Agenda - Council - 09/27/1994 - Laserfiche WebLink

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APPENDIX B TREE AND SITE RELATED DISTURBANCES A. Direct physical root damage most frequently occurs during site clearing and grading operations4 where transport (feeder) roots are cut, torn, or removed. 1. ~ Transport and feeder roots tend to tangle and fuse among the roots of adjacent tr~.es. The removal of trees with heavy machinery along the outer periphery of a tree save a~a causes root damage. 2. I The most substantial form of root damage for all root types occurs as torn or shredded tloots. Roots are cut in grade reduction, excavation, and trenching for.- undergrour~d utilities, sanitary sewer, or storm sewer lines. 3. A more subtle type of root damage is the loss of feeder roots. Since feeder roots norm:tlly occur within the organic layer and the surface four (4") inches of top soil, these roots :an be easily damaged by the compaction from vehicle and machinery passage, or tempora: y traffic. The stripping of top soil wilhin a tree's critical root zone can totally eliminate it,/ feeder root system. 4. Six to eight (6"-8") inches of wood chips can mitigate or protect roots from necessary t~affic or transport. B. Indirect root damage through site modification can result from positive grade changes, te{'nporary 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 levdls. An increase in soil carbon dioxide and other toxic gasses can also occur, leading to la[rge areas of anaerobic conditions. Anaerobic soil conditions cause a decrease- in the root r~:spiration process which is essential for the uptake and transport of rninerals and nutrientg. 2. ~ Anaerobic soil conditions are also produced by soil compaction, the increase in soil bulk ~lensity with a decrease in soil pore space. Compacted soil is also impervious. to root penetration, and thus inhibits root development. Soil compaction is generally caused by tge weight and vibrations of heavy machinery, vehicle parking, and the storage of fill and/oriconstruction materials within the root zones of trees. 3. .! Changes in soil chemistry will adversely affect tree survival. The most frequent ocdurrence is the change (decrease) in soil acidity by concrete washout. Most trees native !o Anoka County area prefer slightly acidic pH soils; concrete residues have high (basic) PH values. The leakage, spillage, or rinsing of toxic materials such as fuels or paints can he'.fatal for trees. C. Trunk_. and crown disturbances are generally mechanical in nature and are either caused directly by clearing and grading machinery, or indirectly by debris being cleared and falling into rr~es marked for prmecfion. 1. Common forms of damage include ,slripped bark, split trunks, and broken limbs. 2. : Damage also occurs from the posting of signs such as building permits, or~ survey markers on trees. 3. ~ Indirect damage can.be caused by open burning too close to trees. The possible range of damages include scorched trunks with cambial dieback, the loss of foliage due tc~ evaporative heat stress (leaf desiccation), and completely burned trunks and crowns. Ope~h burning permits are required in the City of Ramsey and may be available for disposal of tr~e debris. Permits are not available for construction and demolition debris. Open burnin~permits require application, inspection and volume based fee structures.(City Code 7.83 Bqrning Permits).