Elgon Forest Research Articles

Mapping deforestation and recovery of tropical montane forests of East Africa

Deforestation poses a major threat to the tropical montane forest ecosystems of East Africa. Montane forests provide key and unique ecological and socio-economic benefits to the local communities and host diverse flora and fauna. There is evidence of ongoing deforestation and forest clearance in these montane forests although estimates diverge among different sources suggesting rates of 0.4%–3% yr−1. Quantifying deforestation rates and forest disturbance is critical to design conservation and sustainable management policies for forest management. This study quantified the rate of deforestation and forest recovery over the last three decades for the Mau Forest Complex and Mount Elgon forests in Kenya and Uganda using Landsat time-series satellite imagery. With the analysis, classification accuracies of 86.2% and 90.5% (kappa 0.81 and 0.88) were achieved for the Mau Forest Complex and the Mt Elgon forests, respectively. 21.9% (88,493 ha) of the 404,660 ha of Mau forest was lost at an annual rate of −0.82% yr−1 over the period between 1986 and 2017. More positively, 18.6% (75,438 ha) of the forest cover that was disturbed during the same period and is currently undergoing recovery. In Mt Elgon forest, 12.5% (27,201 ha) of 217,268 ha of the forest cover was lost to deforestation at an annual rate of −1.03% yr−1 for the period between 1984–2017 and 27.2% (59,047 ha) of the forest cover disturbed is undergoing recovery. The analysis further demonstrated agriculture (both smallholder and commercial) was the main driver of forest cover loss in Mau forest, accounting for 81.5% (70,612 ha) of the deforestation, of which 13.2% was due to large scale and 68.3% was related to the smallholders. For the Mt Elgon forest, agriculture was also the main driver accounting for 63.2% (24,077 ha) of deforestation followed by the expansion of human settlements that contributed to 14.7% (5,597 ha) of forest loss. This study provides accurate and novel estimates of the rate of deforestation for the Mau forest complex and Mt Elgon forest ecosystems. These rates are higher than previously estimated and recent deforestation has been identified, which provides a quantitative basis for forest restoration programs and to design conservation policies.

Influence of Settlement Activities on Sustainable Households’ Livelihoods of the Inhabitants in Mount Elgon Forest, Bungoma County, Kenya

Mount Elgon Forest has declined primarily due to anthropogenic activities. The aim of this paper was to investigate the influence of settlement activities on sustainable household’s livelihoods of inhabitants in Mount Elgon Forest, Bungoma County, Kenya. This study used cross-sectional research design and mixed methodology. The target population was 12842 household heads, 4 ward administrators, 12 chiefs, 1 Kenya Forest service personnel and 1 NEMA official. A sample of 373 household heads, 4 ward administrators, 12 chiefs, 1 Kenya Forest Service Personnel and 1 NEMA official took part in the study. Questionnaires, interview guides and Focus Group Discussions were used to collect data. Validity was determined by consulting supervisors while reliability was ascertained through piloting and use of Cronbach Alpha Coefficient. Quantitative data was analysed using frequencies, percentages, means, Standard deviation and Pearson Correlation analysis. Qualitative data was thematically classified and arranged before being reported in narrations and quotations. Analyzed data was presented using tables and figures. The study found a significant positive correlation between settlement activities and sustainable households’ livelihoods (r = .614; p = .000). It was recommended that there was a need to devise ways of reducing population density and land fragmentation leading to reduced dependency on forest products. The findings of the study will be crucial to professional bodies and institutions such as Kenya Forest service, Kenya wildlife service and NEMA in relooking at the approaches that enhance livelihoods among forest users and thus come up with strategies for effective management of forests improving on sustainable livelihoods.

