There aren’t many deciduous trees that retain their leaves through the winter here in the temperate northeastern US. Perhaps the best known are those of several oak species (Quercus sp., Fagaceae). The family Fagaceae doesn’t just include oaks, however; it also includes the beeches (Fagus sp.)
While in southeast Ohio last week I noticed a lot of American beeches (Fagus grandifolia, Fagaceae) scattered across the Hocking Hills region. They stood out because like many oaks, they too held their leaves through the winter (a condition known as marcescence.)
It doesn’t seem well-known why members of the family Fagaceae exhibit marcescence. One source suggests that it may be an advantageous adaptation to prevent herbivory. I’ve also heard it suggested that marcescence helps jump-start transpiration in the spring. By retaining leaves, trees can possibly use them to help pull water through their trunks when they break out of dormancy, but before they’ve grown new leaves.