Persistence and fragmentation of Dry Thorn and Than-Dahat Forests in the Central Myanmar Dry Zone over the last 25 years

The Central Myanmar Dry Zone (CDZ) contains some of Myanmar's least studied dryland ecosystems, including Dry Thorn Forest (DTF) and Than-Dahat Forest (TDF), which support unique biodiversity and ecosystem functions. This study assessed long-term changes in the extent, fragmentation, and disturbance of these vegetation types using multi-temporal remote sensing and spatial analysis. Landsat imagery from 2000, 2008, 2016, and 2024 was classified into 12 land-cover classes using a Random Forest classifier, achieving overall accuracies of 91–93% (Kappa = 0.89–0.91). Results showed that DTF and TDF remained largely stable throughout the study period, with limited conversion to other land-cover classes. Fragmentation analysis indicated declines in medium-sized DTF patches, whereas TDF remained stable in larger-patch classes with slight increases in smaller patches. Vegetation loss hotspot analysis showed oscillating hotspots as the dominant disturbance pattern, with no persistent and intensifying hotspots. Fire occurrence analysis similarly identified oscillating fire hotspots across the landscape. Despite localized disturbance and fragmentation, substantial areas of both vegetation types remained intact over the past 25 years. These findings establish a baseline for conservation planning and long-term monitoring of Myanmar's dryland ecosystems and highlight the persistence of DTF and TDF despite continuing land-use pressures.