Impact of Abandoned Maasai Bomas on the Spread of Urtica massaica and Plant Species Diversity in the Ngorongoro Conservation Area, Tanzania

Abandoned pastoral settlements can create disturbed and nutrient-enriched microsites that favor the dominance of native expansive plant species. Yet limited empirical evidence exists on how abandoned Maasai bomas influence the spread of Urtica massaica and associated plant community changes in the Ngorongoro Conservation Area, a UNESCO World Heritage Site in Tanzania. This study assessed the influence of abandoned bomas on plant species abundance, richness, diversity, soil seedbank status, and the spatial distribution of U. massaica. A multistage stratified random sampling design was used, whereby Ngorongoro and Nainokanoka zones were selected from the designated management zones of the conservation area. Vegetation data, soil samples, and geographic coordinates of abandoned bomas were collected from abandoned boma sites and adjacent control sites. Plant species abundance, richness, and diversity were compared between abandoned bomas and control sites after testing data normality using the Shapiro–Wilk test. Independent-sample t-tests were used for normally distributed data, while Wilcoxon rank-sum tests were used for non-normally distributed data. Spatial distribution of U. massaica was assessed using GIS-based heatmap and kernel density estimation. Results showed that native plant species abundance was significantly higher in control sites than in abandoned bomas. Plant species richness and diversity also differed significantly between sites in both Ngorongoro and Nainokanoka, with control sites supporting higher richness and diversity. However, soil seedbank results showed no significant differences in species richness and diversity between soils collected from abandoned bomas and control sites, although slightly higher values were observed in control soils. Spatial analysis revealed that U. massaica hotspots were concentrated mainly in highland areas with high densities of abandoned bomas. These findings suggest that abandoned bomas may act as focal points for U. massaica establishment and dominance, reducing aboveground plant diversity while retaining some potential for natural regeneration through the soil seedbank. Management interventions should prioritize abandoned bomas as key sites for controlling U. massaica spread and supporting vegetation recovery in the Ngorongoro Conservation Area.