487 Records out of 22207 Records

A survey on knowledge, attitude and practice regarding cardiopulmonary resuscitation of pregnant women among Anesthesiology and Obstetrics registrars in Kenyatta National Hospital

Author: Kivungi, Patience Koka

Awarding University: University of Nairobi, Kenya

Level : MMed

Year: 2012

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Cardiopulmonary resuscitation--CPR/Physicians/Pregnancy/Women/Obstetrics/Gynecology/Kenyatta National Hospital, Nairobi, Kenya ;

Abstract:

Kenyatta National Hospital is the largest of the two main level 6 ( National Referral Hospital) health facilities in Kenya. It has one labour ward, with a bed capacity of twenty six. Though it is supposed to handle referrals mainly from public and sometimes private hospitals, it handles more walk in patients than referrals. Most of the times the hospital is not forewarned of the referrals so as to get prepared. Some of these mothers may require CPR (Cardiopulmonary Resuscitation) at some point during their management. Resuscitation of these mothers is done by a team consisting of obstetrics and gynaecology registrars (postgraduate students undertaking their masters degree) nurses and sometimes the anesthesiology registrars. Objective The objective of the study was to assess knowledge, attitude and practice of CPR of pregnant women among anesthesiology and obstetrics registrars. Methods It was a cross-sectional descriptive study was to assess knowledge, attitude and practice of CPR of pregnant women among anesthesiology and obstetrics gynaecology registrars. The target population was all anesthesiology registrars (n=26) and all Obstetrics Gynaecology (n=59). A pretested questionnaire was used to collect data which was then be analyzed using Statistical Package for Social scientists (version 11.0; SPSS, Chicago, IL) Results 78 (97.5%) felt training on resuscitation of pregnant woman was important. More than 51.2% of the registrars felt they were more than 50% knowledgeable. It was observed that resuscitation of pregnant women in KNH was done by obstetrics registrars covering the floor with the help of nurses and sometimes requested for resistance from the anesthesiology registrar on call. Majority of the anesthesiology registrars 20 (80%) felt that the team leader should be the Obstetrics registrar while majority of the Obstetrics registrars 51 (93%) felt that the anesthesiology registrar should be the team leader. 13 (15%) of the registrars felt that resuscitation was not necessary in some conditions. Majority (6) felt that resuscitation was not necessary in cases of prolonged cardiac arrest. Lack of equipment 62 (77.5%), lack of knowledge 52 (65%) and lack of team work 45 (55%), were graded as the major factors affecting CPR respectively. Anesthesiology registrars felt supine position was inappropriate for a pregnant woman and should instead be placed in the left lateral position to avoid aortocaval compression by the gravid uterus. More than half of the obstetrics registrars (58.2%) practice was in keeping with what the first responder should do according to the 2010 Algorithm on maternal cardiac arrest CPR. Anesthesiology registrars consider defibrillation to be an important part of resuscitation compared to the obstetrics registrars. 3 (5.5%) of obstetrics registrars would not defibrillate due to concerns about effect of the shock on the foetus. Despite the willingness to perform defibrillation on pregnant women by the registrars, very few of them actually adhere to the modified CPR protocol of removal of foetal monitors before defibrillation. 2 (3.6%) of the obstetrics registrars had ever performed a perimortem cis (Procedure of cesarean delivery concurrent with maternal C.P.R). 99% of the anesthesiology registrars were conversant with anatomical changes in the airway compared to obstetrics registrars 89.1%. Conclusion: Obstetrics and anaesthesiology registrars are more likely to encounter cardiac arrest in pregnancy. Although the incidence of this is small, this is not a reason for these cadres of doctors not to have knowledge on resuscitation of parturients and not to have the right attitude. Therefore these doctors should receive regular trainings on resuscitation focusing on parturients.

