The Influence of Anthropogenic Activities on Forest Cover Change in Mbiwe Forest Reserve, Chunya District, Tanzania

Abstract

Unsustainable land uses resulting from increased anthropogenic activities have led to land use cover change (LUCC), undermining forest resilience by altering ecosystem functions and biodiversity values. This study quantified anthropogenic disturbances and their influence on forest cover change in Mbiwe Forest Reserve, Tanzania, from 2013 to 2024. Dry-season Landsat 8 (2013, 2018) and Landsat 9 (2024) imagery were collected and processed in Google Earth Engine, median composited and classified into closed woodland, open woodland, mining and other land cover using a Random Forest Model, achieving overall accuracies of 82%, 85% and 80% and Kappa values of 0.75, 0.80 and 0.73 for 2013, 2018 and 2024 respectively. Post-classification change detection in QGIS produced net area changes and annual rates of change. Ground-truth data were collected from 50 systematically and purposively established rectangular plots (40 disturbed, 10 undisturbed), where human disturbance was observed, scored, and recorded. Descriptive statistics quantified each activity’s share of total disturbance, and Kruskal–Wallis tests confirmed significant differences between disturbed and undisturbed plots. The study revealed that the open woodland declined from 17,441.5 ha (48.1 %) to 7,812.6 ha (21.5%), closed woodland decreased from 4,642.9 ha (12.8%) to 3,902.5 ha (10.8%), mining expanded to 7,709.0 ha (21.3%) by 2018 before easing to 6,629.5 ha (18.3%), and other land cover rose steadily to 17,921.7 ha (49.4%). Annual open woodland loss rates were –12.6% (2013–2018) and –2.9% (2018–2024), resulting from mining activities, illegal logging, charcoal production, forest fires, agriculture, grazing, and settlement. The study recommends intensifying protection of buffer zones, implementing targeted tree planting of native species to act as a shock absorber, and enforcing land use regulations to curb illegal artisanal mining, logging, and agricultural activities.