Background and Aims: The rising global population has increased land demand due to the increased need for agricultural and settlement spaces. Land ownership security tremendously impacts environmental sustainability because it influences ecological decisions. Kenya's land ownership and land use changes nexus has not received sufficient attention. Consequently, we explored this research gap in Mwatate Sub County, Taita County, Kenya. Methods: A sample size of 301 households was selected using stratified proportionate and simple random sampling techniques. A cross-sectional survey research design was used, while data was collected using semi-structured questionnaires. The Neo-Malthusian theory was adopted as a theoretical framework. Results: Results revealed that most (85.6%) households had insecure land ownership rights. Most (64.1%) households inherited land and had no Title deeds. Accordingly, findings reveal unsustainable land use practices, including deforestation, tree logging, high fuelwood use, bush clearance for human settlement and cultivation, poor farming methods, and overreliance on agriculture for livelihood. Using a 95% confidence level, Chi-square tests revealed a significant relationship between agricultural land use changes and land ownership security. Our findings concluded that insecure land ownership influenced agricultural expansion, deforestation, clearing of land for human settlement, and the type of farming techniques adopted by farmers. Implications for Conservation: Taita Taveta is a vital biodiversity hotspot that continues to be degraded by human activities. The correlation between land ownership and land use changes established by our study confirms the impending land degradation and threat to biodiversity loss. This is coupled with the concern that approximately 62% and 11% of the county are under a National Park and sisal estates, respectively, implying a growing threat to biodiversity loss and the need for enhanced conservation efforts in the area. This calls for the need to address the constant land issues in the area to incentivize sustainable land use practices.