Field ecology of western flower thrips, Frankliniella occidentalis in french bean agroecosystems in Kenya

Author: Ounya, Johnson Nyasani

Awarding University: Leibniz Universitat Hannover, Germany

Level : PhD

Year: 2012

Holding Libraries: Kenya Agricultural Research Institute Headquarters Library ;

Subject Terms: Western Flower Thrips ; Beans ; Phaseolus vulgaris ; Frankliniella occidentalis ; Ecology ; Integrated pest management ; Cucurbita pepo ; Megalurothrips sjostedti ; Thrips ; Weeds ; Galinsoga parviflora ;

Abstract:

Western flower thrips (WFT), [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)], is one of the most important pests of French beans (Phaseolus vulgaris L.) in Kenya. Control of WFT is difficult because it has a wide host range, high reproduction rate, cryptic feeding habit, and ability to pupate in soil. Development of sustainable integrated pest management (lPM) strategies against the WFT requires a sound understanding of its field ecology in terms of colonisation pattern, seasonal abundance, and feeding and oviposition behaviour. An understanding of seasonal abundance of WFT is important in predicting when and where economically damaging populations may occur, understanding how crop damage occurs, planning efficient sampling protocols, and in developing effective management programmes that are area specific. Information on feeding and oviposition preference of WFT is a key research need for formulation of IPM strategies based on manipulation of cropping systems. However, the above named aspects have not been studied in details within French bean fields in Kenya. Therefore, the objectives of this study were to determine (1) seasonal abundance ofWFT and its natural enemies in French bean agroecosystems in Kenya, (2) the effect of intercrops on thrips species composition and population density on French beans, and (3) feeding and oviposition preference of WFT for crops and weeds encountered in French bean fields in Kenya. To determine the seasonal abundance of WFT and its natural enemies in field-grown French beans in Kenya, Field studies were conducted in two major French bean agroecological zones in Kenya from January 2009 to December 2009. French beans were sampled every two weeks for WFT and natural enemies. Colonisation of French beans with WFT in both small and large scale farms in high and mid altitude zones started at 2- and 3-leaf stage, respectively. There was an increase in the number of WFT from budding stage to podding/flowering stage. A decline in population density of WFT was at crop senescence. Two natural enemies of thrips, [Orius spp. (Hemiptera: Anthocoridae) and Ceranisus menes (Walker) (Hymenoptera: Eulophidae)], were recorded on French beans in all agroecological zones and their population grew in tandem with the population of WFT. Temperature and relative humidity were weakly correlated with the population density of WFT, while rainfall had a negative effect on the population density of WFT. Overall, the population density of WFT was least in the first growing season (January - April) which was in the long rains season. Higher population densities of WFT on French beans in all farm sizes and agroecological zones were recorded in the third growing season (September - December) which was in the short rains season. Results from this study suggest that seasonal abundance of WFT in the two agroecological zones is influenced by rainfall (depending on amount), phenological stage of French beans and surrounding host plants (where infestations on French beans arise from). To study thrips species composition and thrips population density on French beans planted as a sole crop and as an intercrop with either sunflower, Irish potato, or baby com, in different combinations field experiments were conducted in two seasons. French beans hosted four thrips species, Megalurothrips sjostedti (Trybom), Frankliniella schultzei (Trybom),F. occidentalis (Pergande), and Hydatothrips adolfifriderici (Kamy) in order of decreasing abundance. The main thrips species on Irish potato and sunflower was F. schultzei. Baby com hosted only Frankliniella williamsi (Hood) and Thrips pusillus (Bagnall). A mono crop of French bean hosted more thrips than a French bean intercrop mix. Plots with French bean alone had about 1.4 times higher yields compared to intercropped plots of French bean with sunflower and French bean with baby com. However, the percentage of pods that could get rejected on the market due to thrips d

Biology and ecology of the Coffee Berry fruit flies (Diptera : Tephritidae) at the University of Nairobi farm Kabete

Author: Mugambi, Ann Murugi

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 2012

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Biology ; Ecology ; Coffee ; Fruit flies ; Tephritidae ; University of Nairobi Farm Kabete ;

Abstract:

