Department of Natural Resources

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290IMPACTS OF COMMUNITY ACTIVITIES ON ENVIRONMENTAL RESOURCES: THE POTENTIAL FOR DEVELOPING PAYMENT SCHEMES FOR ENVIRONMENTAL SERVICES
(VDM Dr Muller Gmbh and co, 2011-01) Kiptum, Andrew; Kipkoech, Anderson; Omondi, Humhprey; Adano, Wario R.; Osano, Odipo; iryahwaho, Byamukama B; Agasha, Annah
Natural resources have continued to be degraded largely because of lack of well-defined property rights, population pressure, high levels of poverty and the lack of proper understanding of deleterious impacts of human activities on forest and watershed resources depletion. The social cost of exploiting the resources is larger than the private benefits and individuals have incentives to excessively extract natural resources at an expense of conservation. This study considers the socio-economic aspect, farm size and activities, water availability, the distance of the agricultural activities to the edge of the forest and riverbank and agricultural management practices employed by the population in Mt. Elgon District of Western Kenya. A proxy price was obtained using hypothetical structured question on willingness to pay and willingness to accept. The sample of 236 households was used to obtain data. Field surveys, structured questionnaires, interviews with key informants, and review of secondary sources were the main tools used for data collection. Statistical package for social science (SPSS) and Excel was the main software for data analysis. The results reveal average household of 8 persons, with most households living below poverty threshold (one dollar per person per day) and on average farm size holdings of 3.105 acres per household. The results also show that most farms are within the edge of the forest and riverbank at a distance ranging about 8 km and 1 km, respectively. More than 50% of the sample population do not practice water and soil management, resulting in reduced physical properties of the water such as volume of water, turbidity, taste and smell to undesired state. The contingent value of ecosystem pricing from willingness to pay (WTP) and willingness to accept (WTA) exercise yield mean prices of the responses Ksh. 728.82 and Ksh. 6,631.44, respectively. In conclusion, the household activities of the community in Mt Elgon landscape encourage resource depletion. Therefore, adoption of sustainable agriculture and ecosystem management that consider conservation of natural resource in order to have desired qualities of the ecosystem products and to reduce the costs to the population living downstream and around are recommended. There is need to educate the local population living around the forest and watershed areas to practice sound farming practices.
An African stingless bee Plebeina hildebrandti Friese nest size and design (Apidae, Meliponini
(2016 John Wiley & Sons Ltd,, 2016) Namu, Flora N.; Wittmann, Dieter
Allometric Equations for Estimating Silk Oak (Grevillea robusta) Biomass in Agricultural Landscapes of Maragua Subcounty, Kenya
(Hindawi International Journal of Forestry Research, 2018) Mugo, Joseph Mware; Kinyanjui, Mwangi James; Owate, Omamo Augustine
Grevillea robusta is widely interplanted with crops in Maragua subcounty, a practice that enhances biomass quantities in farmlands. However, quick tools for estimating biomass of such trees are lacking resulting in undervaluation of the farm product. This study sought to develop allometric equations for estimating tree biomass using diameter at breast height (DBH) and tree height as predictor variables. Tree biomass was computed using thirty-three (33) trees randomly selected from 12 one hectare plots established in each of the four agroecological zones (AEZs). DBH of all Grevillea robusta trees per plot was measured and three trees were selected for destructive sampling to cover the variety of tree sizes. Regression analysis was used to develop equations relating DBH/tree height to biomass based on linear, exponential, power, and polynomial functions. Te polynomial and the power equations had the highest R2 , lowest SEE, and MRE values, while DBH was the most suitable parameter for estimating tree biomass. Te tree stem, branches, foliage, and roots biomass comprised 56.89%, 14.11%, 6.67%, and 22.32% of the total tree biomass, respectively. Te mean tree biomass density (12.430±1.84 ton ha−1) showed no signifcant diference (p=0.09) across AEZs implying no diference in G. robusta agroforestry stocks across the AEZ. Te allometric equations will support marketing of tree products by farmers and therefore better conservation and management of the tree resource.
