Iowa's Forest & Tree Health
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Iowa's Forest & Tree Health 1996determining forest and tree health conditions Why worry about the health of our and distribution. Potentially the greatest threat forests? to our forests from the famous “Gypsy Moth,” not yet established in our state yet potentially Six percent (over 2 million acres) of Iowa serious, which required placement of is covered by trees and forests. Our forests have 5241pheromone survey traps by the IDALS significant impacts on our agricultural-based State Entomologist's Office to determine economy, protection of our drinking water infestation areas and sites in need of quick supply, critical wildlife habitat, and overall eradication efforts. enjoyment of the place that we call Iowa. Wood Recent efforts to develop vegetation industries employ over 7,000 Iowans producing management plans for selected state park and lumber and high quality wood products. Trees recreation areas utilizing Geographic in our small and large communities, our "urban Information System (GIS) mapping was forests," increase property values and conserve continued in 1996, utilizing DNR Forestry cooling and heating energy. Our forsets are aerial survey work. State park areas where this vital to our state's future. information is being utilized include: Backbone Because our forest resources are valuable State Park, Geode State Park, George Wyth to the citizens of Iowa, the Forestry Division of For More Information, Contact: State Park, Lacey-Keosauqua State Park, Lake the Iowa Department of Natural Resources Forest Health Program Ahqubi State Park, Palisades-Kepler State Park, (DNR) began monitoring forest and tree health Forestry Division-Iowa DNR Pikes Peak State Park, Prarie Rose State Park, conditions in the late 1970’s. This monitoring Wallace State Office Building Springbrook State Park, Viking Lake State Park, effort today is used to determine overall forest Des Moines, Iowa 50319-0034 Waubonsie State Park, Wildcat Den State Park, and tree health conditions, status of natural and (515) 242-5966 or Fax (515) 281-6794 and Wilson Island State Park. In addition, exotic insect and disease problems, and to significant areas of forest such as Loess Hills, provide up-to-date information for private and Under the Title VI of the 1964 Civil Rights Act, Section 504 of ShimekState Forest, Stephens State Forests and the Rahabilitation Act of 1973, The Age Discrimination Act of public managers to aid in the sustained Yellow River State Forest were also aerial 1975 and Title IX of the Education Amendments of 1972, federal management of Iowa's forest resources. regulations prohibit discrimination on the basis of race, color, surveyed during late July to determine the extent Cooperative monitoring efforts with Iowa national origin, sex or handicap. If you believe you have been of Oak Wilt and other forest health problems. discriminated against in any program, activity or facility as State University, the Iowa Department of An intensive survey was conducted in described above, or if you desire further information, please Agriculture and Land Stewardship (IDALS), write to: Director, Iowa Department of Natural Resources, cooperation with Iowa State University the USDA Forest Service (USFS), municipal Wallace State Office Building, Des Moines, Iowa, 50319-0034 Department of Plant Pathology in nine Iowa or the Equal Employment Opportunity Commission, Washing- foresters and private forest land owners, allows communities to determine the impact of a ton, D.C., 20240. efficient monitoring efforts. In addition, potentially serious dieback of Norway (Acer cooperation fosters improved communications plantanoides), Sugar (Acer saccharum) and to professional and to individuals on Iowa's Black (Acer nigrum) maples forest resource management issues. (major species in Iowa communities in urban Monitoring Efforts for 1995 settings) called "Hard Maple Decline." DNR Estimates of serious forest and tree health and municipal foresters assisted ISU in problems, such as insects, diseases, and flooding surveying impacts, were determined by aerial surveys of 474declining hard maples in Ames, Burlington, over64,500 acres of representative forested areas Cedar Falls, Cedar Rapids, Davenprot, Des across the state conducted during the summer of Moines, Fort Dodge, Maquoketa, and Postville. 