In the winter the the tress are more dry and stiff from where there is not much hydration in the air and they are dry. They also lose their leave bc of the cold weather unlike spring when it rains a lot and the water can get back into the roots it get it’s hydration back and that is why the leaves start to grow and they actually change color too but it’s no noticeable. That’s why on the winter if you get a stick from a tree it’s easy to snap in half bc it’s dry and in spring it breaks but it’s more hard.
Hope it helped :)