Allometric Equations for Estimating Silk Oak (Grevillea robusta) Biomass in Agricultural Landscapes of Maragua Subcounty, Kenya
(Hindawi International Journal of Forestry Research, 2018-10-02) Mugo, Joseph Mware; Mwangi, James Kinyanjui; Omamo, Augustine Owate
Grevillearobusta is widely interplanted with crops in Maragua subcounty,a practice that enhances biomass quantities in farmlands. However, quick tools for estimating biomass of such trees are lacking resulting in undervaluation of the farm product. This study sought to develop allometric equations for estimating tree biomass using diameter at breast height (DBH) and tree height as predictor variables. Tree biomass was computed using thirty-three (33) trees randomly selected from 12 one hectare plots established in each of the four agroecological zones (AEZs). DBH of all Grevillea robusta trees per plot was measured and three trees were selected for destructive sampling to cover the variety of tree sizes. Regression analysis was used to develop equations relating DBH/tree height to biomass based on linear, exponential, power, and polynomial functions. The polynomial and the power equations had the highest R2, lowest SEE, and MRE values, while DBH was the most suitable parameter for estimating tree biomass. The tree stem, branches, foliage, and roots biomass comprised 56.89%, 14.11%, 6.67%, and 22.32% of the total tree biomass,respectively.Themeantreebiomassdensity(12.430±1.84tonha−1)showednosignificantdifference(p=0.09)acrossAEZs implyingnodifferenceinG.robustaagroforestrystocksacrosstheAEZ.Theallometricequationswillsupportmarketingoftree productsbyfarmersandthereforebetterconservationandmanagementofthetreeresource.
Anthropogenic activities affect forest structure and arthropod abundance in a Kenyan biodiversity hotspot
(2023-07) Kung'u, Gladys Nyakeru; Cousseau, Laurence; Githiru, Mwangi; Habel, Jan Christian
Land-use change remains the main threat to tropical forests and their dependent fauna and flora, and degradation of existing forest remnants will further accelerate species loss. Forest degradation may result directly from human forest use or through spatial effects of land-use change. Understanding the drivers of forest degradation and its effects on biodiversity is pivotal for formulating impactful forest management and monitoring protocols, but such knowledge is lacking for many biodiversity hotspots, such as the Taita Hills in southeast Kenya. Here we first quantify effects of social factors (human activity and presence) at plot and landscape level, forest management (gazetted vs. non-gazetted) and spatial factors (fragment size and distance to forest edge) on the vegetation structure of indigenous Taita forest fragments. Next, we quantify effects of degraded vegetation structure on arthropod abundance and diversity. We show that human presence and activity at both the plot and landscape level explain variation in vegetation structure. We particularly provide evidence that despite a national ban on cutting of indigenous trees, poaching of pole-sized trees for subsistence use may be simplifying vegetation structure, with the strongest effects in edge-dominated, small forest fragments. Furthermore, we found support for a positive effect of vegetation structure on arthropod abundance, although the effect of daily maximum temperature and yearly variation was more pronounced. Maintenance of multi-layered forest vegetation in addition to reforestation maybe a key to conservation of the endangered and endemic fauna of the Taita Hills.
Are stingless bees the primary vector in spread of banana Xanthomonas wilt in Central Uganda?
(International Journal of Ecology and Ecosolution, 2014-09) Namu, Flora, N.; Wittmann, Dieter
Stingless bees were speculated to be the primary vectors in the spread of the bacterial agent responsible for banana Xanthomonas wilt (BXW) in Uganda. It was hypothesized that the vector entered the banana plant through the male flowers. We therefore determined the likely role of the bees in spread of Xanthomonas campestris pv. musacearum that causes BXW. We first documented species of stingless bees present in the banana farms, their nesting sites and foraging behavior. Then we documented the foraging behavior of Hypotrigona gribodoi - Magretti and Plebeina hildebrandti Friese reared in wooden observation hives where we offered banana sap, bacterial ooze and nectar. We then measured sugar concentration in Pisang Awak, the banana variety reported to be most susceptible to Xanthomonas. We tested how far stingless bees would fly to collect banana nectar through indirect recruitment experiments to experimental feeders with 11, 33, 48 and 54% sugar solutions. Our findings were: four species of stingless bees, Hypotrigona gribodoi, Plebeina hildebrandti, Meliponula ferruginea Lepeletier and Meliponula sp. foraged and nested within the banana farms. They collected nectar from both male and female banana flowers but spent more time on female flowers than on male flowers. They did not collect banana sap and bacterial ooze from scars of recently dehisced male flowers and at the nest entrance of the observation hives. The foraging distance of workers of P. hildebrandti was 1050 and 1215 m when sugar solutions 11 and 33% were offered, respectively. The foragers would therefore fly less than 1215 m from the nest to collect Pisang Awak nectar which had an average sugar concentration of 12.5%. Thus stingless bees were likely to get accidental contamination with Xanthomonas campestris pv. musacearum just like any other moving object or insects. If the bees got accidentally contaminated with Xanthomonas, saps and resins within the nest would decontaminate them.
