Tom's Blog

Tuesday, December 20, 2016

Buckthorn: Before and After Eradication

When we started restoration work at Pleasant Valley Conservancy in 1997 (almost 20 years ago), most of our savanna areas with calcareous soils were solid buckthorn. I remember those days but could not find any photos that showed it. Recently, digging through boxes of photos from those pre-digital days, I ran across this delightful photo from 1985!




Family photo from 1985 showing wall of buckthorn
I don't know the exact location, but I believe it is at the edge of the Unit 10 savanna. I remember that we climbed up to the top of the ridge and then, exhausted, sat down while Kathie took our picture.

The dense buckthorn thicket behind us is typical of what was there before restoration. You could not walk through the area without bushwacking. After the leaves came out, you could not see the big trees inside of the savanna.

I looked for a photo taken after restoration from a similar area. (Most of my digital photos have been indexed in Excel.) The one shown below is approximately the same site.

Photo of Unit 10 savanna taken in October 2010.
This savanna was cleared in 2001-2002. It has been burned annually ever since. At first it was hard to get the area to burn, but after a few years the new understory vegetation started to provide great fuel for burns.

How did we get rid of all that buckthorn? Originally by basal bark treatment with Garlon 4 in oil. (We used to buy a Garlon 4 pre-mix product in 6 gallon pails.) Pat Schrader did most of the work. He set up 100-foot-wide swaths, starting at one edge of the unit and moving all the way through to the other edge. Most of this work was done in the winter. (In those days we had some mostly snow-free winters.) The following growing season the treated buckthorn did not leaf out. After two or three years, the dead roots rotted off and the plants could be easily pushed over by hand. They then provided a good base for a burn pile.

I think this sort of basal bark treatment is the best way to get rid of buckthorn patches as dense as these. It is lots less time consuming than cutting and treating the cut stems with herbicide, providing you aren't in a hurry to get the area cleared.

Just to be clear: getting rid of the big buckthorns did not get rid of the buckthorn! There was a seed bank, as well as lots of dormant buds on underground root collars, some of which resprouted years later. I discuss this phenomenon in a separate post.

But with persistence we have now virtually eradicated buckthorn from our savannas!



1 Comments:

Blogger Michael Nied said...

Wow that's incredible! Also a good reminder that I need to take more "before" pictures in the areas I work on.

December 21, 2016 at 6:31 AM  

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