The yellow splotches in my banner photo above are willow whips that have been laid out on the ground to, I assume, dry. The trees are cut back ("coppiced" or « élagués ») every year in late winter. The senior Monsieur Denis, now in his 80s, does the élagage or taillis (pruning). He must enjoy doing it, because he rarely does any other physical work around the vineyard these days.
These willows must be the tree called le saule doré or the golden willow. One site I've just read says they can become very big trees (height 20 meters) if they aren't coppiced annually. It says to beware of planting them close to your house because they have "far-reaching adventurous roots" that can damage septic systems and drainage pipes. It also calls them "highly ornamental."
The willow whips — or "rods" — can be used to make baskets. The local vignerons sometimes use them to tie up bundles of vine clippings (called sarments) that will be burned later in fireplaces or barbecue grills. The yellow whips are a nice touch of bright color in the winter landscape.
Another tree that adds color to winter scenes here is the oak. Its leaves turn a nutty brown in autumn but they don't fall until new growth replaces them in springtime.