Assessment of drivers of forest changes using multi-temporal analysis and boosted regression trees model: a case study of Nyeri County, Central Region of Kenya
(Modeling Earth Systems and Environment, 2020-05-06) Mwangi, Nancy; Waithaka, Hunja; Mutua, Felix; Mundia, Charles; Kinyanjui, Mwangi
The Central Region of Kenya has undergone significant changes in land cover due to a broad range of drivers. These changes are more pronounced in forestland conversions. Past researches within the study area have identified drivers of land cover change without quantifying the influence of these drivers. Predictor variables include population density, precipitation, elevation, slope, forest fires, soil texture, proximity to roads, rives and towns. Land cover changes were analyzed using multi-temporal land cover maps between year 1990 and 2014. Boosted regression trees model was applied to determine the significant drivers and quantify their relative influence on key forestland transitions. The local and spatial influence of the drivers has further been analyzed by geographical weighted regression using coefficients determined at each sample point. Significant land cover changes continuously occurred over the study period. Forestland reduced from 38.90% in 1990 to 38.14% in 2014. Grassland reduced from 32.59 to 22.57%, cropland increased from 28.05 to 38.83% and wetland changed from 0.07 to 0.04%. Other land which constitutes of bare land and built up increased from 0.38 to 0.42%. The results show population density had the highest contribution to forestland changes throughout the study period, with a minimum contribution of 20.02% to a maximum of 26.04%. Other significant variables over the study period are precipitation, slope, elevation and the proximity variables. The results indicate that the relative influence of the drivers to forestland conversion varies with time, location and type of transition.
The Biological Assessment and Rehabilitation of the World’s Rivers: An Overview
(Water, 2021-01-31) Feio, Maria João; Hughes, Robert M.; Callisto, Marcos; Nichols, Susan J.; Odume, Oghenekaro N.; Quintella, Bernardo R.; Kuemmerlen, Mathias; Aguiar, Francisca C.; Almeida, Salomé F.P.; EguíaLis, Perla Alonso; Arimoro, Francis O.; Dyer, Fiona J.; Harding, Jon S.; Jang, Sukhwan; Kaufmann, Philip R.; Lee, Samhee; Li, Jianhua; Macedo, Diego R.; Mendes, Ana; Mercado-Silva, Norman; Monk, Wendy; Nakamura, Keigo; Ndiritu, George G.; Ogden, Ralph; Peat, Michael; Reynoldson, Trefor B.; Rios-Touma, Blanca; Segurado, Pedro; Yates, Adam G.
The biological assessment of rivers i.e., their assessment through use of aquatic assemblages, integrates the effects of multiple-stressors on these systems over time and is essential to evaluate ecosystem condition and establish recovery measures. It has been undertaken in many countries since the 1990s, but not globally. And where national or multi-national monitoring networks have gathered large amounts of data, the poor water body classifications have not necessarily resulted in the rehabilitation of rivers. Thus, here we aimed to identify major gaps in the biological assessment and rehabilitation of rivers worldwide by focusing on the best examples in Asia, Europe, Oceania, and North, Central, and South America. Our study showed that it is not possible so far to draw a world map of the ecological quality of rivers. Biological assessment of rivers and streams is only implemented officially nation-wide and regularly in the European Union, Japan, Republic of Korea, South Africa, and the USA. In Australia, Canada, China, New Zealand, and Singapore it has been implemented officially at the state/province level (in some cases using common protocols) or in major catchments or even only once at the national level to define reference conditions (Australia). In other cases, biological monitoring is driven by a specific problem, impact assessments, water licenses, or the need to rehabilitate a river or a river section (as in Brazil, South Korea, China, Canada, Japan, Australia). In some countries monitoring programs have only been explored by research teams mostly at the catchment or local level (e.g., Brazil, Mexico, Chile, China, India, Malaysia, Thailand, Vietnam) or implemented by citizen science groups (e.g., Southern Africa, Gambia, East Africa, Australia, Brazil, Canada). The existing large-extent assessments show a striking loss of biodiversity in the last 2–3 decades in Japanese and New Zealand rivers (e.g., 42% and 70% of fish species threatened or endangered, respectively). A poor condition (below Good condition) exists in 25% of South