6.2 at 1 Camp Cozy Park_NRMP_2023

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79 Friends of the Mississippi River Camp Cozy Park NRMP Oaks commonly form root grafts between individuals, allowing direct transfer of the fungus from infected to healthy individuals. The Camp Cozy property has many red and pin oaks, and this increased the likelihood of Oak wilt infection, as these species are most susceptible. Careful monitoring of individuals will be necessary to identify and manage infected trees. If infected individuals are found, root barriers may be installed around those trees using a vibratory plow. Other options include soil sterilization and inoculation of high value individual trees. Care should also be taken to avoid injuring trees during the early growing season (April to July), when trees are most susceptible to the fungal spread. If a tree is injured during this time, covering the wounds is recommended. If pruning or other activities must be done, waiting for the winter is the safest option. Bur oak blight (BOB) may be a more serious threat to the oaks on the property. BOB affects only bur oaks and is most injurious to upland individuals in savanna remnants like at Camp Cozy. Caused by a species of fungus in the Tubaki genus, BOB causes lesions and discoloration of the veins on the underside of the leaves, eventually causing large portions of the leaf to die. In many cases, severe infections will cause tree death, though individual susceptibility to the disease varies. The fungus can overwinter on leaf petioles that remain attached to trees and is primarily spread by rain droplets moving spores throughout the tree. Early results suggest that inoculation of trees with fungicide may help slow or stop the spread of the disease within individual trees. At Camp Cozy, monitoring existing oaks for symptoms will be an important first step; moreover, if oaks are planted in the future, it may be beneficial to avoid planting the variety Q. macrocarpa var. oliviformis, which has shown the most severe susceptibility to BOB.