Latest Score:

4.2/5

in 2019

score trend is flat over time
Weight: 20%

Forest damage is assessed by a visual inspection of forest damage via fixed-wing aircraft and reported in the Insect and Disease Surveys (IDS). IDS are conducted annually by the State of Vermont and the USDA Forest Service to map forest disturbance, including damage caused by insects, diseases, fire, weather events, or a range of other causes1. Although mortality is a natural occurrence within forests, widespread die-offs are indicative of stressors that may lead to diminished ecological function and ecosystem resilience. This metric is computed as the total area mapped with visible mortality that has occurred since the previous survey. A high score means that forest mortality is remaining low over time.

1USDA Forest Service. Forest Health Protection. Available at: https://www.fs.fed.us/foresthealth/applied-sciences/mapping-reporting/detection-surveys.shtml

Aerial detection surveys (ADS) are conducted annually by the Vermont Division of Forestry and USDA Forest Service to document the extent and severity of forest disturbance caused by insects, disease and abiotic factors throughout the state. These data offer a comprehensive assessment of the condition of forests across the landscape. Here, we quantify the total area mapped as mortality. The current year is scored as the difference between the minimum -10% of the range and maximum +10% of the range.

Interpretation provided by:

Josh Halman, Forest Health Specialist; Vermont Department of Forests, Parks and Recreation

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The score is calculated using a target value and the historical range of the the entire long-term dataset. The higher the score, the closer this year's value is to the target.

Once the score is computed for each year, the trend in scores over time is calculated. If the trend is significantly positive or negative, the long-term trend is marked as increasing or decreasing respectively.

Component Description
Scored as

Distance between minimum (-10%) and maximum (+10%) (scaled 1-5)

Target value

Data minimum

Directionality of scores

Lower values in the data are better

Minimum value used in scoring

Data minimum - 10% of the range

Maximum value used in scoring

Data maximum + 10% of the range

Insect and Disease Surveys (IDS) are annual aerial surveys of forests conducted by the state of Vermont and the USDA Forest Service to map areas of tree mortality1. While the program has been conducted for many decades in Vermont, the first year of digitally available data is 1995. This metric is computed as a sum of total area mapped with visible mortality in a given year that has occurred since the previous survey. We set the target for this dataset to be lowest possible acreage (either the minimum value in the data minus 10% of range or 0, whichever was greater). The current year is scored as the difference between the target and the upper scoring bounds (maximum value in the dataset plus 10% of the range), scaled to be between 1 and 5.

CONDITION INDICATORS