A forest resource that is expanding and sustainable promotes economic strength in Iowa. A forest resource that is healthy contributes immensely to our state's goals of clean water, abundant wildlife habitat, and a level of outdoor recreation and urban aesthetics that enhances quality of life in Iowa.
Forest Health Monitoring Summaries For 2003:
The processes and techniques of forest health monitoring that produced these three broad observations are intense and ongoing. Each year, DNR staff performs aerial monitoring of the major forested areas in Iowa via chartered aircraft flights over 725,000 acres in major river valleys. Each year, field foresters covering the entire state report forest stressors both informally, and/or formally through written reports. Each year, the Iowa Forest Insect and Disease Management Council (IFIDMC) informs the Forestry Bureau of forest health problems noted around the state. IFIDMC is composed of entomologists, pathologists, arborists, foresters, and resource program leaders. Each year, the IFIDMC conducts a forest health tour around Iowa, which is a two-day field examination of sites and situations deemed of importance to forest health. All these sources of information contributed to the above three broad observations of forest health in 2003 and those three broad observations are discussed in more detail below:
1). Gypsy Moth and White Oak Decline demonstrated increased presences in 2003: WHITE OAK DECLINE: Rating reports from field foresters, field visits by entomologists and pathologists, reports from forest industry personnel, and aerial monitoring all concurred that white oak decline is increasing, especially in N.E. Iowa counties. One field forester expressed white oak decline as the most serious and important forest health issue in Northeast Iowa. Two important results occurred in 2003 in response to the increase in observation of this forest stressor.
GYPSY MOTH (L. dispar): Field monitoring demonstrated a significant increase of this insect in Iowa during 2003. Gypsy Moth (GM) trapping was coordinated by APHIS, assisted by IDALS and DNR during 2003 and over 3,500 field traps yielded 159 moths, an increase over 2002.
Gypsy Moth is not yet widespread as viable breeding populations in Iowa. For over a decade, pheromone trapping to identify early moth arrivals followed with treatments to eradicate early moth arrivals has kept GM out of Iowa. And, these trapping and eradication efforts are expected to keep Iowa moth free for additional years. However, Wisconsin entomologists report a quickening of movement of gypsy moth westward and this, combined with the increase to 159 moth catches in Iowa in 2003 pointed to the need to prepare for eventual infestation in Iowa.
Therefore, steps were initiated in 2003 to prepare for infestation. Iowa 's Gypsy Moth Position Paper was revised by a sub-committee of the IFIDMC during 2003. Revisions include plans for “slow the spread” (STS) programs for when viable populations of the moth do become established, plans for gaining budget support for STS and general suppression programs, and plans for increased involvement of stakeholders in GM programs and advisories. Increased trap catches, combined with monitoring of GM's westward movement warrant increased attention to this forest stressor and that attention is being given, and will continue to be given in coming years. (Gypsy Moth 2003 summary).
Common insects and diseases that annually stress our forests: Forest, and urban forest health is monitored and documented by field foresters via annual rating reports. These reports rate the severity of such common stressors as wilts, ash maladies and insects, anthracnose, borers, needle and leaf blights, scale, flood damage, aphids, animal damage, caterpillars, cankers and others. The severity is rated on a scale of 1 to 10 with 10 being most severe. 86% of rated categories were rated 5, or less in severity in 2003. Many field foresters rated common forest stressors as low, even very low. In aerial monitoring flights, foresters noted very few of these common stressors. Isolated incidences of paleness of new foliage in new growth on soft maple was noticed, along with the continuing Dutch elm and oak wilt symptoms. Dutch elm disease could be readily observed in all counties (as in previous years). The annual forest health tour discovered the normal range of common forest stressors, but not significant areas of defoliation. Local outbreaks of common stressors were reported sporadically and sycamore anthracnose was reported heavier in certain portions of the state (including central counties) but overall, common forest stressors seemed lessened in intensity during 2003.
Non-insect and disease stressors; drought and invasive plant species in 2003: During normal monitoring processes during 2003, weather events generally were not observed with great frequency. In aerial monitoring, only two areas were observed having wind damage. City foresters noted local incidences of wind damage to urban trees but large areas of downed timber, which commonly occur during Iowa tornado and straight-line wind events were not noted with regular frequency in 2003. However, weather damage from drought stress was noticed in South Western Iowa. Weather reports showed drought conditions in several parts of Iowa, and field inspections in Monona, Harrison and other Counties verified symptoms, where extensive forested areas of oak (primary species is bur oak) demonstrated foliage that had turned brown well in advance of normal fall coloration times.
The most recent FIA/FHM report on Iowa 's Forest Resources also identified those four plants as serious invasive species. Additionally, two sites with oriental bittersweet were discovered and evaluated by IFIDMC members during 2003, one in Delaware County, and one in Hardin County, Iowa.
Future Forest Stressors Of Importance
Iowa 's forest health is important economically and ecologically, and Iowa 's forest health is monitored consistently. Programs already in place monitored Iowa 's forests for insect and disease problems during 2003, and identified two forest stressors that are increasing in occurrence, gypsy moth and white oak decline. Additionally, several new programs, studies and documents were generated in 2003 to address forest health concerns in more depth. The Iowa Gypsy Moth Position Paper was revised. On-site studies of white oak decline were performed and documented on two occasions and in three counties. And, a grant for additional study of this decline was prepared and submitted. Such programs assist in ensuring the future health of Iowa 's forested lands and ensuring continuation of the products and values derived from Iowa 's forests.
Updated: February 2004
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