Over 20 years ago, in his book We Only Have One Earth, Control Yuan member and environmental protection scholar Ma Yi-kung pointed out that many advanced countries had recognized the importance of trees in cities and had passed laws to protect them.
監察委員兼環保學者馬以工二十多年前在《我們只有一個地球》一書中就提到，許多先進國家早發現了樹在城市中所扮演的角色，紛紛立法保護。