Monday, January 16, 2017

Status of Girdled Trees Project

Back in May 2015 I girdled and applied herbicide to the large trees in this area in an attempt to create a grassland corridor between two areas of healthy prairie.  I thought it would be a few years before any of the killed trees began to fall.  Things are progressing much more quickly than I imagined.

In only a year and a half, about a third of the girdled trees have already fallen.  With one exception, all of the fallen trees have been Tuliptrees. 

Some of the trees dropped into the neighboring prairie.  Since this area is still being treated to eliminate invasive shrubs, I’ll remove the fallen trees to make it easier to find and destroy any invading sprouts.

The trees broke just above the girdle ring.  The girdling was done high enough on the trunk that a tall stump remains.  It’s best to leave the stump tall enough to be visible in the grass.  This way you are less likely to fall over or run your mower up onto the stump.

It looks as though the dead trees hosted quite a few wood boring insects.  I was surprised to see the extent to which the wood had been penetrated.

Woodpeckers appear to be taking advantage of the insect laden tree trunks.  I thought some of the trees were large enough to serve as woodpecker nesting sites, but I don’t think they are going to be standing long enough to serve that purpose.  I’m expecting this tree to fall soon.

In June 2016, about a year after being girdled, the Tuliptrees were still producing leaves on a few branches.  I was having some doubts that I had successfully killed the trees.

The trunks themselves gave some positive evidence that I was getting the desired results.  Impressive fungus growths suggested that decomposition was occurring beneath the bark.

A variety of fungus species were present.

I was impressed by the number of fungus species that were able to so quickly take advantage of the recently killed trees.

This area will soon be dominated by tall grass, but it won’t be without a few trees.  I have left several young Blackjack Oaks, Quercus marilandica, to grow among the grass.  Blackjack Oaks have a special relationship with several prairie invertebrates, and are well worth saving.  There won’t be enough trees left to hinder the growth of the prairie grasses, but there will be enough to enhance the quality of this small area.

You can read about the original girdling project by clicking HERE.  


  1. Replies
    1. Thanks, Lois. It's not a technique you want to use in your yard though.