Understanding the nexus between forest dependence and willingness to pay for forest conservation: case of forest dependent households in Kenya

PurposeForests support human livelihoods and mitigate against climate change, yet they are at a risk of irreversible loss due to high degradation rates. The success of forest conservation mechanisms depends on involvement and support by forest dependent communities. In this paper, the authors assess forest dependent household's willingness to pay (WTP) labour or cash for a conservation programme seeking to restore degraded forestland in Mount Elgon Forest, Kenya.Design/methodology/approachData were collected from 919 households in Mt Elgon forest reserve, Kenya. A double bounded contingent valuation approach was used to examine households' WTP and an ordered probit model to estimate the determinants of WTP.FindingsThe findings of the study show a higher WTP for conservation through labour days (12 days/month, equivalent to 1800 KES/month) compared to cash (KES 450/month). Forest dependence has a significant influence on households' willingness to support conservation activities. A higher WTP was observed amongst households with higher vulnerability (high shocks value, low asset value and those in the poorest wealth categories) implying that they are more willing to contribute for forest conservation.Originality/valueWhile emerging literature on WTP for forest conservation is growing, few studies have paid attention on the influence of forest dependence on WTP for forest conservation. There are limited studies on use of in-kind contribution as a payment vehicle for WTP. The study's findings show a high WTP in form of labour suggesting the importance of embracing in-kind contribution as a mechanism of supporting forest conservation in contexts of developing countries.

Modelling cropland expansion and its drivers in Trans Nzoia County, Kenya

Population growth and increasing demand for agricultural production continue to drive global cropland expansions. These expansions lead to the overexploitation of fragile ecosystems, propagating land degradation, and the loss of natural diversity. This study aimed to identify the factors driving land use/land cover changes (LULCCs) and subsequent cropland expansion in Trans Nzoia County in Kenya. Landsat images were used to characterize the temporal LULCCs in 30 years and to derive cropland expansions using change detection. Logistic regression (LR), boosted regression trees (BRTs), and evidence belief functions (EBFs) were used to model the potential drivers of cropland expansion. The candidate variables included proximity and biophysical, climatic, and socioeconomic factors. The results showed that croplands replaced other natural land covers, expanding by 38% between 1990 and 2020. The expansion in croplands has been at the expense of forestland, wetland, and grassland losses, which declined in coverage by 33%, 71%, and 50%, respectively. All the models predicted elevation, proximity to rivers, and soil pH as the critical drivers of cropland expansion. Cropland expansions dominated areas bordering the Mt. Elgon forest and Cherangany hills ecosystems. The results further revealed that the logistic regression model achieved the highest accuracy, with an area under the curve (AUC) of 0.96. In contrast, EBF and the BRT models depicted AUC values of 0.86 and 0.77, respectively. The findings exemplify the relationships between different potential drivers of cropland expansion and contribute to developing appropriate strategies that balance food production and environmental conservation.

LAND USE CHANGES AND FLORAL DIVERSITY IN KENYA’S MT. ELGON FOREST ECOSYSTEM

<p><strong>Background</strong>. Montane forests encompass spectacular landscapes, a wide variety of ecosystems, a great diversity of species, and distinctive human communities. Mountain forests support about one quarter of world’s terrestrial biodiversity and include nearly half of the world’s biodiversity “hotspots.<strong> </strong>Understanding of land use change (LUC) in mountain forest ecosystem is crucial for sustainable management of the ecosystem especially in developing countries like Kenya where the majority of the people depend on natural resources for their livelihoods. Changes in land use in this forest ecosystem could lead to a decline in biodiversity and in the livelihoods of the forest adjacent communities. <strong>Objective:</strong> To evaluate the differences in land use changes and floral diversity of Mt. Elgon forest ecosystem. <strong>Methodology:</strong> Differences in land use changes on floral diversity were evaluated using quadrats that were placed in different land uses to measure species diversity and abundance. The Shannon-Weiner diversity index and Whittaker beta diversity index was used to determine changes and similarities in floral diversity, while Kruskal-Wallis test and chi square test was used to determine differences in species abundances. <strong>Result:</strong> This study established that there were differences in floral diversity in relations to land use changes. The Shannon-Weiner diversity index revealed that control (natural forest) site had the highest species diversity (H=2.07331, evenness=0.884), followed by indigenous plantations (H=1.93962; evenness 0.69957), urban settlements (H=1.85081; evenness=0.66754), Nyayo Tea Zone (H=1.5324, evenness=0.56), mixed farming (H=1.43694, evenness=0.43694) and exotic plantation (H=1.28231, evenness=0.61612). Whittaker beta diversity index for control site verses urban settlements was (0.5385), indigenous plantations (0.2222), Nyayo Tea Zone (0.1429) while mixed farming and exotic plantations (0.000). Kruskal-Wallis test revealed a statistically significant differences in total number of plant species in the various study sites (H=8.288; P=0.049). Similarly, the results revealed a significant difference between specific plant communities (trees, shrubs, herbs, ferns, and climbers) in the study area (H=38.116; P=0.000). Chi square test of homogeneity was used to test difference in distribution of species communities in different location and the results revealed that the differences were insignificant. <strong>Implications:</strong> Results of species diversity analyses show differences in floral diversity and similarities in areas under different land uses. <strong>Conclusion</strong>: There are significant differences in floral diversity in areas under different land uses of Mt. Elgon forest ecosystem. Species diversity and similarity of indigenous planted forests and urban settlement closely approach that of the natural forests. Floral diversity play a critical role in provisioning of essential ecosystem services.</p>

