School of Natural Resources and Environmental Studies

Permanent URI for this communityhttp://localhost:4000/handle/20.500.12092/1914

Browse

Now showing 1 - 20 of 134

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.
5. Absentee owners and overlapping home ranges in a territorial species
(2021-01-07) Isbell, Lynne A.; Bidner, Laura R.; Loftus, Carter; Kimuyu, Duncan M.; Young, Truman P.
Abstract Understanding animals’ use of space can shed valuable light on multiple other aspects of behavioral ecology, including social organization, dispersal, and foraging efficiency. Home ranges, territories, core areas, and home range overlaps have been widely studied, but unless animals are directly observed or are tracked remotely on a fine temporal scale, how they actually use the space available to them and how they share (or partition) this space with a community of conspecifics over time cannot be fully understood. Using GPS technology, we tracked three adjacent groups of vervet monkeys (Chlorocebus pygerythrus) in Laikipia, Kenya, for 1 year to better understand the processes involved in territoriality and home range overlaps. Home ranges overlapped with any one neighboring group by 12.7–34.7%, but intergroup encounters only occurred in restricted areas within these zones, which defined territorial boundaries. The resources closest to the territorial boundaries were nocturnal core areas with preferred sleeping sites adjacent to shortgrass areas offering fewer hiding places for ambush predators and greater visibility for predator detection. Home range overlaps were not neutral zones, the result of shifting home range boundaries over time, or based on intergroup encounters at boundaries, but resulted when groups made incursions beyond their territorial boundaries while the neighbor was far away and likely unaware of the intruders. Thus, territories can be non-exclusive but may still be perceived by the animals themselves as sole-owned, as neighbors only intrude when territory owners are absent from that area.
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, 2018-10-02) 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.
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.
Analysis of Short-Term Drought Episodes Using Sentinel-3 SLSTR Data under a Semi-Arid Climate in Lower Eastern Kenya.
(2023-06) Musyimi, Peter K.; Sahbeni, Ghada; Timár, Gábor; Weidinger, Tamas
This study uses Sentinel-3 SLSTR data to analyze short-term drought events between 2019 and 2021. It investigates the crucial role of vegetation cover, land surface temperature, and water vapor amount associated with drought over Kenya’s lower eastern counties. Therefore, three essential climate variables (ECVs) of interest were derived, namely Land Surface Temperature (LST), Fractional Vegetation Cover (FVC), and Total Column Water Vapor (TCWV). These features were analyzed for four counties between the wettest and driest episodes in 2019 and 2021. The study showed that Makueni and Taita Taveta counties had the highest density of FVC values (60–80%) in April 2019 and 2021. Machakos and Kitui counties had the lowest FVC estimates of 0% to 20% in September for both periods and between 40% and 60% during wet seasons. As FVC is a crucial land parameter for sequestering carbon and detecting soil moisture and vegetation density losses, its variation is strongly related to drought magnitude. The land surface temperature has drastically changed over time, with Kitui and Taita Taveta counties having the highest estimates above 20 ◦C in 2019. A significant spatial variation of TCWV was observed across different counties, with values less than 26 mm in Machakos county during the dry season of 2019, while Kitui and Taita Taveta counties had the highest estimates, greater than 36 mm during the wet season in 2021. Land surface temperature variation is negatively proportional to vegetation density and soil moisture content, as non-vegetated areas are expected to have lower moisture content. Overall, Sentinel-3 SLSTR products provide an efficient and promising data source for short-term drought monitoring, especially in cases where in situ measurement data are scarce. ECVs-produced maps will assist decision-makers with a better understanding of short-term drought events as well as soil moisture loss episodes that influence agriculture under arid and semi-arid climates. Furthermore, Sentinel-3 data can be used to interpret hydrological, ecological, and environmental changes and their implications under different environmental conditions.
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.
