But because of the nature of the terrain in some areas where disease is already present, such as along the Central Cross-Is-land Highway or the banks of the Tachia River, it would be "very difficult" to cut down pine trees growing on the cliffs in order to reduce the rate of infection.
但已出現疫情的中橫公路沿線、大甲溪沿岸，受地形限制，要將岩壁上的松樹砍除、減低感染率，「卻很困難。」