the genus Microporus (Polyporales, Basidiomycota) originating from Kenya's Kakamega forest. Microporenic acids D and E (4 and 5) showed antimicrobial activity against a panel of Gram positive bacteria and a yeast, Candida tenuis. Moreover, microporenic acids A and B (1 and 2) demonstrated dose-dependent inhibition of biofilm formation by Staphylococcus aureus. Compound 1 further showed significant activity against Candida albicans and Staphylococcus aureus preformed biofilms.

Dietary Variability in Redtail Monkeys (Cercopithecus ascanius schmidti) of Kibale National Park, Uganda: the Role of Time, Space, and Hybridization

Studies of the diet of different groups of the same species allow us to understand intraspecific dietary variability. I collected dietary data from six neighboring groups of redtail monkeys (Cercopithecus ascanius schmidti) and three hybrid monkeys over 12 years at Ngogo and from one group at Kanyawara in Kibale National Park, Uganda and compared these results with previous studies of redtail diets elsewhere in Kibale and from the Kakamega Forest of Kenya. I scored feeding as a particular monkey ingesting a species-specific plant part, or catching insects from a species-specific substrate. A new feeding score was tallied for the same combination of parameters only after a 30-min interval or if the identity of one of the three parameters changed. I counted trees along transects in the home ranges of the two main study groups to calculate food selection ratios. I used chi-square tests to compare diets between groups and time periods and Spearman rank correlation coefficient tests for dietary correlates. These comparisons reveal considerable variation in plant parts and species eaten by redtails between months, years, and neighboring groups with overlapping ranges. Selection ratios show that some tree species are important sources of plant food, while others are more important as sources of invertebrates. The high incidence of insectivory by redtails demonstrates another ecological role they play in addition to seed dispersal. The intrademic variation in diets I describe for Kibale was often as great as and sometimes greater than the interdemic variation. The diets of the hybrid monkeys at Ngogo differed in some ways from their parental species, particularly in their greater consumption of invertebrates. Introgression may have led to some of these differences within and between redtail demes. The pronounced variability in redtail diets demonstrates why a typological perspective of species is unwarranted and that the validity of interspecific comparisons requires a thorough understanding of intraspecific variation.

Identification of stingless bees (Hymenoptera: Apidae) in Kenya using morphometrics and DNA barcoding

Stingless bees are important pollinators of wild plants and crops. The identity of stingless bee species in Africa has not been fully documented. The present study explored the utility of morphometrics and DNA barcoding for identification of African stingless bee populations, and to further employ these tools to identify potential cryptic variation within species. Stingless bee samples were collected from three ecological zones, namely Kakamega Forest, Mwingi and Arabuko-Sokoke Forest, which are geographically distant and cover high, medium and low altitudes, respectively. Forewing and hind leg morphometric characters were measured to determine the extent of morphological variation between the populations. DNA barcodes were generated from the mitochondrial cytochrome c-oxidase I (COI) gene. Principal Component Analysis (PCA) on the morphometric measurements separated the bee samples into three clusters: (1) Meliponula bocandei; (2) Meliponula lendliana + Plebeina hildebrandti; (3) Dactylurina schmidti + Meliponula ferruginea black + Meliponula ferruginea reddish brown, but Canonical Variate Analysis (CVA) separated all the species except the two morphospecies (M. ferruginea reddish brown and black). The analysis of the COI sequences showed that DNA barcoding can be used to identify all the species studied and revealed remarkable genetic distance (7.3%) between the two M. ferruginea morphs. This is the first genetic evidence that M. ferruginea black and M. ferruginea reddish brown are separate species.

Quantifying the rate of subsistence wood harvesting from a tropical rainforest in Kenya

AbstractOne of the major threats to tropical forests throughout the world is the frequency and intensity with which local people use forests for subsistence. Kakamega Forest in Kenya is one such forest, in which fuelwood harvest is a primary use. The Kenya Forest Service and Kenya Wildlife Service have tried to regulate subsistence harvesting in this forest. However, high human population density (c. 542 people per km2) and extreme poverty leave local people little choice but to use forest resources to survive. We investigated patterns of wood use by people across Kakamega Forest. Our results indicate that wood harvesters prefer indigenous as opposed to non-indigenous wood, as the former sells for a premium price. Harungana madagascariensis and Psidium guajava were the most harvested indigenous and non-indigenous woods, respectively. Our data suggest that because market economies seem to drive forest use, perhaps they can be used to incentivize forest conservation. Proper integration of economic forest conservation interventions, economic diversification, and effective forest management are needed to protect Kakamega Forest.

