ABSTRACT The Lake Victoria Basin (LVB) rivers and streams once rich in biodiversity have been undergoing degradation over the years resulting in decline in fish productivity. Studies have mainly focused on large rivers in Kenya and Uganda. Impacts of habitat alteration by weir installation as a river management tool are lacking. This study aimed at comparing the limnological responses of Rivers Awach Seme (Kenya) and Nambale (Uganda), after weir installation. Data was collected monthly for si...
ABSTRACT Species of Aristida are a common component of rangelands of Northern Kenya. They provide high value pasture to livestock, especially during their young stage of growth. The ecological data relating to the distribution of Aristida species at a local scale is scanty. The objectives of this research were; to assess the distribution patterns of the three Aristida species occurring at Kifuko ranch during wet and dry seasons, to determine plant species associated with the three species of ...
ABSTRACT Recent studies have indicated that Bischofia javanica Blume (Euphorbiaceae), a tree species that was introduced in Kakamega forest as a restoration species in the early 1960s, is gradually recruiting and dominating its secondary and plantation forest stands. It is not clear whether this is a transitional succession process or a permanent takeover of the forest. The species has been reported to be invasive in other parts of the world such as Bonin forest and Oceanic Islands in West P...
ABSTRACT Trees provide both direct and indirect benefits to humans, who depend on them for their livelihoods. Forest ecosystems are vulnerable to over-utilization and exploitation due to the sensitivity of its complex and highly diverse ecosystem. The aim of the study was to determine the human impact on tree species diversity, abundance, plant population structure and uses of forest trees by local communities adjacent to Chemususu forest Reserve in Koibatek Sub-County, Baringo County. Ques...
ABSTRACT Populations of riverine fishes have been on a continuing decline since the early 1970s. This has been attributed to channeling, destruction of riparian vegetation, agricultural and industrial pollution, hydrologic alterations, introduction and invasion of exotic fish species, illegal methods of fishing such as the use of herbs and nets with small mesh sizes and other anthropogenic factors. Estimates from throughout the globe suggest that 75 to 95 percent of riverine habitats are deg...
ABSTRACT Riverine benthic communities play a crucial role in trophic relationships by providing major sources of energy to economically and ecologically important fishes. With the declining production of the Lake Victoria fisheries, the importance of surrounding rivers as sources of fish will continuously increase. There is therefore need to refocus the management of the riverine ecosystems in order to improve their fisheries production, particularly concerning their natural fish food product...
ABSRACT Tea is a major foreign exchange earner in Kenya and it accounts for about 24% of the total value of the domestic exports for the last 10 years. The sector employs 10% of Kenya’s population directly and indirectly, and contributes to infrastructural development which includes construction of schools and health facilities, rural access roads and rural industries. However, tea suffers frequent droughts with significant yield decline, often accompanied by plant deaths, a condition which...
ABSTRACT Sweet potato (Ipomoea batatas L.) is an important food crop consumed throughout Africa. However, sweet potato yields are greatly reduced by pests including plant parasitic nematodes. Management of nematodes in sweet potato fields in Kenya has mainly been through the use of nematicides and crop rotation which have limitations. The use of resistant sweet potato cultivars along with other low-cost organic amendments is the most economical, effective, and environmentally safe method of m...
TABLE OF CONTENTS DECLARATION................................................................................................................ i DEDICATION................................................................................................................... ii ACKNOWLEDGEMENT ............................................................................................... iii LIST OF TABLES ................................................................................................
ABSTRACT The demand for non-renewable fossil fuel has greatly increased in the last few years from 84 million barrels of fossil fuel per day in 1980’s to over 100 million barrels per day in 1990. To supplement this demand, research on alternative sources has been going on since 1960’s in different parts of the world. Among the alternative sources, the phytoplanktons have shown great promise due to their high oil yield in comparison to energy crops. In Kenya, despite the occurrence of high...
ABSTRACT Somalia is one of the most drought prone countries in Africa. Drought is the country’s costliest natural disaster. The impact of drought events on the economy, on people`s livelihoods and on lives has grown. Drought events usually develop gradually unnoticed, causing tremendous effects on both agriculture and environment. This study evaluated the spatio-temporal variations of drought occurrences in Somalia and its implication on forest cover. In this study, precipitation and temper...
ABSTRACT The study sought to determine abundance and species of nematode parasites of Oreochromis tilapicus and Clarias gariepinus in Lower Umguza Dam,in the Gwayi catchment area. Fish samples were collected from fishermen and sent to the laboratory for observation and identification using standard parasitological methods and identification guides. 479 nematode parasites were recovered from 160 fish belonging to 2 species; Oreochromis tilapicus and Clarias gariepinus. Four nematode genera; P...
Abstract The savanna biomes are characterised by a coexistence of two antagonist – woody plants and herbaceous plants in defiance of competing theories. Scientific efforts to understand this unique coexistence are still largely inconclusive; various theories have been proposed, but no unanimous theoretical framework exists to date. Among these theories, the root niche-partitioning model offers the most popular, yet the most controversially debated viewpoint. It argues that this coexistence...
Abstract The Iceland Basin in the N. Atlantic has attracted considerable recent attention because the spring bloom in this region acts as the most powerful biological carbon pump anywhere in the world oceans. Furthermore, the link between primary productivity and herbivory by the calanoid copepod, Ca/anus finmarchicus provides the trophic link between primary producers and the important commercial fishery for Atlantic Cod. However one result of ocean warming is that the distribution of t...