Korean rivers, half of the European water bodies, and 44% of USA rivers, while in Australia 30% of the reaches sampled were significantly impaired in 2006. Regarding river rehabilitation, the greatest implementation has occurred in North America, Australia, Northern Europe, Japan, Singapore, and the Republic of Korea. Most rehabilitation measures have been related to improving water quality and river connectivity for fish or the improvement of riparian vegetation. The limited extent of most rehabilitation measures (i.e., not considering the entire catchment) often constrains the improvement of biological condition. Yet, many rehabilitation projects also lack pre-and/or post-monitoring of ecological condition, which prevents assessing the success and shortcomings of the recovery measures. Economic constraints are the most cited limitation for implementing monitoring programs and rehabilitation actions, followed by technical limitations, limited knowledge of the fauna and flora and their life-history traits (especially in Africa, South America and Mexico), and poor awareness by decision-makers. On the other hand, citizen involvement is recognized as key to the success and sustainability of rehabilitation projects. Thus, establishing rehabilitation needs, defining clear goals, tracking progress towards achieving them, and involving local populations and stakeholders are key recommendations for rehabilitation projects (Table 1). Large-extent and long-term monitoring programs are also essential to provide a realistic overview of the condition of rivers worldwide. Soon, the use of DNA biological samples and eDNA to investigate aquatic diversity could contribute to reducing costs and thus increase monitoring efforts and a more complete assessment of biodiversity. Finally, we propose developing transcontinental teams to elaborate and improve technical guidelines for implementing biological monitoring programs and river rehabilitation and establishing common Water 2021, 13, 371 3 of 45 financial and technical frameworks for managing international catchments. We also recommend providing such expert teams through the United Nations Environment Program to aid the extension of biomonitoring, bioassessment, and river rehabilitation knowledge globally.
Biomass Energy Resource of the Highland Bamboo (Yushania alpina) and Its Potential for Sustainable Exploitation in Southern Aberdares Forest
(Scientific Research Publishing Inc., 2017) Kinyanjui, Mwangi James; Katumbi, Ndirangu Monicah; Kimondo, JM; Mware, Mugo Joseph
Yushania alpina is the only bamboo species native to Kenya and covers about 150,000 ha growing in pure or mixed stands in the montane forests. The Aberdare forest is one of the natural habitats for Y. alpine occupying an area of 6419 ha mainly in the water catchment areas. The growing human population and depletion of other forest resources have necessitated the exploration of Y. alpine as a source of energy. This paper assessed the quantity of Y. alpine available for biomass energy and its potential for sustainable exploitation. Plots were laid on area maps to cater for altitude and distance from farms. The study area was stratified into three altitudinal zones: A (2220 - 2330 m), B (2331 - 2440 m) and C (2441 - 2550 m). The initial sampling plot of 10 m × 10 m was located randomly 500 m from the edge of the forest while the subsequent plots were laid out systematically at intervals of 500 m. In each plot, a total enumeration and biomass estimation of bamboo clumps were done using Muchiri and Muga (2013) [1] method. Bamboo samples and those of commonly used biomass energy sources were analysed for calorific value using bomb calorimeter. In addition, data for quantities of biomass energy used by some local industries were used to estimate the amount of bamboo required. The mean stocking was 19,981 (20,000) culms ha−1, and varied significantly among altitude strata and distance from adjacent farms. The mean biomass density and energy content were 86 tons/ha and 380,893 Kca/ha respectively with the higher altitudinal stratum (zone C) having the highest means (114 tons/ha) while the lower stratum (zone A) had the lowest (65 tons/ha). Theenergy needed by sampled local industries was 416,276,266 Kcal per year against 2.4 billion Kcal available in the bamboo forest. This implies that the bamboo forest in its present stocking can provide biomass energy for these local industries for more than five years. With bamboo maturing with less than five years, the forest can sustainably provide the required energy while still providing its environmental services.
