Friday, May 30, 2008

Forest Health Review - Spring 2008

The current issue of the forest health review provides a detailed description of last years southern pine beetle activity as well as forecasts for this years southern pine beetle and gypsy moth activity. Also, updates on emerald ash borer, beech bark disease, the ‘Don’t Move Firewood’ campaign, and the Early Detection Rapid Response Program. An article on suburban forests details the problems posed by high deer densities and invasive species.
The full report can be downloaded at:

Thursday, May 22, 2008

Effects of Establishment Methods and Initial Seedling Size on Early Northern Red Oak Performance

In early 2006 the Virginia Department of Forestry installed a test of the effects of different establishment methods and initial seedling size on northern red oak survival and growth. There were two old-field locations, one in Louisa County and the other in Washington County.

Northern red oak seedlings from the DOF’s Augusta Forestry Center were graded into three root collar diameter classes – small (0.2 inches), medium (0.3 inches), and large (0.4 inches) and planted in early March 2006 using one of five establishment treatments: 1) no treatment; 2) VisPore mulch mat plus 4-foot Tubex tree shelter; 3) spot spraying of a 2-ft radius spot using a 2% glyphosate solution; 4) 4-foot Tubex tree shelter plus 2-ft radius glyphosate spot spraying; and 5) VisPore mulch mat only.

After two years, all the trees are off to a very slow start. Even the best of the seedlings have grown only about 1.5 feet in height and 0.06 inches in groundline diameter (GLD). But it looks like the way they are established (i.e. in tubes or not) has a lot more to do with their performance than does their initial size. And it seems as if the seedlings in the tubes are spindly - although surviving better and growing in height, they aren’t growing as much in GLD.

Comparing establishment treatments shows that the Tubex shelter was essential for survival / browse protection.

The VisPore mat and spot herbicide treatment resulted in similar survival and growth. There was no effect of initial seedling size on survival. The smallest seedlings have grown less than medium or large seedlings.

Without protective shelters, most of the seedlings in the study are either dead or in the severely browsed condition seen at left.