Saturday, May 14, 2011

American Chestnuts trying to return with human intervention.

A new article on the USDA blog discusses the progress being made in restoring the American Chestunt to the eastern US landscape.  This important species was virtually wiped out as a major forest canopy tree by the 1950s by a fungal infection introduced from China.

Human intervention is one thing.  True sustainability is a much slower process.

Test plantings of blight resistant Chestnuts grown in intense breeding (hybridizing) programs are now being established.  This is a very first step in a process that will take centuries to prove itself.

BTW, I have hundreds of the original American Chestnut sprouts on my 50 acres in Carroll County, MD, and have had some produce nuts.  Yes I've eaten native american chestnuts roasted over an open fire :-)

But here are some cautions:

(1) a monoculture planting of one cross does not consitute natural genetic diversity.

(2) will these planted seedlings naturalize (seed offspring in the wild)?

Not until these plantings naturalize, and/or until a diversity of blight resistant hybrids are developed, will we be assured a wild, self sustaining population. 

(3) Hybridization (I hybridize daylilies), particularly with intense selection for traits, notoriously introduces weak plants that may survive under culture, but can't compete in the wild.

(4) One final concern about naturalizing these is mentioned in the article--the problem of deer overpopulation. They ravage the understory through which seedlings must penetrate. Lack of wolves (root cause of deer overpopulation) is seriously damaging eastern forest ecosystems in general.

I've been following the progress of this important effort over the years, and it's good to see that they now have a result they can test in the field.  But there's still a mighty long way to go.

1 comment:

  1. I've seen the pictures of the replanting, but I wonder why they find it necessary to remove vegetation completely as you would for an orchard ? I clearly don't know all there is to know about Chestnuts, but i have to believe that a healthy underground mycorrhizal grid left intact and kept alive by other trees and shrubs would have been the way to go. At least just simply thin the woods. sometimes well intentioned ideas mean well, but hurrying a natural process or actually trying to force success can do more harm than good. I know, for yesrs in the 1970s, I practiced some of the usual conventional thinking of clearing land of any perceived competition and had failure after failure until I actually left alot of the land in it's natural state and utilized Nurse Trees.

    The US Forest service in California is doing this exact same thing by Chaparral clearing after fires and has actually increased pine seedling loss. Somehow Native species are viewed as invasive and evil. Cuyamaca State Park in San Diego County is a prime example.

    Just my two Kronor!