Have you watched children just before bedtime on a day when they have played hard and filled with fun? There's a sudden burst of energy in a last minute refusal to give up and go to sleep for the day, perhaps a bit uncertain whether the next day will bring as much delight as the one passing into history. They fight sleep as hard as they can and want so badly to stay awake and stretch the day out as long as possible. They play briefly with a toy and abandon it for another, laugh, jump and refuse the bonds of slumber. But finally, they can fight it no longer and they give in to the inevitable. They sleep.
I think trees are like that. They awaken in spring to buds and blossoms that stretch into leaves and spend the summers waving gently in breezes, finding joy in gentle rains and in the animals that favor their branches. It's as close to an extended play day as trees can get and they make it last as long as possible, fighting sleep the entire time. When fall comes, trees expend a last burst of energy, displaying brilliant colors and they try desperately to hold onto their leaves through autumn rains and winds. But finally, they can fight it no longer and must give in to the inevitability of winter. They sleep.