Text Size:   A+ A- A   •   Text Only
Site Image
Data Information and Reporting for Indicator F.b.
Oregon Indicator of Sustainable Forest Management F.b.
Tree mortality and damage from insects, diseases, and other agents

Forestry Program for Oregon Strategy F:
Indicator F.b. is one of three indicators that will measure progress towards achieving Forestry Program for Oregon Strategy F: Protect, maintain, and enhance the health of Oregon's forest ecosystems, watersheds, and airsheds within a context of natural disturbance and active management.
Quick Links -
Other Indicators for
Stategy F Reporting

Desired Trend
No invasive species on Oregon’s “100 Most Dangerous” list are uncontained in the state’s forests, and a stable or decreasing forest acreage is affected by invasive species. 

At-a-Glance: Condition, Trend, and Information

This is a symbol for the condition being fiar
This is the symbol for the trend being uncertain
This is the symbol for the information being partially available

Why is this indicator important?
A photo of false brome - an invasive grass species threatening Oregon's forests
False brome - an invasive grass threatening Oregon
Invasive species constitute a major threat to the integrity of native forest ecosystems. Oregon’s mild climate, coupled with recent increases in commerce and population, has facilitated the introduction and spread of invasive pests.
Invasive species reduce the diversity found in native forests, and adversely affect populations of native species through predation, competition, altered fire regimes, or destruction of habitat. Exotic pests can have significant economic impacts by direct damage to natural resources or the loss of markets through quarantine regulation.
Monitoring the detection, spread, and eradication efforts for new invasive pests can provide an early warning to policy makers and the public on species that threaten native and urban forests.

What does this indicator tell us about sustainable forest management?

 This is a symbol for the condition being fair

In 2009, exclusion efforts for invasive species in Oregon met the target of less than one failure for the Oregon Invasive Species Council (OISC) “100 most dangerous.” In the eight years since this benchmark was established, only two species from the list of invasive species have become established (New Zealand mudsnail and Portugese broom), with one other in danger of becoming established (feral swine).
Surveys for many of the highest priority invasive species were completed by state agencies and eradication projects targeting several introduced species are being carried out.  These include: treatment of the pathogen Phytophthora ramorum (sudden oak death); insect pests including granulate ambrosia beetle, gypsy moth, and Japanese beetle, and several invasive weed species.  Advances were also made in reporting of invasive species (database development), as well as education (invasives species calendar), the statewide action plan (passage of 11 initiatives), and trust account (increased state and federal funding).
The Oregon Department of Forestry-USDA Forest Service cooperative aerial survey of Oregon forest lands estimated that established invasive insects and diseases occurred on an average of over 150,000 acres per year from 2005-2009.  The predominant agents were defoliating and sap-feeding insect pests, and damage was greater in eastern than in western Oregon.  Recent infestations have occurred primarily on federal forest lands.  Trees affected included true firs, Sitka spruce, five-needle pines, Port Orford cedar, and western larch.  Average infested acreage was nearly 1.5 times higher than the previous five-year average.  The large increases observed over the last decade are due to many factors including increased pest expansion as well as the development of better aerial survey detection methods.


 This is a symbol for an uncertain trend
The OISC “100 most dangerous” invaders list is based on the consensus of state and federal scientists, and, as such, the list is subjective and may frequently change, making trend analysis difficult.   Detection, education, planning, and eradication efforts against invasive species appear to have consistently improved since 2002, but as Oregon continues to be subjected to new invasive species which have varying potential to destroy forest resources or affect quarantine, it is difficult to predict future trends.  The addition of a state invasive species coordinator and expansion of activities and funding available to OISC and cooperating state agencies will continue to improve efforts to exclude and contain invasive species in Oregon. 
Cooperative aerial survey observations of invasive insects and diseases is available going back several decades, but detection of these pests has often been obscured by weather, host development, or survey timing.  As such, annual results are highly variable and better expressed as five-year averages.  For many invasive species, long-term trends can be deceptive as the large numbers of hosts are frequently damaged or killed, and thus detection can decrease in relation to early stages of infestation while the invasive continues to expand.  Interpreting current results and predicting future trends will likely continue to be difficult.  Continued eradication of gypsy mnoth has prevented it becoming established in Oregon, while treatments for P. ramorum have resulted in its distribution being limited to a very small area near Brookings.


