Natural Resources Management

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Browsing Natural Resources Management by Subject "Karatina University"

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  • Publication
    Publication
    Effects of Vegetation Cover and Topographic Positioning on Soil Organic Carbon, Soil Aggregates and Water Infiltration Rates in Laikipia Grasslands, Kenya
    (Research Gate, 2020-11) Mutuku, Daisy Muthike
    Soil degradation activities in semi-arid grasslands have contributed to loss of vegetation cover, removal of surface soil, reduced soil organic matter and instability of soil aggregates thus reducing water infiltration rates in the soil. Soil losses are partly influenced by human-induced practices such as grazing, bush clearing and cultivation. The aim of this study was to investigate the influence of vegetation cover types and topographic positioning on soil organic matter, aggregate stability and water infiltration rates. The study was carried out in two semi-arid grasslands: Mpala and Ilmotiok ranches in Laikipia County, Kenya. Three vegetation cover types; (Tree, Grass and Bare gounds) and four topographic positions (Hillslope, Headwater, Riparian, and Plateau) were evaluated. A reconnaissance survey was done to demarcate a sampling grid of 4*4 km2 area in each site. A stratified sampling design was then used to demarcate four transect plots (Riparian-RIP, Plateau-PLA, Headwater-HW and Hillslope-HS). Within the four plots, three subplots comprising of Grass fields, Bare grounds and Tree fields were identified. Soils were sampled within a 5 m radius at 0-10, 10-20, 20-30, 30-40, 40-50 cm depths for laboratory determination of organic carbon, bulk density and water stable aggregate during the dry season of May to August 2016. Organic matter was estimated from the organic carbon content by multiplying percent organic carbon with a factor of 1.724. Data was subjected to two-way analysis of variance using SAS statistical software. A multiple comparison test (T-test) using LSD at P=0.05 was done to separate the means of various soil parameters and to isolate the significant differences between each of the vegetation cover types, topographic zones and soil depths in both sites. All statistical tests were considered significant at the level of P < 0.05. The study revealed that soil organic carbon and organic matter (SOM) differed significantly at (P=0.0001) among the vegetation cover types, topographic zones and soil depth for both sites. Soil aggregate stability varied significantly between topographic zones (P=0.0124) but not between the vegetation cover types and soil depth in Ilmotiok site. Mpala site showed a significant difference in aggregate stability between the topographic zones (P=0.0152). However, no significant difference was observed in variation of aggregate stability between the vegetation cover types and soil depth (P=0.8998; P=0.8284), respectively. In Ilmotiok site, the highest infiltration rate was recorded in the Tree covered fields (73.3 mm/hr) and decreased in Grass fields and Bare grounds at 25 and 17 mm/hr, respectively. The Headwater zones had the highest infiltration rates (73.3 mm/hr) while the lowest infiltration rates were (0 mm/hr) in the Hillslope zones. The infiltration rates in Mpala site were highest in Bare grounds (37.8 mm/hr) and lowest in Tree fields with 5.7 mm/hr. The Headwater zones had the highest infiltration rates followed by Hillslope zones with (8.9 mm/hr) while the Riparian zones had the lowest infiltration rates (0.00 mm/hr).
  • Publication
    Publication
    Sustainable Utilization of Wetlands Resources in Selected Areas of Nyamira County, Kenya
    (Research journali’s Journal of Geography, 2015-01) Huho, Julius M.; Angawa, Francis O.; Nyaboga, John Oganda
    Researches on wetland utilization in Kenya focus more on wetlands located in the ASALs and Lowland areas giving less emphasis to those in high agricultural potential highland areas. This paper examined the utilization of Sironga and Nyabomite wetlands resources in the high potential agricultural areas of Nyamira County. The specific objective established the resources and their uses. Purposive sampling was used in selecting study areas and key informants. Simple random sampling was used in selecting household heads. Data was obtained through the administration of 126 questionnaires of which 115 was used for analysis. Quantitative data was analyzed using descriptive statistics. Data was presented using statistical tables, percentages and photographs. The common wetland resources utilization practices in the area are brick making activities and crop production. Traditionally, the wetlands provided place for conducting rituals and ceremonies. The following recommendations ought to be prioritized: identification of key stakeholders and assessment of their interests; emphasis on afforestation of the wetlands with trees that are friendly to the environment and adoption of alternative sources of livelihoods. The recommendations of this paper are useful in the sustainable utilization of wetland resources in Nyamira County and other high agricultural potential areas.Keywords: Biodiversity, conservation, livelihoods, utilization, wetland resources
  • Publication
    Publication
    The Role of Selected Environmental Factors on the Regeneration of (Ocotea usambarensis ) in Mount Kenya Forest, Kenya
    (International Journal of Agriculture, Environment and Bioresearch, 2018-08) E., Githae; G. M, Nduru; A. M., Magana; J. N, Rithaa
    Despites the propagation efforts, density of Ocotea usambarensis has continued to diminish in the southern slopes of Mount Kenya. The species which is native in the montane forest is seldom on farm and found as remnant species. The concerns on the role of environmental factors and how they influence regeneration of Ocotea usambarensis have been sidelined resulting to lack of adequate information that would be required for modeling how to reestablish Ocotea usambarensis. This study therefore examined the role of Rainfall, Humidity, Temperature, wind speed and soil characteristics on regeneration of Ocotea usambarensis. The study was conducted in the southern slopes of Mount Kenya forest. Data on environmental factors, regeneration status and species diversity were analyzed using regression, Pearson Correlation, Shannon- Wiener (H ) Index and Simpson (D) Index. The regeneration status was “J” shaped with mature trees more than regenerants. The relationship was strong (R2 = 78%) between humidity and rainfall (P < 0.05) while for temperature and wind speed were insignificant. The correlation between soil compositions varied significantly (P< 0.05). The soil pH positively correlated with soil nutrients while Cation exchanges capacity negatively correlated with potassium and silicon. It was observed that Diospyros abyssinica was growing in close association with O. usambarensis playing the role of nurse species. With the absence of seedlings in most of the sites and the limiting environmental factors, promotion of vegetative propagation and enrichment planting would enhance conservation and restoration of the species in Mt. Kenya forest. The high levels of soil nutrients and Cation exchange capacity in forest soils indicated the need to maintain them high on farm for optimal growth rate. Enhancing optimal environmental conditions for growth would enhance conservation and restoration of the Ocotea usambarensis