The effect of refugee population influx on plant diversity of Bugoma forest, Uganda

Abstract

Refugee population is one of the causes of land and environmental degradation in refugee hosting countries. However, the relationship between forest plant diversity and refugee population influx is not well documented. This study assessed the effect of refugee population influx in Kyangwali Refugee settlement on plant diversity of Bugoma Forest in Uganda. Sentinel 2 imagery data for the study area for 2016, 2018, 2020 were used for vegetation cover and land use change analysis using QGIS 3.12 and 296 households were randomly surveyed for socio economic data. A total of 1,091 plant counts were recorded in 18 plots for computation of plant species diversity and richness. Simpsons diversity for tree species ranged between 0.4562 to 0.9583 for Kyangwali block accessed by refugees and 0.7873 to 0.9979 for Muhangaizima block accessed by host community . A higher Shannon weiner index of 2.4836 was recorded in Muhangaizima block compared to 2.0106 for Kyangwali block. Grasslands experienced the biggest vegetation cover loss (11.09%) followed by woodland (2.73%) and the tropical high forest (0.85%) while subsistence farming and built up land uses increased by 11.8% and 2.09% respectively for the study period 2016 to 2020 that coincides with the biggest refugee population influx in Kyangwali refugee settlement. Whereas refugees and host community accessed forest resources mainly fire wood, charcoal and building materials from Bugoma forest for cooking energy, livelihood and building construction, the dependence on Bugoma forest as a source of these resources was higher for refugee households than the host community. Pearson’s correlation coefficient revealed a positive relationship between the plant diversity and quantity of firewood used by the refugee households (r=0.047, p=0.004, n=296) and frequency of collecting forest resources (r=0.011, p=0.002, n=296). Therefore, the refugee population influx in Kyangwali refugee settlement to a large extent contributed to decrease in plant diversity of Bugoma forest. However, other underlying factors affecting plant diversity in Bugoma forest require further studies