Influence ofAnthropogenicdisturbance on ecosystem health status of River Sironko catchment, on the slopes of Mount Elgon, Uganda

Abstract

Habitat quality and resident macroinvertebrates were used to assess the influence of different anthropogenic disturbances (land uses) on ecosystem health status of River Sironko catchment. The study was carried out at different land use sites (natural forest, pastureland, planted forest, mixed agriculture, banana plantation, urban and sugarcane plantation) from November 2019 to April 2020 during wet and dry seasons. A total of 3,944 macroinvertebrate individuals were identified consisting of 30 families with different levels of tolerance to pollution: 8 were sensitive to pollution and 10 were tolerant while the majority 12 were moderately sensitive. Based on SASS-ASPT, the overall ecosystem health ranged from fair to good and natural. Integrated Habitat Quality Score (IHAS) ranged between 46±0.82percent in urban site to 65±0.82% in forested sites. There was a statistical significant difference in SASS among natural and planted forest, mixed agriculture, banana plantation and sugarcane agriculture, Makuyu urban and sand mining (ANOVA at p ≤ 0.05). There was a highly significant positive correlation between SASS (macroinvertebrates) scores and riparian vegetation (r = 0.77, p≤0.01), stream condition (r=0.59, p≤0.01) and IHAS totals(r=0.46, p≤0.01) (habitat). Based on this finding, we concluded that land use influences physico-chemical habitat quality which in turn influences macroinvertebrate assemblage and therefore the ecosystem health status