Assessing the impacts of land use changes on tree occurrence and diversity :

Abstract

This research examines the profound influence of land use and land cover changes on tree occurrence and diversity within the Nalwenkomba Wetland Catchment in Uganda's Kamuli District. Employing a mixed-methods approach encompassing remote sensing, vegetation surveys, and socioeconomic analysis, the study scrutinized the years 2013 to 2021. The findings revealed that among the catchment's 216.25 square kilometers, 20.83% experienced degradation, while 17.09% showed improvement, and 62.08% remained stable based on land condition assessments. The degraded land witnessed substantial alterations due to deforestation (for timber, charcoal, and firewood), agricultural expansion (notably sugarcane farming), and artificial urbanization activities like construction and sand mining, resulting in an annual degradation of 563.86 hectares. This degradation has negatively impacted tree occurrence and diversity, influencing habitat structure and environmental conditions within the catchment, home to over 26 tree species. Notably, transitions towards agroforestry systems, particularly cropland to agroforestry, emerged as potential solutions to enhance tree occurrence and species diversity. These changes not only boosted tree numbers and species but also improved soil fertility, water retention, and overall ecosystem services. Community involvement emerged as pivotal, with 84% of the sampled households actively engaged in conservation efforts, underscoring the significance of local knowledge and participation in sustainable land management practices. Conversely, the conversion of land from agroforestry to specific croplands, especially sugarcane fields, significantly diminished tree occurrence and diversity. This study significantly augments existing knowledge by offering detailed insights into how land use changes impact tree occurrence and diversity within wetland catchments. It emphasizes the importance of adopting sustainable practices, particularly agroforestry, and highlights the indispensable role of community engagement in preserving tree diversity amidst evolving land use patterns. Ultimately, it underscores the need for informed land management strategies to maintain and enhance tree diversity, crucial for the resilience and functionality of ecosystems within these delicate environments. Keywords: Land use changes, Tree occurrence, Tree diversity, Wetland catchment, Sustainable land management, Agroforestry.