Understanding forest users' participation in participatory forest management (PFM): Insights from Mt. Elgon forest ecosystem, Kenya

Participation of local communities in forest management decision-making has been promoted as a mechanism of improving livelihoods and forest conditions, yet the level of participation in many programs remains low. Using data from a cross-sectional survey of 924 forest-dependent households in Western Kenya, we examine the factors that support or constrain forest dependent people's participation in a Participatory Forest Management (PFM) program. We run a probit model to assess households' choice to join PFM and then compute a Participation Index (PI) for forest users' participation across different stages of the PFM program – planning, implementation and Monitoring and Evaluation (M&E). The determinants of participation are then analyzed using the fractional regression approach. Results show that over half (52%) of the respondents participated in PFM. While vulnerability to shocks, being in a farmers' group, a household's access to the forest within the previous 12 months and access to extension were associated with the likelihood of participating in PFM, the influence of the household head's age and education, access to credit and food insecurity had a negative influence. Our results reveal PIs of 41%, 49%, and 42% at the planning, implementation, and M&E stages respectively, indicating a moderate participation level. The fractional regression model shows that transaction costs associated with access to markets, gender (being male), household expenditure and expected forest benefits positively influence household participation in PFM, while the opportunity costs associated with off-farm income, distance to the forest and lack of extension have a negative influence on participation. These results point to the need to take the household context (gender, education, household expenditure and vulnerability) into consideration during planning and implementation of the forestry programs. The implication is that forest authorities should identify and implement mechanisms to enhance benefits from forests but also reduce costs of participation, especially for women.

Assessment of land use and land cover changes in Kenya’s Mt. Elgon forest ecosystem

AbstractCurrent land‐use trends in Kenya's montane forest ecosystems show that land uses are changing fast due to natural and anthropogenic factors and these changes could have devastating effects on the environment. One such montane forest is the transboundary Mt. Elgon forest located in western Kenya. This study analysed trends in land use–land cover changes in Mt. Elgon forest ecosystem over the last 45 years. Landsat imageries downloaded from the United States Geological Survey archives were used to assess land use–land cover changes between 1973 and 2019 by applying supervised classification using Arc GIS 10.5. The IDRISI Selva 17.0 was used to calculate area under different land uses and generate change maps. The major Land Use–Land Cover (LULC) classified were mixed farming, natural forests, planted forests, bamboo forest, fallow land, tea plantation. The landsat images had an average overall classification accuracy of 87.12% and kappa coefficient (K) of 0.84. The kappa coefficient was rated as substantial and the classified images qualified for further analysis. Results established that there was an 18% decline in the natural forest cover between 1977 and 2019. There was a similar decline of 15.19% in bamboo forest cover. Plantation forests established in the 1990's also showed a 15.6% decline between 1999 and 2019. There was, however, a 29% increase in mixed farming, a 10% increase in fallow land and a 0.13% increase in tea plantations. These changes in land uses and land cover call for an urgent need to develop sustainable management plans to protect and conserve the Mt. Elgon forest ecosystem. Sustainable land management strategies to be used in the future may include education on the significance of the forest ecosystem, community participation in sustainable utilisation of forest eco‐services and the introduction of sustainable alternative sources of livelihoods, such as bee farming.

