Section chief Wu Hui-lung of the Council of Agriculture, who is responsible for water and soil conservation, says that 966 hectares of land along the Mt. Ali highway were previously all heavily forested, but since the road was built, areca palms, tea plantations and vegetable patches have replaced almost two-thirds of the forest which protected the soil and soaked up water on the mountain slopes. The situation in Nantou County is similar.
農委會主管水土保持的科長吳輝龍即說，阿里山沿線公路上九百六十六公頃的土地原來都是茂密的森林，但公路開通之後，檳榔樹、茶園、菜園取代了幾近三分之二涵養山坡水土的森林，而南投縣情形也類似。