Challenges of Elephant Conservation: Insights from Oral Histories of Colonialism and Landscape in Tsavo, Kenya
(American Geographical Society, 2018) Kamau, Peter Ngugi; Sluyter, Andrew
Understanding the reasons for conflict between elephants and people who live adjacent to conservation areas remains key to recruiting them as allies in preserving elephant populations. The Tsavo region of Kenya has become a notable battleground for elephant conservation in East Africa, characterized by ivory poachers, crop damages by elephants in communities adjacent to parks, and electric fencing to control human and wildlife mobility. Oral histories of six ethnic groups reveal how such human-elephant conflict emerged during colonial times through a landscape transformation process involving elephants, livestock, people, and vegetation. The general trend over the past two centuries involves a transition from a precolonial modality characterized by human and elephant mobility to their increasing immobility, spatial separation, and conflict. Understanding of the historical emergence of that conflict forces recommendation of a change in policy direction, from further reducing mobility to restoration of mobility and spatial reintegration of people in parks. Keywords: colonialism and landscape, East Africa, elephant conservation, historical political ecology.
Challenges of elephant conservation: insights from oral histories of colonialism and landscape in Tsavo, Kenya
(American Geographical Society, 2017) Kamau, Peter Ngugi; Sluyter, Andrew
Understanding the reasons for conﬂict between elephants and people who live adjacent to conservation areas remains key to recruiting them as allies in preserving elephant populations. The Tsavo region of Kenya has become a notable battleground for elephant conservation in East Africa, characterized by ivory poachers, crop damages by elephants in communities adjacent to parks, and electric fencing to control human and wildlife mobility. Oral histories of six ethnic groups reveal how such human-elephant conﬂict emerged during colonial times through a landscape transformation process involving elephants, livestock, people, and vegetation. The general trend over the past two centuries involves a transition from a precolonial modality characterized by human and elephant mobility to their increasing immobility, spatial separation, and conﬂict. Understanding of the historical emergence of that conﬂict forces recommendation of a change in policy direction, from further reducing mobility to restoration of mobility and spatial reintegration of people in parks
The challenges of wild game on forest plantations management objectives in forest ecosystems in kenya
(Emerging Academy Resources, 2013) Mugo, Mware J.; Mutiso, Festus M.; Cheboiwo, Joshua K.; Sang, Francis; Tarus, George K.; Chemitei, Gideon K.
Forests in Africa and Asia host various wildlife populations that cause varying levels of damages to forest resources. The economic damage is more severe in forest plantations meant for timber production that require huge financial outlays. Like many countries most forest ecosystems in Kenya contain many forest plantations and wild game conservation units. Despite the heavy losses to plantation crops by wild game, the extent of the loss as well as existence of a balance between wild game conservation and plantation forestry remains unknown. The study therefore attempts to deepen the knowledge on the impacts of game damage on forest ecosystems in particular plantations and also provide some option to forest managers to counter minimize damage levels. To minimize wild game damages in Key ecosystems of Mt. Kenya and Aberdares in Kenya game moats were constructed. Recently, electric fences were introduced into parts of the Aberdares to keep away wild animals from plantations and farms. The use of physical structures has been successful in reducing damage from large game such as elephants and buffaloes but controlling smaller game mostly monkeys, porcupines, and moles remain a challenge. This paper focuses on the benefits and challenges of restricting wild game movement in forest plantations management as well as the ecological and economic impacts in Mt Kenya and Aberdare ecosystems. The study was carried out through assessments of the damage intensity of foliage, tree limb breakages and bark damages of major plantation species in the age cohorts 5-10, 11-20 and > 20 years old. Damage attribution by specific group of game was evaluated to establish their overall contribution to forest plantation damages. The study results show that individual site damages were statistically different (P < 0.05) but had a weak Pearson correlation (rs = 0.46, n = 8, P = 0.05). The Duncan Multiple Range Test (DMRT) showed significant statistical differences in the two ecosystems but exhibited a strong negative correlation (rs = 0.97, n = 8, p < 0.05) in the prevalence of the causative animals . The Spearman Correlation Analysis on the prevalence of damages across the species showed a strong positive correlation (rs = +0.88, n = 8, P < 0.05). The economic production of plantation forests was found not to be compatible with wild game conservation but degree differed within the two ecosystems. In Mt Kenya, where plantations are not well protected from wild game, damage was widely prevalent as compared to the well-protected Aberdares ecosystem where it was minimal. The fencing off approach significantly reduced elephant damage in the Aberdare ecosystem but the restriction caused an increase in pressure on other critical forest resources resulting in overgrazing. The electric fence has been successful in restricting large wild game in Aberdare forests and hence the need to replace nonfunctional game moats with electric fences in Mt Kenya. Concurrently, carrying out habitat enrichment with preferred diets and other fallback resources in buffer zones between production units will provide the muchneeded critical resource to destructive wild game. Other strategies explored include well-designed animals migration corridors and culling measures. The study was limited in scope to physical damage to plantation forests and hence there is need widen studies to cover economic losses and impacts on natural forests to enable development of best strategies of controlling destructive wild game in forest ecosystems.