Land Use Changes and Impacts on Livelihoods of the Communities Adjacent to Mt Elgon Forest Ecosystem

Forests play a critical role in providing essential goods and services to forest adjacent communities. There is, however, insufficient information on how land uses affect the availability and use of forest products and services by forest adjacent communities. This study analysed the impacts of land use changes on the livelihoods of Mt Elgon forests adjacent communities. Land use changes were assessed for the period 1977-2019 segmented into four time periods corresponding to remote sensing data obtained for the years 1977, 1986, 1999 and 2019. Household surveys were conducted using structured questionnaires administered to 387 respondents. The questionnaires assessed how changes in land uses has impacted livelihoods. Analysis of data revealed that between 1977 and 2019, the size of land under natural forest has declined by 18%, bamboo declined by 15% while grasslands declined by 13%. On the contrary, the size of land under mixed farming and fallow increased by 30% and 27% respectively. Majority of the households (91%) were affirmative that they obtained products from Mt Elgon forest pointing to the importance of the forest to the communities living adjacent to the forest. Households closer to the forest were more reliant on the forest than those that lived farther away. The use of forest resources has been declining from 1970s with herbal medicine, game meat and wild fruits experiencing the highest decline of 28%, 27% and 24% respectively. The high dependency of the forest-adjacent communities on the Mt. Elgon forests call for enhanced conservation of the forest ecosystem and sustainable utilization of forest resources.

Factors Influencing Good Governance in Forest Management and Protection: A Case Study of Mt. Elgon Forest Reserve, Kenya

Despite the socio-economic and environmental benefits of forests globally, these ecosystems have been degraded due to poor governance. Effective governance in the forest sector calls for the identification of concrete elements within the administrative sector by systematically analysing the current situation and direct efforts towards improving the systems. A functional governing system would promote positive changes and progress by identifying challenges and gaps and come up with guidelines geared towards strengthening global co-operation. Our study explored the various factors influencing effective governance in forest management and protection in Kenya, using the case of Mt. Elgon Forest Reserve. Purposive sampling design was used to collect data through structured questionnaires and interactive interviews among forest managers, forest adjacent communities and other relevant stakeholders. The study shows that majority of the local communities living adjacent to the forest have been sensitized about forest conservation, however, the capacity building did not entail technical forestry operations. This has hampered effective involvement of the communities in forest management. Majority of the forest management staff are well trained in forest management and therefore could implement sustainable management strategies, however, due to insufficient fund, these strategies could not be fully implemented. Most of the members of the local communities are not economically empowered and mainly derive their livelihood from the forest leading to overexploitation. This strains sustainable utilization of the forest resources. Cultural practices such as livestock grazing and living within the forest are hampering sustainable management of the forest. The study suggests that successful management of the forest is limited by inadequate involvement of local communities. This has led to apathy and degradation of the forest by members who feel that their views are not sort in the management of the forest. The study recommends multi-sectoral planning and representation of sectors involved in forest management and conservation Keywords: participatory forest management, forest adjacent communities, forest products, sustainable forest management DOI: 10.7176/JESD/11-12-06 Publication date: June 30th 2020

Ecosystem-based Adaptation to Climate Change – Policy Making and Institutional Framework in Kenya’s Mt. Elgon Forest Ecosystem

Ecosystem-based Adaptation (EbA) is a strategy that relies on forest landscape’s biodiversity management and restoration to enhance the sustainable production and supply of ecosystem goods and services as alternative livelihoods to cushion the society against the negative impacts of climate change. As climate change becomes a reality, adaptation measures which are cost effective and economically beneficial are urgently required. Mount Elgon ecosystem in the western region of Kenya has EbA characteristics which could offer longer term solutions to adaptation to climate change impacts while providing a range of other benefits in terms of ecosystem goods and services. This paper established the existing capacities for Ecosystem based adaptation inclusion in the sub-national adaptation plans and policies in order to improve resilience to climate change impacts in the Mt. Elgon ecosystem. To achieve this, a descriptive survey was carried involving 405 household and 51 government and civil society respondent drawn from Saboti, Kiminini, Endebess and Kwanza sub-counties, Transnzoia County in Kenya. Results showed that there were good institutional representations in Mt. Elgon ecosystem with line ministries largely being responsible (63.4%) for the management of the individual natural resources that occur in the Mt. Elgon ecosystem while a few others were either co-managed (9.7%) or managed by the County Government of Transnzoia (9.7%). Majority (77%) of household respondents observed uncoordinated approach in ecosystem management. This should be addressed in order to increase ecosystem health which eventually leads to enhanced EbA services. Majority (73.2%) of government and civil society respondents cite inter-sectoral policy inconsistencies and conflicts as contributors to degradation of ecosystem health in the study area. This too has impacted negatively on EbA. A major conclusion in the study was that consolidation and harmonization of ecosystem policies in the Mt. Elgon’s ecosystem will lead to a healthy landscape that provides sustainable EbA services.