Past literature reveals that basic biological and ecological studies in Kenya on the coffee fruit flies were conducted nearly half a century ago. These studies were therefore initiated to update knowledge on the biology and ecology of the coffee berry fruit flies in view of changing fanning practices and the influences of climate change. The experiments were carried out at the University of Nairobi farm at Kabete Campus and also laboratory studies were conducted at Kabete laboratory. The specific objectives of this study were to compare the life cycles of coffee berry fruit flies, to determine the timing of the emergence activities of both larva and adults and to determine the ovipositional behaviour of coffee fruit flies on coffee berries at different stages of their maturation. The flies were identified by analysis of their morphological features under a light microscope. Three species of coffee fruit flies were identified (Ceratitis capitata Wied, Ceratitis rosa Karsch and Trirhithrum coffeae Bezzi) and their biology studied. Durations taken by the immature stages were studied and Friedman test used to test the hypothesis that there are no differences in the number of days required to complete development between the three species. The timing of emergence activities of Ceratitis capitata was studied by dividing mature larvae into two groups where one group was held indoors at a constant temperature of 20?C while the second group was studied out door under fluctuating temperature. To study ovipositional behaviour, five categories of berries namely; immature green, mature green, mature green- yellow, mature yellow- red and mature red berries were presented to gravid females. The ovipuntured berries were dissected under a microscope to examine for eggs. Statistical analysis by Analysis Of Variance (ANOVA) was used to test whether there were significant differences in the berry categories preferred for oviposition at p ~ 0.05 level. There were no significance differences in the number of days taken by eggs of the three species to complete development. The durations taken by larvae of the three species were different. There were significant differences at 0.05 level of significance in the number of days taken by larvae to complete development between the species ( Friedman test P < 0.05). The pupal duration for the three species was similar as shown by Friedman test (P > 0.05). There were no statistical differences between the species in the number of days taken by pupae to complete development. There was synchronization in the life cycles of the coffee berry fruit flies with ripe coffee berries. The emergence activities of flies were observed to occur in the early hours of the day when temperatures were low which reduces mortality rate of the emerging larvae and adults. The emergence pattern of fruit flies was influenced by diurnal periodicity. The flies preferred to oviposit on mature ripe coffee berries compared to green berries. No eggs were oviposited in the immature green berries while in other categories, there were varying amount of eggs. In conclusion, there was no much change in the biology and ecology in the three species of coffee fruit flies over the years. Most of the observations recorded in the life cycles were similar to those recorded by earlier authors. The sychronization of the life cycles of the three species of fruit flies provides sound ecological knowledge for planning effective management programmes. This makes control programmes cost effective and easy.

Towards an ecocentric perspective in Education

Author: Mwendwa, Cosmus Mutua

Awarding University: University of Nairobi, Kenya

Level : MEd

Year: 2011

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Education ; Ecology ;

Abstract:

The study makes phenomenological observation that the goals of education all over the world are just about man. Education, through its theory and practice, has helped develop very anthropocentric attitudes in man where he assumes that the other members, especially the biotic community, of the universal ecosystem are subordinate to him. That they are 'only instrumentally valuable, that is, valuable only to the extent they are means or instruments which serve human beings', (Collicott, 1984). The study appreciates that education is the only 'tool' that defines the destiny of man in the world and that the 'world and human beings do not exist apart from each other, they exist in constant interaction', (Freire, .1993). Due to man's anthropocentric attitudes, which are basically destructive in essence, the world has experienced profound and adverse effects which include but not limited to Climate Change, Ozone layer destruction, high rate of desertification, and all sorts of environmental degradation, among others. In the words of Paulo Freire in his Pedagogy of the Oppressed (1993), this is the tragic dilemma of the world which education must take into account. The study proposes that the theory and practice of education should be restructured in order to develop ecocentric attitudes; where man appreciates that other forms of life have intrinsic value in their very selves, and that man should relate to other members of the biotic community as 'equal' partners for mutual benefit. It calls for responsible interaction between man and the universal ecosystem. The study proposes, by giving some suggestions, that the goals of education, and by extension its theory and practice, should be restructured towards this end.

