This questions' premise is incorrect. Live trees can burn. You see, live trees are more resistant to fire (Generally) due to their water content and wet wood, more so after periods of rains. However, there are three major factors that mean live trees can burn, even though they are wet: The first is that they're not 100% alive. read more
Live trees most certainly can burn, if the fire is hot enough. You have to keep in mind that the primary driver of forest/wildfires is accumulated fuel. That is, dried leaves, twigs, dead plants, etc. read more
To help prevent fires in or near forest land during the forest fire season, the following steps should be followed: Check local regulations regarding permit requirements and "burn ban" restrictions. These are available from your municipality, fire department or department of natural resources. read more