Characterization of the nutritional quality of amaranth leaf protein concentrates and suitability of fish meal replacement in Nile tilapia feeds
(Elsevier, 2017) Okoth, Elijah Oyoo; Ngugi, Charles C.; Manyala, Julius O.; Fitzsimmons, Kevin; Kimotho, Ann
A number of leafy vegetables,their protein concentrates and hydrolasates are under evaluation as alternative protein ingredients to fish meal(FM)in aqua feeds. This study evaluated the nutritional characteristics and suitability of replacing FM with the amaranth (Amaranthus hybridus)leaf protein concentrates (ALPC) as a protein ingredient in the diet of Nile tilapia (Oreochromis niloticus). Experimental diets were formulated, where 100%, 75%, 50%, 40%, 20% and 0% FM protein was substituted by protein from ALPC. The six dietary treatments were tested in triplicate in static flow-through tanks. The substitution effects were compared in terms of fish growth performance, nutrient utilization, whole body composition and apparent nutrient digestibility. After 160 days of feeding, the growth, nutrient utilization and Feed Conversion Ratio (FCR) in fish fed diets containing 100%, 75%, 50%, 40% and 20% FM were better (P < 0.05) than those fed diet with 0% FM. The Apparent nutrient digestibility was high for protein, lipid and energy and differed significantly among the dietary treatments (P < 0.05). Protein digestibility in fish was highest in feed formulated with 100%, 75%, 50% and 40% FM, which were significantly (P < 0.05) higher than at 25% and 0% FM. Lipid digestibility was comparable for all the diets except fish fed 0% FM. Digestible carbohydrates and dry matter were similar for all dietary treatments (P < 0.05). We demonstrate that it is possible to replace up to 80% of fish meal with ALPC without compromising the performance O. niloticus. These results demonstrate that although it is possible to replace large part of fish meal with ALPC, it is not possible to eliminate it in Nile tilapia diet as alternative protein ingredient
Comparing Tree Heights among Montane Forest Blocks of Kenya Using LiDAR Data from GLAS
(Scientific Research Publishing, 2015) Kinyanjui, Mwangi James; Kigomo, Ngugi John; Kamau, Miriam Wambui; Nderitu, Joel Kariuki; Nyanjui, Charles; Nganga, John Macharia; Ojijo, William Odidi; Ashiono, Fredrick; Owate, Augustine Omamo; Ndirangu, Monicah Katumbi
This study was designed to use LiDAR data to research tree heights in montane forest blocks of Kenya. It uses a completely randomised block design to asses if differences exist in forest heights: 1) among montane forest blocks, 2) among Agro ecological zones (AEZ) within each forest block and 3) between similar AEZ in different forest blocks. Forest height data from the Geoscience Laser Altimeter System (GLAS) on the Ice Cloud and Land Elevation Satellite (ICE- SAT) for the period 2003-2009 was used for 2146 circular plots, of 0.2 - 0.25 ha in size. Results indicate that, tree height is largely influenced by Agro ecological conditions and the wetter zones have taller trees in the upper, middle and lower highlands. In the upper highland zones of limited human activity, tree heights did not vary among forest blocks. Variations in height among forest blocks and within forest blocks were exaggerated in regions of active human intervention.
