TREE COUNTING LOCATES VULNERABLE ASH TREES

Emerald ash borer’s steady destructive movement toward Sheboygan County was discussed in last week’s column.

It was mentioned that several state agencies and departments – the State’s Department of Agriculture, Trade & Consumer Protection, Wisconsin Department of Natural Resources Urban Forestry, as well as Sheboygan County’s University of Wisconsin-Extension, Land and Water Conservation Department, and Planning and Resource Department – worked together to develop an Emerald Ash Borer Resources Management Plan (it is presently in draft form for review) for Sheboygan County communities.

It involved a great deal of work at a modest cost, mostly completed through funding from a Sheboygan County Stewardship grant (which used only about $10,000 of the $15,000 made available) and the efforts of two skilled summer interns; and was done in cooperation with local units of government.

This week’s column will discuss some of the information gathered in the 214-page plan. In addition, more detailed information about the emerald ash borer can be found by going to the Sheboygan County’s University of Wisconsin-Extension’s Web page.

In the Resources Management Plan, community maps were developed showing the location of ash trees along public right-of-ways and some parklands. What is not shown are ash trees located in private back yards or extensive parks. Rural private wood lots were not surveyed and are likely to include a large number of ash trees that could be affected when the beetle reaches Sheboygan County. The management plan is intended to give communities an idea of the extent of the ash tree coverage within their areas and to allow each community to plan ahead.

The maps in the plan were interesting; they show the location of each tree surveyed. In the city of Sheboygan, 22,759 trees were inventoried and 5,154 were ash trees. Also recorded in each community were oak, maple, linden, honey locust, among others.

Village of Random Lake showed 159 trees inventoried with 57 trees being ash. The village of Cascade showed 67 trees surveyed with 27 being ash. Village of Elkhart Lake had 236 trees inventoried with 34 listed as ash. Village of Glenbeulah surveyed 199 trees, showing only 11 ash trees.

Village of Kohler had 852 trees surveyed with 203 being ash.

City of Plymouth had done their own tree survey in 2003, while the county surveyed in 2009; in 2003, 1,787 trees were inventoried and 371 were ash; the 2009 survey covered another 829 trees with 190 being ash trees.

Village of Howards Grove listed 278 trees with 112 trees being ash.

Sheboygan Falls listed 758 inventoried trees with 179 being ash trees.

Emerald ash borer adults are very small metallic-green beetles, about the size of a cooked grain of rice. The adults create a D-shaped exit in an ash tee as they exit in May through July. As they look for a mate, they seldom wander far from the tree in which they are born. Females will lay 60 to 90 eggs, one at a time, in the crevices of an ash bark. The adult lives only three-to-six weeks.

As the eggs hatch, they immediately chew their way into the tree. The larvae will feed under the bark for one and sometimes two years, and can survive in green wood, such as firewood, for an extended period of time (one of the ways the beetle is moved to other locations). In the autumn, after feeding under the bark, they will create a chamber for themselves in the tree’s sapwood. They will over-winter and pupate in the spring, turning into adult beetles.

By then, they will have done their damage.