An assessment of the health, trade, economic and sustainability aspects of medicinal tree and shrub products (MTSPs) in Kenya

Author: McMullin, S

Awarding University: University College, Dublin, Ireland

Level : PhD

Year: 2011

Holding Libraries: Institute of Commonwealth Studies Library ;

Subject Terms: Folk medicine ; Health ; Medicinal plants ; Socioeconomic factors ; Ecology ; Trees ;

Abstract:

As demand continues for MTSPs, there has been increasing policy recognition and an impetus to promote the positive elements of the use and trade while limiting the negative aspects which threaten MTSP use, yet research and documentation of this sector have been scant in Kenya. This study assessed the economic and health importance of MTSPs to those involved in the practice, use and trade of these products. As a result of its findings, this study recommends research and policy action in the form of: 1) implementing a national policy for THM and MTSPs; 2) the role and involvement of the private sector in health care provision through THM and MTSPs; 3) a nation-wide utilisation study to collect data on patterns of use and preference for health; 4) public sensitisation and marketing campaigns to promote and support the safe and rational use of MTSPs; 5) a collaborative research agenda between Medicinal Doctors and Herbalists based on a specific disease treatment approach; 6) sustainable supply initiatives through assessing the potential for cultivation and priority setting for medicinal species cultivation; 7) support and organisation of trade actors and activities to improve trade chain activities and research efforts; and 8) further research in the trade to address the ecological sustainability of MTSP species, assessment of the volume and economic value of the trade and gender analysis of the trade.

Multiplication, conservation and genetic characterization of selected Macadamia germplasm in Kenya

Author: Gitonga, Lucy Njoki

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : PhD

Year: 2010

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Macadamia ; Macadamia tetraphylla ; Macadamia integrifolia ; Genetics ; Ecology ;

Abstract:

Macadamia tree is a low-input crop with high returns per unit area and hence has high potential in poverty reduction and wealth creation. However, the genetic diversity of Macadamia germ plasm in Kenya is not yet known. Multiplication rates are low and existing information on ecological adaptation is limited. Hence, the rate of breeding and expansion is not commensurate with existing potential and demand. Four main studies were carried out. The first study tested the response of 39 accessions to cuttings, grafting and tissue culture propagation methods, for multiplication and subsequent ex situ conservation of Macadamia germplasm. Shoot regeneration from M. integrifolia was achieved at a rate of eight shoots per explant, using single nodal explants cultured on half strength MS medium supplemented with 2.0 mgIL BAP, 1 mg/L IBA and 30 g/L sucrose and gelled will 9 gIL Biotec? agar (pH 5.7). With the development of rooting procedures, a complete protocol will be available for multiplication and in vitro ex situ conservation of Macadamia germplasm in Kenya. In the second study, analysis of 39 GPS data points using ArcView GIS 3.3 mapped the accessions on to six major agro-ecological zones; UM 1, UM2, UM3, UM4, LHI and UHO. All accessions except five were mapped on Nitosols. Distribution of Macadamia in relation to soils was established, and coupled with the information on agro-ecological zoning, breeders have the opportunity for selection and breeding to expand Macadamia acreages. In the third study, the accessions were assessed for morphological diversity based on a set of standard qualitative and quantitative characters of leaf, fruit and xxi flower. Phylogenetic analysis based on UPGMA for leaf traits using XLSTA T (2009) grouped the accessions into three major clusters corresponding to M tetraphylla, M integrilfolia, and their hybrids. The highest morphological diversity, 81.57, was between M tetraphylla and M integrilfolia. After principle component analysis, PC 1 was effective in grouping the accessions in to three clusters consistent with phylogenetic analysis. This indicates that leaf traits in Macadamia can be used fro quick classification by breeders in the field. The fourth study analyzed the genetic diversity of26 out of the 39 accessions using six AFLP primer combinations. The 26 accessions were from five populations Bob Harries, Thika, Kirinyaga, Embu, and Meru. Genetic diversity analysis using GenA lEx version 6.2 revealed that Bob Harries was the most genetically diverse with the highest percentage of polymorphic loci of 80% and highest mean heterozygosity, H,ofO.295 while Thika population had the least diversity of 67.3 % of polymorphic loci and He of 0.224. The Embu population was distantly related to all the population and it contained a private allele, making it unique and worth for breeding and conservation. Phylogenetic analysis using TFPGA distributed the 26 accessions in to four clusters and exhibited a highly hybridized germplasm. The AFLP markers were found to be very effective in genetic characterization of Macadamia and provided sufficient information that can immediately be used by breeders for effective sampling for selection, hybrid variety development and conservation. This study reveals existence of high genetic diversity in Macadamia germ plasm in Kenya that is widely adapted. The germplasm should be vegetatively propagated by grafting for ex situ conservation before finalization of a tissue culture protocol, for breeding purposes.