Application Of Hydrological Models In Poorly Gauged Watersheds: A Review Of The Usage Of The Soil And Water Assessment Tool (SWAT) In Kenya
(International Journal of Scientific & Technology Research, 2017-08) Mwangi, Wambugu; Nyandega, Isaiah; Kıthiia, Shadrack
In water-scarce developing countries, river basins are some of the most valued natural resources, but many are poorly gauged and have incomplete hydrological and climate records. In the recent years, tropical rivers are increasingly becoming erratic, with many hydrologists attributing this variability to combined effects of landscape-specific anthropogenic activities and climate change. Uncertainties about the impacts of climate change compound the challenges attributed to poor and often inconsistent river monitoring data. Under data-scarce conditions and with the increasing land use intensification and urbanization, modelling approaches become a useful tool in planning and management of water resources. In this paper, we review the application and usability of the Soil and Water Assessment Tool (SWAT) model in conventional planning practice in the management of water resources is poorly-gauged tropical watersheds of Kenya. We assess the technical implications of the model in Intergrated Water Resources management (IWRM) and its applicability as a planning and management tool for water resources in the era of climate change
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.
Assessing Climate Variability Adaptation and Coping Strategies Among Rural Households in Kenya
(Journal of Water Sciences & Environment Technologies, 2018-08) Nduru, Gilbert M.; Musyimi, Peter Kinyae; Huho, Julius M.; Opiyo, Francis E.
The aim of this study is to assess the adopted water scarcity adaptation and coping strategies of rural households to climate variability. It also identifies suitable strategies that minimize the impact of climate variability on water sources in arid and semi-arid (ASALs) in Kenya. The study was carried out in Makindu Sub-county, Makueni County, Kenya. Data collection techniques such as questionnaires and in-depth interview with 370 households, key informants interviews were used to assess the adaptation and coping strategies of rural households and identify the most suitable strategies for the study area. Rainfall data was collected from Makindu Meteorological station and used for meteorological drought characteristics analysis. Standardized Precipitation Index (SPI) was used to analyze drought severity in the study area between 1980 and 2011. SPI was used to quantify precipitation deficit for various time scales. Drought Intensity (DI) was used to determine decadal drought intensities. SPI results showed that 18 years out of 31 with negative SPI values an indication of drought severity occurrence. The year 2005 was the driest in the area with an SPI of -1.76. The study also showed increasing drought intensities from 1990s to 2000s. The study showed that the rural households had adopted varied adaptation and coping strategies to cope with impact of drought extremes on water sources. However, increase in drought characteristics occurrences minimized their resilience and adaptive capacities. The study observed that the strategies employed are unlikely to enable them cope with recent climate change and variability regimes, therefore need for most suitable and viable ones. The study identified viable strategies such as rainwater harvesting and sinking boreholes as long term measures that can enhance rural households’ resilience to climate change extremes in ASALs of Kenya.
Assessing Climate Variability Adaptation and Coping Strategies Among Rural Households in Kenya.
(Journal of Water Sciences & Environment Technologies, 2018) Musyimi, Peter Kinyae; Nduru, Gilbert M; Huho, Julius M; Opiyo, Francis E
The aim of this study is to assess the adopted water scarcity adaptation and coping strategies of rural households to climate variability. It also identifies suitable strategies that minimize the impact of climate variability on water sources in arid and semi-arid (ASALs) in Kenya. The study was carried out in Makindu Sub-county, Makueni County, Kenya. Data collection techniques such as questionnaires and in-depth interview with 370 households, key informants interviews were used to assess the adaptation and coping strategies of rural households and identify the most suitable strategies for the study area. Rainfall data was collected from Makindu Meteorological station and used for meteorological drought characteristics analysis. Standardized Precipitation Index (SPI) was used to analyze drought severity in the study area between 1980 and 2011. SPI was used to quantify precipitation deficit for various time scales. Drought Intensity (DI) was used to determine decadal drought intensities. SPI results showed that 18 years out of 31 with negative SPI values an indication of drought severity occurrence. The year 2005 was the driest in the area with an SPI of -1.76. The study also showed increasing drought intensities from 1990s to 2000s. The study showed that the rural households had adopted varied adaptation and coping strategies to cope with impact of drought extremes on water sources. However, increase in drought characteristics occurrences minimized their resilience and adaptive capacities. The study observed that the strategies employed are unlikely to enable them cope with recent climate change and variability regimes, therefore need for most suitable and viable ones. The study identified viable strategies such as rainwater harvesting and sinking boreholes as long term measures that can enhance rural households’ resilience to climate change extremes in ASALs of Kenya.
