Exploring the diversity and distribution of trees outside forests along the urban-rural gradient of Murang’a municipality, Kenya

Urban expansion leads to landscape alteration that significantly affects vegetation diversity and distribution. This paper examines the distribution of trees outside forested areas (TOF) along the urban-rural gradients of Murang’a Municipality, Kenya. A stratified simple random sampling method was used to obtain data from 72 points along the gradient, resulting in a density of 0.62 points/km2. Biodiversity R software was used to analyse TOF abundance and species diversity data, assess the correlations between proximity to urban areas and these TOF metrics, and assess the distribution of the metrics along the gradient. Findings indicate that TOF species diversity remains stable across the urban-rural gradient, thus challenging the assumption that biodiversity declines with urbanisation. Exotic species’ abundance increased with distance from urban centres, which implies that rural areas may still face other forms of disturbance that favour certain species. However, indigenous species show minor fluctuations along the gradient due to socioeconomic benefits or interactions with exotic species that are resilient to varying disturbances. The paper provides insights into the complex relationships between human disturbances and biodiversity, suggesting a need to re-evaluate the Intermediate Disturbance Hypothesis or develop a new model to accurately represent dynamics in urban-rural ecosystems.