Developing a Forest Management Plan (DFMP) for Gatsibo District in the Eastern Province of Rwanda
(Scientific Research Publishing Inc., 2018) Kinyanjui, Mwangi James; Rurangwa, Felix; Bazimaziki, Frederick; Peeters, Jacques; Munyehirwe, Anicet; Musoke, Francis; Habiyaremye, Gaspard Nelson; Bakundukize, Dismas; Ngabonziza, Prime; Uwase, Jost
In support of conservation of its fragile land resource, the government of Rwanda has proposed the management of all forests in the country under a specific management plan. This assignment sought to develop a management plan for the public productive forests of Gatsibo District in Eastern province of Rwanda. Data was collected from 1468 plots, proportionally allocated by size to the 375 forest stands. Information about the forest (qualitative data) was recorded and then forest measurements (inventory) done in a concentric cycle of 9.77 m and 3.99 m radius and all data recorded in a digital format using the survey CTO platform. The data was summarized and analyzed in a harmonized forest management tool for Rwanda comprising of six interlinked excel files based on Rwanda’s silvicultural regimes and treatments. This analysis resulted to planning for silvicultural activities in each forest up to the year 2070. Results show that the public plantation forests of Gatsibo are poorly stocked mainly due to poor management and the best stocked forest had a basal area of only 13.3 m2/ha. This implied low forest volumes for each of the wood requirements; timber wood, service wood and energy wood. Eucalyptus forests are the most common but are poorly stocked compared to the Pinus patula forests which are even aged by plantation. A projection of stocks shows that the forests can be sustained with an average wood volume of 73 m3/ha, to provide harvests yearly and reduce the wood supply and demand gap in the district. A viability analysis indicates that some forests are viable for leasingwith good profits in the short term (10 years) and full term planning (40 years). However, some forests may not be commercially viable due to their current stocks and agro bioclimatic conditions, and these would be rehabilitated for ecosystem services. This plan supports the restoration of the forests of Gatsibo district through provision of specific guidelines for the management of the forests.
Dietary administration of probiotics modulates non-specific immunity and gut microbiota of Nile tilapia (Oreochromis niloticus) cultured in low input ponds
(International Journal of Veterinary Science and Medicine, 2019) Ngugi, Charles C.; Jumbe, James; Opiyo, Mary A.; Charo-Karisa, Harrison
Effects of dietary levels of essential oil (EO) extract from bitter lemon (Citrus limon) fruit peels on growth, biochemical, haemato-immunological parameters and disease resistance in Juvenile Labeo victorianus ﬁngerlings challenged with Aeromonas hydrophila
(John Wiley & Sons Ltd, 2016-04) Okoth, Elijah Oyoo; Muchiri, Mucai; Ngugi, Charles C.
Essential oils (EOs) are used in the food industry because of their biological activity. We evaluated the effects of administration of essential oil (EO) extracted from bitter lemon (Citrus limon) fruit peels on the growth performance, biochemical, haemato-immunological parameters and possible disease resistance in ﬁngerlings (4 weeks old) Labeo victorianus challenged with Aeromonas hydrophila. Fish were divided into ﬁve groups and fed diets supplemented with C. limon fruit peels EO extract at 1%, 2%, 5% and 8% [as fed basis] and treatment compared with control group fed diet without C. limon fruit peels EO extract. The experiment was executed in triplicate. Concentration of plasma cortisol, glucose, triglyceride and cholesterol decreased while that of total protein and albumin increased as dietary inclusion of the EO extract of C. limon fruit peels was increased from 2% to 5%. Meanwhile haemato-immunological parameters including red blood cell (RBC), white blood cell (WBC) counts, haematocrit (Htc), mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC) and neutrophiles increased with increasing dietary inclusion from 1% to 5% inclusion of C. limon fruit peels EO extract. Serum immunoglobulins, lysozyme activity and respiratory burst increased with increasing dietary levels up to 5% inclusion of EO extract of C. limon fruit peels. We demonstrate that formulation of feeds by incorporating upto 5% the EO extract from C. limon fruit peels signiﬁcantly improved biochemical, haematological and immunological response in juvenile ﬁsh resulting to lower mortality than the untreated groups and appear to be effective antibacterial against A. hydrophila.
Encroachment of open grasslands and Acacia drepanolobium Harms ex B.Y.Sjöstedt habitats by Euclea divinorum Hiern in Ol Pejeta Conservancy, Kenya
(African Journal of Ecology , Wiley online Library, 2013-03) Wahungu, Geoffrey M.; Gichohi, Nathan, W.; Onyangi, Irene, A.; Mureu, Lucy, K.; Kamaru, Douglas; Mutisya, Samuel; Mulama, Martin; Makau, Joseph, K.; Kimuyu, Duncan, M.