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.
Assessment of Growth Performance of Monosex Nile Tilapia (Oreochromis Niloticus) in Cages Using Low-Cost, Locally Produced Supplemental Feeds and Training Fish Farmers on Best Management Practices in Kenya
(2018) Bundi, James M.; Ngugi, Charles C.; Fitzsimmons, Kevin; Manyala, Julius; Kimotho, Ann N.; Amadiva, Judith M.; Ndogoni, Julius N.; Munguti, Jonathan
Changing technology in aquaculture has been the major driving force for increasing aquaculture production in the phase of dwindling open water stocks. The choice of technologies and their adoption still remain a focus to increase production, productivity and farm incomes. We assessed the growth of Nile tilapia using locally available materials that included cages and low cost feeds to increased tilapia production in ponds. Various interventions were used among them experimental trials where we formulated low cost diets replacing expensive fish meal. A series of four workshops were also conducted over the course of this project period under this intervention. The first workshop on the development and use of best management practices in aquaculture was held in August 2014. This workshop targeting women in aquaculture had 18 women in attendance. There were two subsequent workshops, held in March and August 2015, and attended by fish farmers from Kirinyaga County. The fourth workshop was held for two days between 2nd and 3rd October 2015. This workshop specifically targeted the youth in aquaculture aimed at training the youth on integrated cage and pond culture focusing on development of cage culture in reservoirs located in the county of Kirinyaga that are presently underutilized by the communities. Graduate support covered three female students who selected because of their previous linkage with AquaFish CRSP and excellent role they continue to play in development of aquaculture in this region. Among them two have submitted their theses for examination. We submitted five peer reviewed publications during this project period with two being specific on low cost feed and fish meal replacement. AquaFish provided funds for HCPIs and graduate students to attend National, Regional and WAS Meetings and Conferences as well. We note that farmers adopted feed technology very well and in their survey feed formulation and fish breeding were their priority. Under lesson learned, we noted that farmers required frequent visits, simple materials for reading and constant communication. They also require strategies on fish marketing such as use of cell phones applications and Aquashops.
Assessment of Solid waste generation and composition in Bungoma County Urban Centres for appropriate waste management approaches
(2024-08-02) Wafula, Godfrey Wekesa; Kamiri, Hellen; Ouna, Tom
The quantity and characteristics of urban solid waste are a result of the interconnectedness of diverse factors at play including social, economic, and environmental factors. These directly influence the choice of management practice at the household or community level. Understanding these relationships can help policymakers and urban planners develop more effective waste management strategies. This study aimed at assessing solid waste generation and composition in Bungoma county urban centers to inform on strategies for effective management of urban waste. The study was carried out in Bungoma County urban centers, specifically Bungoma town, Webuye, Kimilili, Kapsokwony, Chwele, and Sirisia townships. The study applied a stratified sampling technique to select the urban and peri-urban centers while random sampling was used to select respondents in residential dwellings, business people, urban residents, and officers from government institutions including public health and environment, water, and natural resources were interviewed. Ancillary data was collected using questionnaires and interview schedules while historical data was obtained from the Bungoma County Department of Environment and used to validate observed data. Data was analysed using descriptive and inferential statistics and summarized using tables, charts, and graphs. Our findings show that the highest waste was generated from residential homes, commercial, and municipal services. In terms of composition, biodegradable waste had the highest proportion, followed by plastics and glass waste. Population growth could be a key factor in the increased generation of the waste.
