New York Times: Over the winter, David Foster wanted to cut down some trees. His neighbor didn’t want him to. Foster is the director of the Harvard Forest, a 3,500-acre experimental forest in the middle of Massachusetts. When you are the director of an experimental forest, people aren’t sure you should be cutting down trees. “We’re cutting an acre of forest, nonnative conifers,” he told me calmly on a day in February, while grabbing some snowshoes. A forest ecologist will tell you that if you cut down some …