Most of the affected areas are located within the park's strictly protected and ecological restoration zones, primarily in low-density natural forests with timber reserves of between 10 and 50 cubic metres per hectare.
Park officials said preliminary assessments had identified several factors contributing to the degradation.
Many trees have reached old age and are dying naturally, while climate change and the spread of climbing plants have further weakened forest stands, making trees more susceptible to collapse.
Prolonged flooding has also played a role. Officials said extended periods of inundation had weakened soil stability and washed away peat layers, leaving tree roots less secure and increasing the risk of trees toppling.
Authorities warned that forest degradation and tree falls could continue if no effective measures are taken.
One of the main challenges is that most of the degraded forest lies within the park's strictly protected zone, limiting the range of restoration activities that can be carried out.
The park has proposed conducting further studies into the causes of degradation and testing controlled water-management measures to support forest recovery and guide future conservation efforts.
U Minh Ha National Park is one of the Mekong Delta's most important wetland conservation areas and forms part of the core zone of the UNESCO-recognised Mui Ca Mau Biosphere Reserve.
The park is known for its melaleuca forests growing on peatland and provides habitat for numerous rare and scientifically valuable species.