1996. Visual surveys from DNR Foresters, Preliminary results indicate decline symptoms municipal foresters, and trained volunteers were could be due to improper planting techniques. Further research by Iowa State University's Printed on re- also evaluated as well as results from the Plant Disease Clinic at Iowa State University in Plant Pathology department will be supported cycled paper by the Department. of infection. Oak wilt is spread via root grafts and sap-feeding beetles. Although there is no cure for The famous 17 year locusts or cicadas (Magicicada Oak Wilt, control strategies such as preventing tree septendecim) made their appearance throughout wounds during high infection periods (April 1 to the Central Iowa area, causing not only lots of noise, July 1), disease containment by cutting roots of but small limb damage due to their egg laying infected trees, and killing oak trees surrounding activities. A brood is expected to occur in SW Iowa infected trees promptly appear to be the most in 1998. effective management options. The White Oak Dipolda tip blight on Austrian and family continues to show signs of decline due to the Ponderosa pine, Cytospora canker (Cytospora spp.) droughts of the late 1980’s and saturated soils of the on spruce, Anthracnose (Gloeosporium gridum) on early 90’s. Secondary diseases such as Armillaria ash and sycamore along with Aphids on ash and Root Disease (Armillaria spp.) and secondary insects Bur/White oak were observed in minor amounts. A like Two-lined chestnut borer (Agrilus bilineatus) Browsing damage by White-tailed deer rather large outbreak of Mimosa Webworm (Odocoileus virginianus) impacted 1,000 acres of (Homadaula anisocentra) was observed impacting Weather impacted over 170 acres statewide, including newly located areas in the Iowa Great Lakes region in forest and Christmas tree plantations, and natural honeylocust (Gleditisa tricanthos)in Central Iowa. The Winter - Spring of 1997 was below 1997. regeneration efforts in 62 counties documented by None of these appear to be threatening. normal in temperature and below normal in Dutch elm disease (DED), caused by the by DNR foresters. It is hoped expanded deer The weather was the greatest stressor of precipitation. Low winter temperatures , followed fungus Ophiostoma ulmi/novo-ulmi, has hunting seasons will bring the populations into line urban trees during 1997, several wind storms and by a warm/dry Spring, delayed bud break by an reestablished itself acrossed Iowa impacting 489 with habitat. the sudden snow storm in late October caused average of 2 weeks. Winter burn impacted conifer acres of American elm (Ulmus americana) and red Community Tree Results extensive limb and top damages to Silver maple, windbreak plantings across Northern and Eastern elm (Ulmus rubra). Much of the re-emergence of Iowa’s communities are dominated by three Siberian elm and many other tree species. Iowa. Severe wind storms and torandoes were DED is due to the high humidity conditions of the major tree species: green ash, silver maple and Gypsy Moth in Iowa common during the Summer impacting areas of past few years and an increase in the number of 20- Norway maple. These trees are subject to The Gypsy Moth (Lymantria dispar) is a Knoxville and Davenport. Warm temperatures and 30 year-old American elms that have naturally tremendous environmental stresses caused by potentially serious insect defoliator of Iowa’s native low rainfall during the late Summer to earlyAutumn regenerated in bottomland areas across the state. severely compacted soils, weather extremes and deciduous trees and forests. Since 1981, the State delayed leaf drop and fall color. A major snowfall Lack of sanitation and removal of infected trees has human abuse. These stresses often cause Entomologist has been trapping and eradicating on October 26th caused extensive limb damages to contributed to the increase by providing breeding opportunistic secondary insect and diseases the Gypsy moths associated with accidential trees in 52 counties across the state. A total of sites for fungus carrying bark beetles. chance to become established and cause gradual introductions coming into Iowa. One major 10 acre 58,000 urban trees had significant damage, resulting Dipolda tip blight (Sphaeropsis sapinea) tree dieback and mortality. eradication project was conducted by the State in over $5.1 million in clean up costs in 80+ Iowa continues to damage non native conifer plantations, The impact of the floods of 1993 are still Entomologist in cooperation with USDA APHIS communities. As a result, President Clinton declared windbreaks and ornamental plantings of Austrian being felt by trees growing in poorly drained clay within the community of Dundee in Delaware county on November 20th, 13 counties as Disaster areas. pine (Pinus nigra), Red Pine (Pinus resinosa), soils due to the past saturated conditions. Over during June of 1997. Infested nursery stock had Forest Results Ponderosa pine (Pinus ponderosa) and Scotch Pine 2,000 mature white/bur oaks were removed by been outplanted unknowingly by a homeowner as a Oak Wilt, caused by the fungus Ceratocystis (Pinus sylvestris), impacting 170 acres. In addition, municipalities and homeowners in 1997 due to windbreak.