Medicinal plants used for management of malaria among the Luhya community of Kakamega East sub-County, Kenya

BackgroundMalaria remains a major health problem worldwide especially in sub-Saharan Africa. In Kenya, 80% of the population is at risk of contracting the disease. Pregnant mothers and children under five years are the most affected by this disease. Antimalarial drug resistance poses a major threat in the fight against malaria necessitating continuous search for new antimalarial drugs. Due to inadequate and inaccessible health facilities, majority of people living in rural communities heavily depend on traditional medicine which involves the use of medicinal plants for the management of malaria. Most of these indigenous knowledge is undocumented and risks being lost yet such information could be useful in the search of new antimalarial agents. Aim of studyAn ethnobotanical survey was carried out among the Luhya community of Kakamega East sub-County, a malaria epidemic region, with the aim of documenting the plants used in the management of malaria. Materials and methodsSemi-structured questionnaires were used to collect information from 21 informants who included traditional medicine practitioners and other caregivers who had experience in use of plants in management of malaria. These were drawn from 4 villages located in Kakamega East sub-county, within Kakamega County based on their differences in topography. Information recorded included plant names, parts used, mode of preparation and administration and the sources of plant materials. A literature search was conducted using PubMed and google scholar to identify the reported traditional uses of these plants and studied antiplasmodial activities. ResultsIn this study, 57% of the informants were aged above 50 years and a total of 61% had either no formal education or had only attained primary school education. A total of 42 plant species belonging to 24 families were identified. Most plants used in the management of malaria in this community belonged to Lamiaceae (18%), Leguminosae (9%) and Compositae (9%) plant families. Plants mostly used included Melia azedarach L, Aloe spp, Ajuga integrifolia Buch. Ham, Vernonia amygdalina Del., Rotheca myricoides (Hochst.) Steane and Mabb, Fuerstia africana T.C.E.Fr., Zanthoxylum gilletii (De Wild.) P.G.Waterman and Leucas calostachys Oliv. Rumex steudelii Hochst.ex A. Rich and Phyllanthus sepialis Müll. Arg are reported for the first time in the management of malaria. Although Clerodendrum johnstonii Oliv. (Jeruto et al., 2011) and Physalis peruviana L.(Ramadan et al., 2015) are reported in other studies for management of malaria, no studies have been carried out to demonstrate their antiplasmodial activity.The plant parts mostly used were the leaves (36%) and stem barks (26%). Majority of these plants were prepared as decoctions by boiling and allowed to cool before administration (66%) while infusions accounted for 28% of the preparations. The literature mined supports the use of these plants for the management of malaria since most of them have demonstrated in-vitro and in-vivo antiplasmodial activities. ConclusionMost of the reported plant species in this study have been investigated for antiplasmodial activity and are in agreement with the ethnomedical use. Two (2) plants are reported for the first time in the management of malaria. There is need for documentation and preservation of the rich ethnomedical knowledge within this community given that most of the practitioners are advanced in age and less educated. There is also the danger of over-exploitation of plant species as most of them are obtained from the wild, mainly Kakamega forest. Therefore, there is need for determining the economically and medicinally important plants in this community and planning for their preservation.

Allellopathic potential of invasive Psidium guajava L., against selected native tree species in Kakamega Tropical Forest, Western Kenya.

Studies have previously attributed P. guajava invasiveness to its aggressive regeneration and profuse seeding. This study, however verified that its allellopathic influence on native plant species also plays an important role in its invasiveness. Extracts from green fresh and brown dry leaves were concentrated to 20%, 10% and 5% with distilled water used as control. Seeds from Markhamia lutea, Diospyros mespiliformis, Cordia africana and Croton megalocarpus; common native species in Kakamega forest, were treated with these extracts in a completely randomised design to determine the extracts impact on their germination, shoot and root elongation. Experiments were replicated 3 times. The two extracts significantly inhibited seed germination, shoot and root length elongation in C. megalocarpus and in C. africana, while in M. lutea and D. mespiliformis the differences were not significant. The study indicated that the inhibitory effect was concentration dependant and was more pronounced at a higher concentration. P. guajava has allellochemicals inherent in it which inhibits germination and growth of some natives species. Its invasion of the forest can be mitigated partly by planting resistant trees species like M. lutea and D. mespiliformis, which exhibited resistance to its allelopathic suppression.This study is significant as it will help reduce spread of P. guajava within Kakamega Forest, and can also be replicated in other similar forests in the world with problems of invasion.