Schistosoma mansoni and Biomphalaria snails in Lake Victoria : distribution, genetics and ecological dynamics

Author: Standley, C J

Awarding University: University of Nottingham, England

Level : PhD

Year: 2010

Holding Libraries: Institute of Commonwealth Studies Library ;

Subject Terms: Schistsosoma mansoni/Schistosomiasis/Biomphalaria/Mollusks/Lake Victoria, Kenya/Genetics/Ecology/Chimpanzees/Epidemiology/ ;

Abstract:

Lake Victoria is a hotspot for intestinal schistosomiasis: this thesis demonstrated the endemicity but also the heterogeneities of prevalence of intestinal schistosomiasis in schools in Uganda, Kenya and Tanzania. Traditional stool-based microscopy was compared to new, rapid diagnostic tests (RDTs): RDTs were found to be sensitive but variable across the region; one explanation is the high genetic diversity of S. mansoni around the lake, examined using molecular markers. Despite this high diversity, populations showed low geographical structuring, perhaps due to human migration or strong compatibility to local Biomphalaria. These snails are also heterogeneously distributed and environmental correlates were tested using Bayesian spatial analysis. A key facet of this research was the taxonomic analysis of the two Biomphalaria ?species? in Lake Victoria; molecular and morphological tests demonstrated they are ecophenotypes of one, morphologically and molecularly diverse, species. Indeed, genetic diversity in Biomphalaria from Lake Victoria was high, as with S. mansoni, but tests demonstrated clear geographical structuring, possible due to the stability of the lake environment. Micro-scale analysis allowed for further examination of environmental variables but also a detailed investigation into the presence of S. mansoni in semi-captive chimpanzees on Ngamba Island; the chimpanzees were shown conclusively to be infected, and molecular analysis revealed cross-over with local human genotypes of the parasite, suggesting anthropozoonotic transmission. The data throughout the thesis point to the importance of biodiversity at different stages of schistosomiasis transmission. This is a topic that requires further investigation. Overall, the results add to our understanding of the dynamics of a globally important neglected tropical disease, in a highly endemic setting and as such, will contribute to on-going research and disease control efforts.

Microbial diversity of Lake Elementaita, Kenya

Author: Kachiuru, Romano Mwirichia

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : PhD

Year: 2009

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Ecology/Microbiology/Lake Elementaita/ ;

Abstract:

The major goal of microbial ecology is to understand microbial diversity in natural habitats their interaction with one another and with their habitat. The soda lakes are highly productive environments and the soda lakes of the East African Rift valley have been shown to support a dense and diverse population of aerobic, organotrophic, halophilic, alkaliphilic and alkalitolerant representatives of major bacterial and archaeal phyla. The isolation and characterization of organisms belonging to widespread but previously uncultivated groups of organisms can provide insights into the roles and functions of these organisms in their natural settings and assist in the formulation of hypotheses about metabolic interactions between microorganisms and their natural environment. Several studies have been carried out to document the microbial diversity of the Kenyan soda lakes by other researchers. However no comprehensive study has been done in Lake Elmenteita. The aim of this study was to assess the microbial diversity of Lake Elmenteita using both culture independent and culture dependent techniques. The application of both techniques was expected to provide new insights into the microbial diversity of the Lake as well as possible roles played by each group within the soda lake environment. Application of molecular tools to study microbial ecology has widened our approximation of diversity in the environments. Clone Libraries were constructed from PeR amplicons from total environmental DNA. Primers specific for Bacteria and Archaea respectively were used. Partial sequences were generated for both the clones and the isolates. The relatedness of the Lake Elmenteita bacterial rRNA sequences to known rRNA gene sequences was determined by BLAST analysis and by alignment to the sequences on the ARB database (Release, 1994). Clones possessed a higher similarity to other environmental clones than to cultured microorganisms. A total of 655 clone sequences were sequenced. Of these 525 (80.15%) sequences were related to uncultured members of the Domain Bacteria. This indicates that a large proportion of deep phylogenetic groups are represented in the clone libraries. Sixteen percent of the clones had similarity values below 90% to both cultured and uncultured microorganisms. Forty three percent of the clones had similarity values between 90-95% as compared to 34.35% that had values between 96-98%. Only a mere 6.87% had values between 99-100%. However a number of factors including relatively low cell numbers of large organisms and a variable number of rRNA operons among organisms, as well as extraction and PCR bias, may lead to under-representation of phylotypes relative to their in situ abundance. Cultured isolates are still very important in developing our understanding of bacterial physiology. genetics, and ecology. Isolation was done using both nutrient rich and nutrient poor media. A polyphasic approach was employed in the identification ofthe various strains. The majority of the isolates (36.75%) belonged to the genus Halomonas while 31.35% belonged to the Genus Bacillus. More than half of the isolates (59.45%) belonged to the Gammaproteobacteria. An overlap between the clone library and the isolates was observed in the Order Bacillales and the Actinobacteria only. In this study novel isolates related to Marinospirillum, Idiomarina, Streptomyces, Nocardia, Marinilactibacillus, Amphibacillus and Vibrio were recovered. A polyphasic approach to characterization showed they represented novel taxa. The study showed that the application of both culture dependent and culture independent methods gives a better picture of diversity in the environment. It can be concluded the soda lakes harbour novel uncultured groups of microorganisms and most of them are of biotechnological potential. Future work should focus on Archaeal diversity as well as the uncultured groups of bacteria.

Impact of land-use change on ecology, resource productivity and adaptive strategies of smallholder agro-pastoralists in Machakos-Makueni districts, Kenya

Author: Kirwa, Everlyne Cheptarus

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 2009

Holding Libraries: University of Nairobi Upper Kabete Library ;

Subject Terms: Machakos District/Makueni District/Ecology/Land/Land use/Land use change/ ;

Abstract:

Semi arid areas in Kenya are experiencing socio-economic processes leading to land subdivisions and subsequent changes in land-use patterns. Changes in land-use negatively affect the ecological resource base through replacement of native plant species, loss of wildlife habitats and reduced quality and quantity of water. A study was therefore carried out to analyze the impact of land subdivision and shifts from commercial ranches to smallholder agro-pastoral production systems on the ecological resource base, resource productivity and agro-pastoral adaptive strategies in Machakos and Makueni Districts. Ecological studies involved sampling for vegetation and soil attributes in 2 nonsubdivided cooperative ranches and 3 subdivided ranches with transects cutting across smallholder farms (SMFs). Vegetation and soil samples were analysed for vegetation attributes and physical and chemical properties, respectively, using standard methods. Household survey involving 90 households was also carried out to determine impact of the land-use change and land subdivision on resource productivity and characterize the agro-pastoral adaptive strategies given the shifts. Data for household output and income was analysed using log-log regression models. The SMFs had significantly higher (p:::S0.05) frequency and biomass production for annuals grass species while the ranches had higher (p:S0.05) percent ground cover and biomass production for perennial grasses, forbs and litter. This indicated that SMFs were more degraded than the ranches probably due to the attendant continuous cultivation and overgrazing. Significant decline (p:S0.05) in important soil chemical properties was recorded in the SMFs, particularly nitrogen, phosphorus, magnesium, manganese and sodium levels. Soil Organic carbon (SOC) significantly reduced (p:S0.05) with increasing period of subdivision and settlement. There was a significant (p:sD.05) and positive relationship between land size and household output, suggesting that continued fragmentation of land in the rangelands could cause significant decline in household output. In addition, the results show that households in the study were operating below the optimal level of production and would more than double their output if they doubled their inputs including land. Trends in household returns indicated increased returns with increase in land size. In spite of land subdivision, early planting, use of drought resistant crops, predation control and feed conservation were some of the important agro-pastoral adaptive strategies in' the study area. But, unreliable rainfall, access to land and water, acquisition of skills, shortage of pasture and predation were the main factors influencing shifts in the adaptive strategies. Fragmentation of ranches and change in land-use to smallholder agro-pastoral production systems in the area should be done in tandem with adoption of technologies that will allow exploitation of land-based resources without compromising on the ecological integrity in the long run. Therefore, there is need to determine land use and size thresholds that will not affect land productivity to meet minimum household requirements of the agro-pastoral system. Furthermore, due to the trends in land degradation in the SMFs, there is urgent need for development of appropriate technologies that would contribute to reversing the degradation trends and increase land productivity in the area. v