Influence of Deforestation Activities on Sustainable Livelihoods of the Inhabitants in Mount Elgon Forest Reserve, Bungoma County, Kenya

In the last three decades, the Mount Elgon Forest in Kenya has declined primarily due to anthropogenic activities as a result of overdependence of forest products and services for livelihoods. This paper aimed at investigating the influence of deforestation activities on sustainable livelihoods of the inhabitants in mount Elgon Forest. This study used cross-sectional research design and mixed methodology where both quantitative and qualitative approaches of data collection and analysis was used. The target population was 12842 household heads, 4 ward administrators, 12 chiefs, 1 Kenya Forest service personnel and 1 NEMA official. A sample of 373 household heads,4 ward administrators, 12 chiefs, 1 Kenya Forest Service Personnel and 1 NEMA official took part in the study. Questionnaires, interview guides and Focus Group Discussions were used to collect data. Validity was determined by consulting supervisors while reliability was ascertained using Cronbach Alpha Coefficient. The quantitative data was analysed using frequencies, percentages, mean and Standard deviation. Pearson Correlation analysis was employed to determine relationship that exists between the independent and dependent variables. Qualitative data was thematically classified and arranged before they are reported in narrations and quotations. Analyzed data was presented using tables and figures. The study found out that there was a significant positive correlation between deforestation activities and sustainable households’ livelihoods (r = .682; p = .000) showing that deforestation activities affect sustainable livelihoods. It was recommended that there is need for the community and the government agencies to devise strategies of enhancing sustainable use of forest resources.

Variation of Nutrients and Functional Properties within Young Shoots of a Bamboo Species (Yushania alpina) Growing at Mt. Elgon Region in Western Kenya

Yushania alpina is an indigenous bamboo species growing at Mt. Elgon forest in Western Kenya and its young shoots are consumed by the local people as a vegetable. This study was done to determine some physico-chemical properties and their distribution within the shoot. Each shoot was divided into the upper and lower portions which were analyzed separately, and results were expressed in dry weight basis. On proximate composition, there was no significant difference (p<0.05) between the two portions in terms of moisture, protein, ash and fat content, which ranged 92.2-92.4% fresh weight, 33.0-33.4% dry weight basis (dwb), 17.0-17.1% dwb and 2.0% dwb, respectively. Significant difference was found in fiber and carbohydrates, whose content was 23.9 and 23.6% dwb in the upper portion compared to 30.7 and 17.3% dwb in the lower part, respectively. The upper portion contained Ca of 2,670, Mg of 4,300, K of 35,900 and P of 7,630 µg/g dwb, whereas the lower portion had Ca of 1,060, Mg of 1,270, K of 27,600 and P of 4,810 µg/g dwb. The upper portion was found to contain thiamine, riboflavin and vitamin C of 2.2, 8.4 and 78.2 µg/g dwb, respectively, whereas the lower part contained 1.8, 7.3 and 51.2 µg/g dwb, respectively. Fructose was found to differ significantly with the upper portion having 2.19 % against 0.62 % in the lower portion. Total polyphenol and flavonoid content of 27.6 and 24.6 mg/g dwb, respectively, were observed in the upper part compared to 25.9 and 20.1 mg/g dwb, respectively in the lower part. The upper portion was observed to exhibit better antioxidant activity with LC50 of 1 mg/ml compared to 5 mg/ml for the lower part, and higher Hunter’s L* value.

