Add to ORKGIowa\u27s forest resources of primarily deciduous trees covers over 0.8 million hectares (2 million acres) of upland and floodplain sites too steep or too wet for traditional row crop agriculture. These limited natural forests along with urban trees and shelterbelts plantings of trees are critical for environmental and economic enhancement in the state. Although not yet established in the state, exotic insects, such as gypsy moth, Asian longhorned beetle, and pine shoot beetle, threaten native tree vitality. Established exotic diseases such as oak wilt and Dutch elm disease continue to plague the survival of Iowa\u27s oak and elm resources, respectively. Perhaps the greatest threat to Iowa\u27s forests is from exotic plants such as garlic m...