The study looked at different types of forests with a mix of masson pine and broad-leaved trees. They found that as the proportion of masson pine increased, the richness of shrubs in the forest also increased up to a certain point, then decreased. The height of shrubs fluctuated while the height of herbs decreased slowly. The coverage of shrubs tended to decline with more masson pine, but herb coverage stayed about the same. In all forests tested, shrubs made up most of the understory vegetation biomass, while herbs made up a smaller part. Overall, the total biomass of understory vegetation first increased and then decreased as the proportion of masson pine increased.