Ecological and Socio-Economic Contribution of Mt. Elgon Forest Park, Eastern Uganda

This paper explores the ecological and socio-economic contribution of Mt. Elgon forest park, eastern Uganda. An effort was taken to evaluate the importance of Mt. Elgon forest park resources to the local people by using the local plant knowledge to value the forest park resources. An integrated approach of participatory rural appraisal (PRA), Participatory Resource Valuation (PRV), household survey, group discussions and forest walks were conducted during the months of June to December, 2008 in Mutushet and Kortek Parishes, Kapchorwa District. Using random sampling methods, 120 respondents were selected and interviewed. Ten forest uses were identified with the highest dependence being in the supply of timber for income and domestic building poles, the latter having the highest average annual household value of UGx. 67919 (US$37). The forest use most valued in both Mutushet and Koterk was medicine with an average annual household value of UGx. 60,371 (US$ 33) and UGx. 75,464 (US$ 42) respectively. The forest provision of medicine, domestic building materials, soil conservation, bush meat, charcoal and timber was more valued in Koterk, while provision of firewood, honey and pasture were more valued in Mutushet. The forest’s provision of food was valued equally in the two areas with an average annual value of UGx. 30,186 per household. Forest park resources accounted for 55% of the household income. Participatory valuation approaches are ecommended for estimation of forest park resources’ value in a non-cash economy.

Complex contexts and dynamic drivers: Understanding four decades of forest loss and recovery in an East African protected area

Protected forests are sometimes encroached by surrounding communities. But patterns of cover change can vary even within one given setting – understanding these complexities can offer insights into the effective maintenance of forest cover. Using satellite image analyses together with historical information, population census data and interviews with local informants, we analysed the drivers of forest cover change in three periods between 1973 and 2009 on Mt Elgon, Uganda. More than 25% of the forest cover of the Mt Elgon Forest Reserve/National Park was lost in 35years. In periods when law enforcement was weaker, forest clearing was greatest in areas combining a dense population and people who had become relatively wealthy from coffee production. Once stronger law enforcement was re-established forest recovered in most places. Collaborative management agreements between communities and the park authorities were associated with better forest recovery, but deforestation continued in other areas with persistent conflicts about park boundaries. These conflicts were associated with profitability of annual crops and political interference. The interplay of factors originating at larger scales (government policy, market demand, political agendas and community engagement) resulted in a “back-and-forth” of clearing and regrowth. Our study reveals that the context (e.g. law enforcement, collaborative management, political interference) under which drivers such as population, wealth, market access and commodity prices operate, rather than the drivers per se, determines impacts on forest cover. Conservation and development interventions need to recognize and address local factors within the context and conditionalities generated by larger scale external influences.

Disturbance indicators and population decline of logged species in Mt. Elgon Forest, Kenya

AbstractMount (Mt) Elgon forest in western Kenya is important for biodiversity, environmental protection and socio‐economic development. Characterizing forest conditions is essential for evaluation of sustainable management and conservation activities. This paper covers findings of a study which determined and analysed indicators useful in monitoring disturbance levels in the Mt Elgon Forest. A systematic survey was carried out and covered 305 plots of 0.02 ha and 250 smaller nested regeneration plots along 10 belt transects that were distributed in five blocks within the moist lower montane forest type. Collected and analysed data include types of disturbance, tree species composition, abundance and logged species. Correlation breakdown among disturbance types revealed that, paths were indicators of the number of tree harvesting sites (rs =1.00, P &lt; 0.01) and of de‐vegetated areas through grass harvesting (rs = 0.90, P = 0.04). Solanum mauritianum Scop. was an indicator of old‐charcoal production sites. Logging targeted 13 tree species and harvested trees with diameter at breast height above 20 cm. The most exploited species were Olea capensis L. and Deinbolia kilimandscharica Taub. All exploited species had low regeneration but tree regeneration was not an effective indicator of logging.

Interactions amongst trees and crops in taungya systems of western Kenya

Lack of empirical data on the effects of the taungya system on establishment and early growth of softwood plantations have partly contributed to controversial decisions regarding the continued suitability of the system for plantation establishment in Kenya. This study examined effectiveness of taungya systems of forest plantation establishment using Cupressus lusitanica and Pinus patula trees with Zea mays (maize) as a test intercrop on two contrasting site types (deep and shallow soils) in Mt. Elgon forest, western Kenya . Four treatments were evaluated in each site: trees with or without weed control, trees intercropped with maize, and sole maize. Results showed that tree survival, growth and nutrient uptake, and maize growth and yield were higher in the deep soil site than the shallow site. The taungya system improved tree survival and growth, effects being greater in the deep than the shallow soil site. Both Cupressus lusitanica and Pinus patula trees had the same effects on maize growth and yield, reducing maize growth by 41–48% in the deep soil sites, and by 16–26% in the shallow site. Vector nutrient analysis and vector competition analysis of the treatment effects on growth and nutrient uptake of the trees and the maize crop suggested competition for N on the deep soils, but competition for K and P on the shallow soils. The study has demonstrated the applicability of graphical vector competition analysis in diagnosing tree–crop interactions in agroforestry.

