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> > I the ash from the property.This would be a large undertaking, as the ash would have to be removed and replaced by other floodplain species. Removal could be contracted to logging firms,which could potentially fund the work,though the market for ash in the county is relatively sparse and this technique unlikely to create any profit for the city.Ultimately, removal should occur once invasive species are removed,and could occur in stages (10-20%per year) to minimize disturbance to the community. However, removal will realistically have a large negative impact on the property,especially in floodplain areas and to neighboring trees.The removal would also have to be timed to minimize impacts on the prairie restoration process. Advice from the city or county should be solicited when making the final decision. Oak Wilt and Bur Oak Blight Oak wilt is an increasingly common tree disease caused by the fungus Ceratocystis fagacearum.While the disease is present in many eastern US states, it is most prevalent in the Midwest US.Within Minnesota, it is an issue of serious concern in and around the seven-county metro area, including in Sherburne county. Oak wilt affects all of Minnesota's most common oak species (red oak [Quercus rubra],pin oak [Q. ellipsoidales],bur oak[Q. macrocarpa], and white oak [Q. alba]),though it does not affect these species equally. Red and pin oak are the most susceptible species,with infected individuals wilting in six weeks or less. Bur and white oaks may take years to wilt completely and may only do so one branch at a time.The fungus can be transported from tree to tree by sap beetles,but most commonly spreads through root grafts.The beetles are attracted to the fungal mats created when mature oaks die from oak wilt, and also to wounds on uninfected oaks, providing a convenient pathway of spread for the fungus. Oaks commonly form root grafts between individuals,allowing direct transfer of the fungus from infected to healthy individuals. While Bailey Point has few red or pin oaks,there is a sizeable contingent of large bur oaks, especially in the grassland areas of the property.While this provides some hope that an outbreak of oak wilt at the property is less likely,the risk of infection remains. Careful monitoring of individuals will be necessary to identify and manage infected individuals. If infected individuals are found,root barriers may be installed around infected 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. 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 Friends of the Mississippi River Bailey Point Nature Preserve NRMP 67