Assessment of the Invasiveness of Prosopis Juriflora that Cause Land Use Land Cover Changes: A Case Study of Baringo South Sub County.

Abstract

Prosopis Juriflora, a fast growing vegetation in the rangelands was introduced in Kenya in the 1970s to help in curbing the issues of desertification. The establishment of the species was in good faith but the spread was not controlled, hence its invasive nature was neglected. Consequently, the species has replaced most of the native species in the Kenyan rangelands and is dominating as the main land cover. To comprehend the impacts of the species, and provide the mitigation measures, it was necessary to carry out its time series assessment to derive its rate of colonization. GIS and Remote Sensing integration in this study acted as a mechanism of the study of the species’ rate of spread through satellite image analysis. Landsat multi-date imagery, ranging from 1985 to 2018 were downloaded from USGS website and classified into LULC classes namely: water, agricultural lands, open grasslands, prosopis canopies (prosopis dominated areas), and other-lands (bare-lands and built-up areas). Change detection was carried out to identify the area of change. In this study, only changes to prosopis were considered. The results indicated that the areas covered by prosopis covered 31% of the sub-county in 1985, 30% in 1995, 34% in 2005, and 42% in 2010 (This is a great increase, which indicates the invasiveness of the species). In 2018, the area of coverage of the species reduced to 31%. The study results also indicate a decline in agricultural lands, which is a threat to human life as it causes food shortages. In 1985, the agricultural land covered about 33% of the total land. This later reduced to 23% in 1995, and to 17% in 2005. A slight increase was noted in 2010 as it rose to 29%. However, the coverage reduced to 20% in 2018. The impacts of the species to livestock was also studied and it shows out of the sheep, goats, camels, and cattle, goats are the main victims of the species through poisoning. The sheep followed through intoxication. Cattle and camels were the least affected. Mitigation measures to the impacts were also suggested which included pruning and thinning, spraying with herbicides, uprooting, burning, and use of the species to generate electricity.