Plan To Plant Over A Billion Trees Limited By Lack Of Seedlings

In order to fulfill the ambition of the United States federal government’s REPLANT Act, the U.S. Forest Service has funds available to plant more than a billion trees in the next nine years. The problem is, there aren’t enough trees. Not only that, but U.S. tree nurseries don’t have enough variety of species.  A new study by scientists at the University of Vermont (UVM) has shown that the limited diversity of tree species available has frustrated how much the forest service can do.  The research team found that forest nurseries have a tendency to keep a limited inventory of a few tree species, such as those used in commercial timber production, rather than species necessary for ecological restoration, climate adaptation or conservation. In many areas, no locally adapted trees were available.  The researchers said a much larger amount of seedlings and diversity within those is needed at regional nurserie.  This is exacerbated by seedlings being sensitive to stress. A mismatch between when they are available, such as earlier in nurseries farther south, and when they need to be planted, like in northern soils after the last frost, could be an issue.  Government agencies like the U.S. Forest Service, as well as state governments, rely on seed zones from the 1970s based on climate conditions that are very different from those predicted for the future.