Correction – Tree Invasion

Thank you to a couple people, particularly Dan Carter, for pointing out an inaccuracy in my last post about woody expansion in prairies.  In my second paragraph, I said that woody plants had expanded in Konza Prairie (Kansas) under annual fire.  That’s not correct.  Woody plant abundance has actually changed little in annually burned prairie units, but abundance has increased dramatically in units burned at 4 year intervals (and at longer intervals).  I’ve corrected that text now, but wanted to let everyone know about it.

I don’t think this changes anything else in my post.  Changes in fire frequency alone are unlikely to be the sole reason that woody plant expansion appears to be more rapid now than several decades ago.  I’m sure I’m not the only one who has observed smooth sumac (Rhus glabra) increasing under 3-year fire frequencies, for example.  In addition, I know of prairies that went through decades without any fire at all and didn’t appear to experience rapid woody plant expansion until the 1970’s or later.  It’s a big and complicated puzzle.

Regardless, the text in the post should now be correct!

If you haven’t done so, I’d encourage you to go back and read the many comments attached to the initial post.  There are some excellent responses and ideas from a number of readers.