06/27/2001 Env Bd Packet - Laserfiche WebLink

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TREE PRESERVATION POLICY die or appear to be dying within one year of planting by the person responsible for the planting. c. Before any construction or grading takes place, snow fencing or erosion control fencing shall be placed around the borders of woodlots of the driplines of large trees to be preserved. Signs shall be placed along this fence line prohibiting grading beyond the fence line. SECTION V. TREE AND SITE RELATED DISTURBANCES A. Tree protection zones, specimen trees or stands of trees designated to be saved must be protected from the following damages which may occur during all phases of land disturbance and construction processes. Methods of tree protection and disturbance prevention are provided in Section IV. 1. Direct physical root damage 2. Indirect root damage 3. Trunk and crown disturbance B. Direct physical root damage most frequently occurs during -s -ite clearing and grading operations, where transport or feeder roots are cut, torn, or removed. 1. Transport and feeder roots tend to tangle and fuse among the roots of adjacent trees. The removal of trees with heavy machinery along the outer periphery of a tree save area. 2. The most substantial form of root damage for all root types occurs in the form of cut roots. Roots are cut in grade reduction, or from trenching for underground utilities, sanitary sewer, or storm sewer lines. 3. A more subtle type of root damage is the loss of feeder roots. Feeder roots normally occur within the organic layer, and the surface four inches of top soil, subsequently, these roots can be easily damaged by the track action from a single bulldozer pass. The stripping of top soil within a tree's critical root zone can totally eliminate its feeder root system. C. Indirect root damage through site modification can result from positive grade changes, temporary storage of fill material, the sedimentation of erosion materials, soil compaction, and soil chemical changes. 1. Positive grade changes from fill and sedimentation causes a decrease in soil oxygen levels. An increase in soil carbon dioxide and other toxic gases can also occur, leading to large areas of anaerobic conditions. Anaerobic soil conditions cause a decrease in the root respiration process which is essential for the uptake and transport of minerals and nutrients. 2. Anaerobic soil conditions are also,produced by soil compaction, the increase in soil bulk density with a decrease in soil spore space. Compacted soil is also impervious to root penetration, and thus inhibits root development. Soil compaction is generally caused by the weight and vibrations of heavy machinery, vehicle parking, and the storage of fill and /or construction Page 4