Why do dead leaves stay on trees during winter?

"Not all trees drop their leaves in the fall. Even in the height of winter, a curious number of oak and beech trees refuse to let go of their brown, brittle foliage. The delicate corpses rattle on the living branches until the warm season returns. This is not a new phenomenon.For at least 2,000 years, people have documented the unusual sightings where certain deciduous species hold onto their dead leaves. It's called "leaf marcescence" (pronounced mar-sess-sence), derived from "withered" in Latin."

"Scientists are investigating why some plants still wear last season's tattered clothes. They found a surprising number of species hold onto their papery remains - but the explanations are anything but cut and dried. "Marcescent trees have a certain beauty to them ... your eye is really drawn to these leaves that remain and rustle in the wind in the winter," said Mason Heberling, associate curator of botany at the Carnegie Museum of Natural History."

Some deciduous species, especially oaks and beeches, commonly retain dead brown leaves throughout winter, a phenomenon called leaf marcescence. Observations date back at least two thousand years. Deciduous trees normally withdraw nutrients from leaves before dropping them in autumn; marcescent trees instead keep brittle foliage attached until the growing season returns. Scientists are investigating ecological and evolutionary explanations, finding many species exhibit the trait and several competing hypotheses exist. The trait draws attention visually and complicates phenological datasets, prompting researchers to study its distribution and possible adaptive functions.

Read at The Washington Post