Study Finds Oversize Deer Herd, Exotic Plants Hurting Wisconsin Forest DiversityThe forests of northern Wisconsin have had significant losses of native plant species in the past 50 years, a new study concludes. The study blames an oversize deer herd and the arrival of exotic plants as key factors in the changes, which were not found on tribal forests where deer numbers are kept lower and development is closely controlled. Scientists at the University of Wisconsin-Madison did the comparative study by returning to forest tracts mapped in the early 1950s by the late John T. Curtis, author of "The Vegetation of...