He points to the large planted mangrove forests of Fangyuan with some regret. He notes that the mouth of the Tanshui River up north is sandy. It has loose soil that erodes easily, so that mangroves serve a stabilizing function there. For that sort of coast, it is an excellent tree.
蔡嘉揚指著芳苑海岸大片的紅樹林感慨地說，北部淡水河口屬於沙質地，土質稀鬆易流失，紅樹林有「固沙」功能，是海岸保育的好樹種；然而在泥灘地上種植紅樹林卻適得其反。