Effects of burn size and burn patterns on the aboveground net primary production on savanna ecosystem, Laikipia Kenya

Author: Kimathi, Isaac K

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 2009

Holding Libraries: University of Nairobi Upper Kabete Library ;

Subject Terms: Laikipia District/Burns/Fires/Ecology/' ;

Abstract:

This study investigated the separate and combined influences of fire and herbivores on herbaceous layer primary production in burn treatments of various scales and patchiness. The study was conducted in savanna ecosystem of central Laikipia in Kenya. The treatments included a nine hectare and one hectare burn, each size had two continuous burns (CB), two patchy burns (PB) and one control which was unbumt. Standing biomass, primary productivity and herbage utilisation in each treatment was measured from April to August 2005 following rains after bum using movable cage method. The results showed a significant difference (p<0.05) for net primary production and standing biomass between burned and unburned treatments. Burn treatment, recorded the highest net primary production (418.6 gm2) which was four times more than that recorded in the unburn treatment while mean standing biomass for burn treatment (54.5 gm2) was three times lower that recorded in unburned (214.2 gm2) treatment. Buming had an effect on both standing biomass and net primary production. Burn treatment resulted in a higher net primary production and lower standing biomass (due to increased intensity of grazing herbivores.) Daily herbage utilization was high in the burn which could be one of the factors contributing to the low standing biomass and high net primary production compared to unburnt treatments. Large burn treatments had a lower standing biomass where else small burn treatments had more standing biomass. The reason might have been that large burns were highly utilized to small burns. They might also have been preferred by grazers as predators 'watch spots' in case a predator approaches it could be spotted from far. The standing biomass obtained in this study in burn pastures suggest there is a high preference to grazing in the burn thus keeping the herbaceous layer shorter. Burn treatments attracted grazers and thus reducing the standing biomass (grass size), this could be due to the flush and nutritious regrowth after the burn. Utilization was highest in the larger burn (9 hectare) treatment which differed significantly (p>0.05) with other treatments except for the smaller burn treatment. Utilization in 1 hectare burn was high but not significantly difference to any of the other smaller treatments. Larger burn treatments (9 hectares) contributed 71.0% and 59.4%( primary production measures) while smaller burn treatment (1 hectare) contributed 29% and 40.6% of total net primary productivity in the burn, burn and unburn (unburn and control) treatments respectively. In spite of high net primary production, larger burn treatments recorded herbage removal of 30.1 % while smaller burn treatment recorded 22.8% of total burn and unburn herbage removal. On the other hand, 52.9% of all treatment net primary production was utilized in the burns compared to 47.1 % removal in unburn treatments. The mean daily aboveground net primary production was 18.0?4.6 gm2 and 10.7?2.8gm2 in treatments patchy Burn and continuous Burn respectively with no significant difference between them. Utilization and standing herbage biomass was relatively higher in treatment Patch Burn than treatment continuous Burn. Treatment continuous Burn had a relatively low standing biomass to treatments patchy Burn irrespective of burn size. However larger burns for both continuous Burn and patchy Burn had lower standing biomass relative to the smaller burns but significantly higher production. Vll