Diversity and distribution of wild terrestrial orchids of Mt Elgon Forest National Park, eastern Uganda

AbstractThe diversity and distribution of wild terrestrial orchids of Mt Elgon National Park was studied between November 2003 and November 2004. The vegetation types investigated were grasslands, montane, bamboo, heath and moorlands. Sampling was done along Piswa and Sasa trails in the rainy and dry seasons. Altitude, slope gradient position, vegetation disturbance, burning and percentage canopy were assessed to find their influence on species diversity and distribution. Eighteen terrestrial orchids’ species were recorded. These represented four tribes and eight genera. Habenaria was the most frequent and dominant genus accounting for 44.4% of all the species encountered. Species dominance was more pronounced in the dry season. Along Sasa trail, Disa stairsii Kraenzl dominated the bamboo and heath vegetation zones. Epipactis africana Rendle dominated the montane vegetation zone. Along Piswa trail, Eulophia angolensis Rchb.f. dominated the grassland vegetation zone, while D. stairsii dominated in the montane and heath vegetation zones. Species diversity, frequency of occurrence and density were higher in the rainy season than in the dry season in all vegetation types. Canonical correspondence analysis revealed that altitude, slope gradient position and percentage canopy cover were important factors that influenced orchid species richness and distribution.

Forest structure characteristics in disturbed and undisturbed sites of Mt. Elgon Moist Lower Montane Forest, western Kenya

This paper, reports results of an ecological study carried out in Mt. Elgon moist lower montane forest, Kenya. The vertical and horizontal structure of the forest was investigated in a bid to better understand the ecological state and management needs of the forest. The assessed forest attributes were (1) stocking levels, (2) diameter size distribution structure for all tree species combined and for five dominant tree species individually, (3) vertical stratification—vegetation layers identification and differentiation, canopy continuity and foliage dispersion. Forest sampling was done in both heavily and lightly logged-over sites. From the results, Mt. Elgon moist lower montane forest can be classified as an under-stocked tropical mixed rain forest. Tree densities varied among sites either as a result of logging, site quality or both. Diameter size for all species combined followed the reverse J -curve, typical of uneven-aged mixed forests. Regeneration and recruitment patterns of the forest and of individual tree species varied among sites; and in spite of a good overall forest regeneration, this did not necessarily mirror the regeneration status of constituent tree species. Both vertical and horizontal forest structure characteristics seem to suggest a building phase for the forest. Data reveal a forest canopy characterized by dispersed foliage intersected by forest gaps (±200 m 2 ) leading to thick and continuous undergrowth. Elevation, logging intensity and forest development history seem to be the main factors attributable to the observed structure and regeneration of Mt. Elgon forest.

Forest structure characteristics in disturbed and undisturbed sites of Mt. Elgon Moist Lower Montane Forest, western Kenya

This paper, reports results of an ecological study carried out in Mt. Elgon moist lower montane forest, Kenya. The vertical and horizontal structure of the forest was investigated in a bid to better understand the ecological state and management needs of the forest. The assessed forest attributes were (1) stocking levels, (2) diameter size distribution structure for all tree species combined and for five dominant tree species individually, (3) vertical stratification—vegetation layers identification and differentiation, canopy continuity and foliage dispersion. Forest sampling was done in both heavily and lightly logged-over sites. From the results, Mt. Elgon moist lower montane forest can be classified as an under-stocked tropical mixed rain forest. Tree densities varied among sites either as a result of logging, site quality or both. Diameter size for all species combined followed the reverse J-curve, typical of uneven-aged mixed forests. Regeneration and recruitment patterns of the forest and of individual tree species varied among sites; and in spite of a good overall forest regeneration, this did not necessarily mirror the regeneration status of constituent tree species. Both vertical and horizontal forest structure characteristics seem to suggest a building phase for the forest. Data reveal a forest canopy characterized by dispersed foliage intersected by forest gaps (±200 m 2) leading to thick and continuous undergrowth. Elevation, logging intensity and forest development history seem to be the main factors attributable to the observed structure and regeneration of Mt. Elgon forest.