This is such a gorgeous painting in person. I painted this with so much oil paint. No fillers all good rich oil painting of the highest quality. I used brushes and palette knifes. The trees is what I remember from growing up in Alsace France. Same in Germany where I lived later. The story goes that during hard times and war people used to cut off just the new branches for firewood.
They left the trunk and tree alive so it could later made new shoots and more fire wood. This is why these trees look like they do. You see them occasionally in VanGogh’s paintings as well.