91热爆

In Florida and Georgia it is so warm in winter that some broad-leaved trees like oaks do not shed their leaves but keep them throughout the year and continue growing. There are also pine trees growing here. Although most pines grow where the soil is poor and where no other trees can survive, some of the pines here grow because of forest fires. Oak saplings are killed quickly by fire, but the terminal buds of young pines are surrounded by a shock of needles that burn at relatively low temperatures and do not have time to damage the bud. These fires are natural and are started by lightning that tends to strike the taller trees, leaving deep scars where the lightning makes its way to the ground. The pine needles on the forest floor ignite easily, but they burn at low temperatures and the flames are short-lived.