IMPACTS OF VACHELIA REFICIENS AND PROSOPIS JULIFLORA ON SOCIO-ECONOMIC ACTIVITIES, ENVIRONMENT AND INTERVENTIONS IN SAMBURU EAST SUB -COUNTY, KENYA

Abstract

Invasive species have been known to have enormous environmental and economic costs. In Samburu East Sub-County of Kenya, two common invasive species in the region Vachelia reficiens and Prosopis juliflora have been observed to have spread widely. The resident community and the government are concerned about the extent of the spread and establishment of the species in the area. To address these concerns, the study aimed at analyzing their impacts on socio-economic activities, on the environment and the spatial variations of impacts, and effectiveness of interventions in place. To obtain quantitative and qualitative data, sequential explanatory mixedmethod study design was used. To achieve this, multistage clustered random sampling at each stage of the administrative units was used to obtain sampling design frame. Systematic sampling method was employed to get data from the household heads in each of the Ultimate Sampling Units. Structured research instruments were used to obtain data from 138 household heads, 10 Key Informants who were knowledgeable on the subject of the research, and 3 Focus Group Discussions comprising of mature persons of both gender knowledgeable on invasive species. Household heads questionnaire were pre-tested outside the study area. Kaiser-Meyer-Olkin index of 0.847 and Cronbach alpha reliability coefficient of 0.891 confirmed questionnaire validity and reliability respectively. Observation and photography employed to confirm species impacts and the physical environment. Data from household heads was analyzed using descriptive and inferential statistics while that of Key Informants and Focused Group Discussions was analyzed descriptively based on the dominant themes and narratives. To assess species impact magnitudes and efficacy of interventions measures, a perception count of a five-point Likert scale was used. The results show that impact of Vachelia reficiens were higher in magnitude than of Prosopis juliflora and the effective method of interventions was prescribed cutting. The results were statistically significant based on the chi square test analysis at p < 0.05. It was concluded that the two plant species have statistically significant negative impacts on the socio-economic activities; governance, livestock keeping, income and expenditure systems, local transport services and natural resource based conflicts, and environmental components; water availability, wildlife, land productivity, grasslands and natural regeneration of indiginous plants, and impacts differ over space. The variance between the impacts of the two plant species was statistically significant. The study recommends capacity building of communities and development of a management plan to guide on sustainable eradication of invasive plants and formulation of a policy. The policy to provide incentives, promote research, education, resource mobilization and allocations for the management of the invasive plants in the sub-county. Implementation of the recommendations will enhance environmental sustainability in the sub-county. It is expected that information from the study is useful to the Kenya government, Samburu County Government, development partners, resident community, rangeland actors, policy and decision makers in understanding, prioritizing and directing strategies, plans and actions on the management of the invasive species to safeguard environment and socio-economic activities for sustainable development in the sub-county.