 This is the symbol for partially available information
Data on invasive species in Oregon is generally quite limited. The Oregon Departments of Agriculture and Forestry conduct annual trapping and monitoring efforts for high priority invasive pests and provide information on detections and ongoing eradication efforts.  The OISC produces an annual list of the “100 most dangerous” invaders and a report card/rating of current exclusion efforts.  Since 2007, in addition to an overall score the report card also includes separate evaluations for (i) reporting of invasive species, (ii) enhancing awareness through outreach and education, (iii) developing a statewide plan, (iv) administering a fund to support activities, and (v) success at excluding invasive species in Oregon.  These programs are well supported and can be expected to continue to provide information.  Annual aerial surveys and periodic ground surveys of forest lands provide information on some previously established invasive insects and diseases, but are insufficient to detect new arrivals. No source has been identified that could provide statewide data on the distribution and abundance of invasive plants on forest lands.

Types of information produced by this indicator
This indicator will provide tabular and graphaical information on the spread of selected invasive species and on the success of Oregon in controlling new invasive species introductions.

Report: "100 most dangerous" Invasive Species in Oregon
Table 1.  The Oregon Invasive Species Council (OISC) exclusion and containment record for the "100 most dangerous" invasive species in Oregon, number of significant detections, and actions taken, and overall annual rating (2002-2006).

OISC Annual Report
Number of OISC 100 most dangerous invasive species successfully excluded or contained
Number of important invasive species detections and actions taken1
Invasive species exclusion annual "report card" rating for Oregon 
1Numerical score represents the number of OISC "100 most dangerous" invasive species successfully excluded or contained during that year.
2Does not reflect detections at ports of entry, only involves species that have already penetrated the national border protection system.  Important species detections are high priority invasives found by trapping, surveys, or notification from public or private entities.  Actions taken generally refer to eradication efforts or the enacting of a quarantine area. 

Report: Overall Report Card on "100 most dangerous" invasive species in Oregon
Table 2.  The Oregon Invasive Species Council (OISC) overall report card score, evaluations of its five mission areas, and the exclusion and containment record for the "100 most dangerous" invasive species in Oregon (2007-2009).

OISC Annual Report
Overall Score1
(i) Reporting Invasive Species
(ii) Outreach and Education 
(iii) Statewide Action Plan
(iv) Trust Account
(v) Success at Excluding Invasive Species2
1In 2007, an OISC committee developed new grading criteria that reflect not just the overall state of invasive species, but also the work of the council in its five missions.
2Numerical score represents the number of OISC "100 most dangerous" invasive species successfully excluded or contained during that year. 

Report: Acres Infested by Gypsy Moth and Sudden Oak Death
A chart showing the acreage of Oregon forestlands infected by two significant invasive species - gypsy moth and sudden oak death
Figure 1 - Estimated area (acres) infested by two significant invasive species in Oregon forests - gypsy moth and the pathogen (Phytophthora ramorum) responsible for sudden oak death. Eradication effortrs for gypsy moth and sudden oak death date back to 1977 and 2001, respectively.
Click here to display a full-page-sized PDF version of the above chart

Report: Acres Infested by Invasive Insects and Diseases
A chart showing the acreage of Oregon's forests infested by invasive insects and diseases
Figure 2 - Five-year averages for the area (acres) estimated to be infested by established invasive insect and disease species in Oregon forests (1980 - 2009)1.  These include balsam wooly adelgid, larch casebearer, spruce aphid, and satin moth insect pests, as well as Port Orford cedar root disease and white pine blister rust.
1Five-year averages are provided due to the high degree of annual variation in invasive insect and disease detection.  Recent increases in detection reflect the development of better aerial survey detection methods, as well as pest expansion.  Typically, eradication projects target recently introduced invasive species and not established species.
Click here to display a full-page-sized PDF version of the above chart

Evaluation by the Oregon Roundtable on Sustainable Forests on this indicator

Metrics and Data Sources

Data Source
Annual exclusion and containment record (report card) for OISC "100 most dangerous" invasive speciesOregon Department of Agriculture
Oregon Invasive Species Council
Oregon Department of Forestry
Estimated area affected (acres) by recently-introduced and established invasive insects and diseases (five-year averages)Oregon Department of Forestry
U. S. Forest Service Forest Health Protection and Forest Health Monitoring

Related State, National, or International Indicators
  • Montreal Process: Criterion 3 – Maintenance of forest ecosystem health and vitality: 2003 Indicator 15: Area and percent of forest affected by processes or agents beyond the range of historic variation and 2010 Indicator 15: Area and percent of forest affected by biotic processes and agents
  • Heinz Center: Area Covered by Non-native Plants: What percentage of plant cover in forests is not native to the region?
  • Heinz Center.  Forest Disturbance: How many acres are affected each year by fires, insects, and disease?
  • Northeastern Area: 3.7 – Area and percent of forestland affected by potential damaging agents
  • Oregon Benchmarks: Environment--90: The number of most threatening invasive species not successfully excluded or contained since 2000
  • Oregon State of the Environment Report: Number of nuisance invasive species