Soothsaying the 2010 Acorn Crop
Posted: March 30, 2010
30 , 2010- For Immediate Release
Contact: Allyson Muth, Phone: 814-865-3208, E-mail: firstname.lastname@example.org
Soothsaying the 2010 Acorn Crop
Written by Dr. Jim Finley, Phone: 814-863-0402, email@example.com
Part of the excitement of visiting a woodlot is to use some basic ecology skills to inform your understanding. This past fall an early snowstorm tore branches from many tree canopies and they are now strewn across woodlot floors. Of particular interest are the red oak branches -- many of which are still displaying the dry, russet leaves that had not fallen before the snow.
These branches have a story to tell. As with the leaves, many of these branches are still holding onto acorns that should have ripened and fallen last autumn. These are nearly full size and very evident. But that is last year's story. Clearly, in some parts of the state, there was a fairly good crop of acorns. These acorns are a form of mast -- or forest food -- which is very important to many of wildlife species. Deer, turkeys, bears, grouse and squirrels are very dependent on acorns. Foresters and landowners interested in regenerating red oak have huge interests in the red oak seed crop.
To use these fallen branches to predict the red oak acorn crop potential in 2010, it is necessary to know how long it takes an oak tree to grow an acorn. To start, generally, there are two oak groups for the species encountered in Pennsylvania. The white oak group includes: white, chestnut or rock, chinkapin, bur, and shingle oaks. These oaks have rounded leaf lobes. Most importantly, they produce an acorn in one growing season. A flower fertilized in the spring produces an acorn that fall -- one growing season.
The red oak group contains red, pin, black, scarlet, bear, and scrub oak. These oaks have "burs" on the ends of the leaf lobes. These oaks require two growing seasons to produce an acorn. That is, a flower that formed in spring 2009, if fertilized and retained by the tree, will yield an acorn in fall 2010. If you examine oak branches broken free last fall for immature acorns now, you have a pretty good idea if the red oaks in the woodlot will provide seed this fall. Those "baby" acorns, with a bit of imagination, are similar to full grown ones as they have a bulbous end and a slender neck where they attach to the twig. The leaf buds, which are clearly visible, are more conical, lacking the bulbous end (see attached image).
Many of the branches examined in central and north-central woodlots do not have immature acorns that should have started in spring 2009. What happened? It is not easy to say for sure as many events, including an annoying habit among oaks of not producing good crops regularly, can cause trees to abort acorns. You might recall, in the central parts of the state, there was a heavy frost on June 1, 2009. It was likely heavy enough to have killed the flowers.
As you walk through the woods, take a minute to look for 2010 red oak acorns. Seeing none, hope for a good flowering season in 2010 for red oak, to give us a crop in 2011. In some of oak woodlots, our best hope for acorns in 2010 is for the white oaks to have a good season this spring and to give us a crop of this mast for fall.
The Pennsylvania Forest Stewardship Program provides publications on a variety of topics related to woodland management for private landowners. For a list of free publications, call 1-800-235-WISE (toll-free), send e-mail to firstname.lastname@example.org , or write to: Forest Stewardship Program, Forest Resources Extension, The Pennsylvania State University, 416 Forest Resources Building, University Park, PA 16802. The Pennsylvania Bureau of Forestry and USDA Forest Service, in partnership with the Penn State's Forest Resources Extension, sponsor the Forest Stewardship Program in Pennsylvania.
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