Euclea divinorum, a fast establishing, unpalatable, and fire resistant bush is considered an invasive species in some parts of its range. In Ol Pejeta Conservancy (OPC), Kenya, E. divinorum bushes cover ˜27% of the total area (˜9470 ha.) and has been expanding in coverage and encroaching into A. drepanolobium woodlands, a key woody habitat for the endangered black rhino. Between 2006 and 2010, we assessed the spatial distribution, annual rates of spread and recruitment of E. divinorum in OPC. We used data from satellite imagery and belt transects laid at the transition between E. divinorum habitat and other habitats. Density of E. divinorum seedlings increased by 27% annually over five years, with more seedlings establishing in grassland habitat (56.6%) than in A. drepanolobium woodland (43.4%). Within the infection frontier, the number of seedlings was high at the ecotone and reduced predictably with an increase in distance into the infection zone. Increase in rainfall facilitated recruitment and survival of E. divinorum seedlings and also reduced damage on trees and seedlings by mega-herbivores, especially elephants. This study confirms the encroachment of E. divinorum bushland into other habitats. This has been accelerated by burning and damage to A. drepanolobium habitat thus opening it up to encroachment by E. divinorum.
Estimation of Above Ground Biomass in Forests Using Alos Palsar Data in Kericho and Aberdare Ranges
(Scientific Research Publishing, 2017) Kinyanjui, Mwangi James; Odera, Patroba Achola; Maina, Eunice Wamuyu
Above Ground Biomass is one of the six pools identified in the inventory of forest resources and estimation of greenhouse gas emissions and sinks from the forestry sector. The pool varies by management practices in different agro- ecological or agro-climatic zones in forests. The quantification of above ground biomass (AGB) hence carbon sequestration in forests has been very difficult due to the immense costs required. This research was done to estimate AGB using ALOS PALSAR L band data (HH, HV polarisation) acquired in 2009 in relation with ground measurements data in Kericho and Aberdares ranges in Kenya. Tree data information was obtained from ground measurement of DBH and tree heights in 100 circular plots of 15 m radius, by use of random sampling technique. ALOS PALSAR image is advantageous for its active microwave sensor using L-band frequency to achieve cloud free imageries, and the ability of long wavelength cross-polarization to estimate AGB accurately for tro- pical forests. The variations result between Natural and plantation forest for measured and estimated biomass in Kericho HV band regression value was 0.880 and HH band was 0.520. In Aberdare ranges HV regression value of 0.708 and HH band regression value of 0.511 for measured and estimated biomass respectively. The variations can be explained by the influence of different management regimes induced human disturbances, forest stand age, density, species composition, and trees diameter distribution. However, further research is required to investigate how strong these factors affect relationship between AGB and Alos Palsar backscatters.
Estimation of Above Ground Biomass in Forests Using Alos Palsar Data in Kericho and Aberdare Ranges
(Scientific Research Publishing, 2017) Kinyanjui, Mwangi James; Odera, Patroba Achola; Maina, Eunice Wamuyu
Above Ground Biomass is one of the six pools identified in the inventory of forest resources and estimation of greenhouse gas emissions and sinks from the forestry sector. The pool varies by management practices in different agro- ecological or agro-climatic zones in forests. The quantification of above ground biomass (AGB) hence carbon sequestration in forests has been very difficult due to the immense costs required. This research was done to estimate AGB using ALOS PALSAR L band data (HH, HV polarisation) acquired in 2009 in relation with ground measurements data in Kericho and Aberdares ranges in Kenya. Tree data information was obtained from ground measurement of DBH and tree heights in 100 circular plots of 15 m radius, by use of random sampling technique. ALOS PALSAR image is advantageous for its active microwave sensor using L-band frequency to achieve cloud free imageries, and the ability of long wavelength cross-polarization to estimate AGB accurately for tro- pical forests. The variations result between Natural and plantation forest for measured and estimated biomass in Kericho HV band regression value was 0.880 and HH band was 0.520. In Aberdare ranges HV regression value of 0.708 and HH band regression value of 0.511 for measured and estimated biomass respectively. The variations can be explained by the influence of different management regimes induced human disturbances, forest stand age, density, species composition, and trees diameter distribution. However, further research is required to investigate how strong these factors affect relationship between AGB and Alos Palsar backscatters.