Tree Risk Assessment of Date Palms with Aerial Roots Using Minimally Invasive Technologies

This study assessed the health risks of date palms in Taiwan with aerial root growth using visual tree assessment and minimally invasive testing. The phenomenon of aerial root growth on the outer side of the trunk is presumed to be a growth response of the palm to adapt to environmental changes, while the distinct dark stem tissue band between the decayed and sound stem tissue in the cross-section is likely a result of stem tissue variation. Key external defects included leaning and insect damage, while acoustic tomography confirmed internal structural variability but required accuracy improvements. Drilling resistance tests showed that healthy palms had the highest resistance near the cortex, decreasing toward the center, while decayed palms exhibited significant amplitude reductions. These findings highlight the need for comprehensive palm health assessments and provide a scientific basis for improved urban palm management and conservation.