6.2. SR 03-25-1996 - Laserfiche WebLink

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26401 180th St. Big Lake, MN 55309 (612) 263-8522 TO: FROM: DATE: RE: Steve Ach, Elk River City Planner Tim Edgeton, County Forest Resource Specialist January 22, 1996 Forest Health Assessment for Oak Creek Estates - Preliminary Plat On January 10, /g96 i mci on-site wi[it Steve ,Johnston, Engineer for Landfor~n Engineering Company to review the Oak Creek Estates development. In making the assessment, I used data from the field inspection, from aerial photographs, from our oak wilt inventory maps (produced by the DNR), and from the survey maps supplied by Landform Engineering showing topography and proposed grading plans. Below is a summary of that inspection. Attached is a map outlining the approximate location of dead areas and the oak wilt sites (according to inventory). .j The land is heavily forested with a few small clearings. The primary forest cover type consists of northern pin oak and bur oak. Other species present include elm, cherry, birch, aspen, and boxelder. Understory vegetation consists mostly of hazel and prickly ash. The health and condition of trees varies with species and location. The higher elevation areas are comprised mostly of bur oak. These trees appear to be in good condition. Both mature and younger age classes are present. The lower elevation areas seem to have much more mortality. Both pin oak and bur oak are found in the lower areas, but much of the pin oak is dead and either still standing or already on the ground. Of the 2 or 3 large dead forest areas in the development, they ali seem to be in Iow elevations. Because of this, there is a good indication, that the dieback was due in part to droughth. Although the oak wilt inventory maps show 2 distinct oak wilt infection centers present, ! could not confirm any oak wilt during the inspec[ion.. ! would strongly recomme;]~ however, that it be checked again for oak wilt sometime this spring or early summer. There is no charge for this and if oak wilt is diagnosed, the County Cost-Share Program is still available. Overall, the south 1/2 of the development is where much of the standing dead trees are found. The far east 1/3 of the development seems to be in excellent condition and the north 1/2 is in good condition. Again, the dead areas seem to be found in the Iow elevations. The terrain is quite rolling with hills located throughout development. The rolling topography will definitely make grado changes near trees more likely than a fiat area would. Generally, the more grade changes that occur near trees, the more mortality will occur. Unfortunately, the dieb~ck usually doesn't show up until 2 to 4 years later, so there is no easy or immediate way to tell if damage was done. Therefore, in areas where trees wish to be saved or preserved, minimizing the grade changes near them will be very important. Because pin oak are especially intolerant to grade change, be aware of their locations. For assistance with tree preservation techniques, please feel free to contact me. If you have any further questions, call me at 263-8522. Thank you.