Attributes of Urban Greenspaces and their Influence on Visitors’ Preferences in Nairobi City County, Kenya
(Eastern African Journal of Humanities and Social Sciences Vol. 3 No. 1, 2024-07-07) Mbugua, Martin Wandie; Kamiri, Hellen; Kamau, Peter
Urban green spaces refer to land covered with vegetation such as forests, street trees, parks, gardens, and water bodies in an urban setup. In this study, we sought to investigate the attributes of urban green spaces in Nairobi County and their relationships to visitor preferences. The Garden City Model advanced by Howard (1898) guided the study. Quantitative and qualitative methods were used to collect data while a cross sectional survey designs and stratified random sampling of the green spaces was employed, based on the location within the urban core and peri-urban of Nairobi County. Four green spaces (Karura Forest, Ngong Road Forest, Nairobi Arboretum, and City Park) with diverse characteristics and attributes was selected. A sample population of 384 visitors to the green spaces were surveyed for their perceptions of the functions, use, and benefits of the green spaces. Our findings showed that attributes of green spaces including location, accessibility, security, hygiene, and infrastructure could explain the interaction between green space provision factors and the frequency of visits, time spent in the green spaces and overall satisfaction of the visitors. Green space provision should be equitable in regard to distance to residents, quality of spaces, facilities and services and should be designed to meet the needs of diverse residents. Further, they should provide services and benefits such as shade, recreation, and health which are the main attractions to the green spaces. To achieve maximum benefits for visitors, green spaces need to be safe and physically accessible to all.
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.
Biological diversity of the Yala Swamp lakes, with special emphasis on fish species composition, in relation to changes in the Lake Victoria Basin (Kenya): threats and conservation measures
(Biodiversity & Conservation, 2003-05) Aloo-Obudho, Peninah
During the second half of the last century, the Lake Victoria ecosystem has undergone drastic ecological changes. Most notable has been the decline in the populations of many endemic cichlid fishes. The lake has lost nearly 200 haplochromines and one tilapiine, Oreochromis esculentus. The above changes have been attributed to effects of species stocking and, in particular, from predation pressure by the introduced Nile perch, Lates niloticus. Other factors that have led to the decline of the endemic species include intensive non-selective fishing, extreme changes in the drainage basin, increased eutrophication, and the invasion of the lake by the water hyacinth, Eichhornia crassipes. However, the remnants of some species that had disappeared from Lake Victoria occur abundantly in the Yala Swamp lakes (Kanyaboli, Sare and Namboyo). This paper discusses the biodiversity of the swamp and the three lakes and gives suggestions for their conservation.
Biomass Energy Resource of the Highland Bamboo (Yushania alpina) and Its Potential for Sustainable Exploitation in Southern Aberdares Forest
(Scientific Research Publishing, 2017-08) Katumbi, Ndirangu Monicah; Kinyanjui, Mwangi James; JM, Kimondo; Mugo, Joseph Mware
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). The energy 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.
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.
Black Soldier Fly (Hermetia illucens) Larvae Meal as a Sustainable Protein Source for Fish Feed Production in Kenya
(SPRINGER, 2023) Opiyo, M. A.; Nairuti, R. N.; Ngugi, C. C.; Holeh, G. M.
Aquaculture has been ranked as one of the fastest-growing food sub-sectors, providing quality protein to better the livelihoods of rural communities alongside curbing malnutrition and food security globally. Nonetheless, the industry’s sustainability has been threatened by the high cost of fish feeds, which account for approximately 60–70% of the total operational costs. Fish meal (FM) has been extensively utilised as the main source of protein in the diets of farmed finfishes. However, due to declining capture fisheries and competing uses from other animal feed producers, the ingredient has become a scarce resource with limited availability and high prices. Black soldier fly larvae (BSFL) have been identified as a promising alternative protein source in fish feeds. BSFL are documented to have high nutritional content: crude protein (of up to 64% dry matter), essential amino acids, fatty acids, and other micro-nutrients which are vital for the growth of fish. BSFL meal has the potential success of replacing FM in the diets of various fish species. This chapter focuses on analysing recent research work in BSFL proximate and chemical composition, its current utilisation in fish feeds and gaps to be filled in its complete utilisation as an ingredient in commercial feed production. This information is expected to help both cottage and commercial fish feed producers utilise BSFL in feed production in Kenya and further will promote the sustainability of the aquaculture industry.