Geological and geophysical characteristics of massive sulphide deposits: A case study of the Lirhanda massive sulphide deposit of Western Kenya

An integrated geophysical ground survey was conducted on an airborne electromagnetic (EM) anomaly located in Kakamega forest of Western Kenya. The purpose of the study was to establish the existence of massive sulphides and identify suitable optimal geophysical method(s) for the investigation of similar anomalies. The study was also expected to provide information on the geological and geophysical characteristics of the deposit.Field work involved electromagnetic methods: Vertical Loop (VLEM), Horizontal Loop (HLEM), TURAM EM and potential field methods: gravity and magnetics. Geochemical sampling was carried out concurrently with the geophysical survey.All the geophysical methods used yielded good responses. Several conductors conforming to the strike of the geology were identified. TURAM EM provided a higher resolution of the conductors compared to VLEM and HLEM. The conductors were found to be associated with positive gravity anomalies supporting the presence of bodies of higher density than the horst rock. Only the western section (west of 625W) of the grid is associated with strong magnetic anomalies. East of 625W strong EM and gravity anomalies persist but magnetic anomalies are weak. This may reflect variation in the mineral composition of the conductors from magnetic to non-magnetic. Geochemical data indicates strong copper anomalies (upto 300 ppm) over sections of the grid and relatively strong zinc (upto 200 ppm) and lead (upto 100 ppm) anomalies. There is a positive correlation between the location of the conductors as predicted by TURAM EM and the copper and zinc anomalies.A test drill hole proposed on the basis of the geophysical results of this study struck massive sulphides at a depth of 30m still within the weathered rock zone. Unfortunately, the drilling was stopped before the sulphides could be penetrated. The drill core revealed massive sulphide rich in pyrite and pyrrhotite.An attempt has been made to compare characteristics of the Lirhanda massive sulphide deposit with those of better documented massive sulphides. Despite the fact that very little is known about Lirhanda, there are several similarities on the characteristics compared. These include evidence of back arc regional environment, calc-alkaline volcanic associations, conformity of anomalies to the structural trend of the host rock, proximity of synvolcanic rift, dispersive anomalies of copper and zinc in soils, presence of gossan and association of the deposit with strong EM anomalies.

Determinants of aboveground carbon offset additionality in plantation forests in a moist tropical forest in western Kenya

Few studies have attempted to identify factors that contribute to aboveground carbon offset additionality in forest restoration planting in the tropics. Moreover, those that have compared aboveground carbon offset potential of naturally regenerating secondary forests and plantation forests have yielded conflicting results regarding the ability of the latter to attain carbon offset additionality, thus limiting broad adoption of carbon-driven forest restoration interventions. We assessed woody species diversity, stem density, stem diameter and wood specific gravity of secondary and plantation forests in Kakamega Forest in western Kenya to identify determinants of aboveground carbon offset additionality in plantation forests. Secondary forests comprised old-growth, middle-aged and young vegetation stands. Plantation forests consisted of mixed indigenous, Maesopsis eminii indigenous monoculture and Cupressus lusitanica, Pinus patula and Bischofia javanica exotic monoculture stands. Assessment was carried in 135 sample plots in three forest blocks using stratified systematic sampling in nested plots. Analysis of variance indicated that there was no significant difference in woody species diversity between secondary and plantation forests due to natural forest succession in both forest types. Mixed indigenous plantation had more aboveground carbon stock than secondary forest stands of comparable stand age due to its greater proportion of tree species with high wood specific gravity and large tree diameter. Old-growth secondary forest had more aboveground carbon stock than monoculture forest plantations due to its relatively higher wood specific gravity. Middle-aged secondary forest had relatively lower aboveground carbon stock than plantation forests of comparable stand age because of its smaller tree diameter. The results suggest that stem diameter and wood specific gravity are the most important determinants of aboveground carbon offset additionality. Thus, forest managers and investors in carbon offset projects can achieve aboveground carbon offset additionality in forest restoration interventions by planting tree species with relatively higher wood specific gravity and manipulating them to attain large stem diameter through silvicultural management.

Limits and paradoxes in the development of ecotourim in Kenya: implications on the sustainability of the natural environment

ABSTRACTEcotourism entails travel to natural and relatively undisturbed areas. The government plays a crucial role in delineation and management of such areas. In addition, the private sector sees to it that such areas exist for posterity. In Kenya, one such institution is Ecotourism Kenya (EK) whose motto is to ‘link communities, tourism and conservation’. First, this paper takes a critical look at the conservation agenda advanced by EK through the national eco-rating scheme launched in 2002 that seeks to give every tourist accommodation facility a chance to participate, learn and apply best practices of sustainable tourism. Moreover, the theme of community empowerment is discussed based on the accommodation facilities initiated by EK in Kakamega Forest Reserve (240 km2) in Western Kenya. This paper concludes that, while certification can be a beneficial tool if properly implemented, this is not the case given that there were only 100 establishments certified in Kenya under this scheme by the year 2012. In addition, ecotourism in Kenya needs to dialogue and clearly define its agenda in order to minimize contradictions and dilemmas inherent in ecotourism practice.

Molecular characterization of wood ear mushrooms [Auricularia sp.] from Kakamega Forest in Western Kenya

Molecular characterization of wood ear mushrooms [Auricularia sp.] from Kakamega Forest in Western Kenya