Forest Health Monitoring (FHM) began in the north-central states in 1994. The objective is to monitor, assess, and report on long-term status and changes in forest health. This is done through assessing tree conditions, soil characteristics, lichens, and air quality on permanent plots established throughout the region.

In 1998, a total of 131 forested FHM plots were measured across the northeast. These plots included:

		3,060 trees
		569 saplings
		3,482 seedlings
		387 standing dead trees

Rotating Panel	1998 Plots by State State Forest Nonforest Illinois 12 61 Indiana 10 37 Michigan 45 32 Minnesota 30 57 Wisconsin 34 38 Totals 131 225
FHM plots are a systematic sample of permanent fixed area plots on a hexagonal base grid. The plots are measured on a four-year cycle such that 1/4 of the plots covering a state are measured each year. In addition, 1/3 of the plots measured in the previous year are remeasured. This is called a rotating panel with overlap.

Sixty-three percent of trees measured consisted of these five species groups.		Seventy-eight percent of all saplings measured consisted of these five species groups.

Eighty-four percent of all seedlings measured consisted of these five species groups.

One of the primary indicators of tree health is the condition of foliage. In 1998 of 3,060 hardwood and softwood trees measured, 96 percent were observed to have normal crown conditions in terms of foliage transparency, crown density, and crown dieback.	Crown density - the amount of branches and foliage that blocks light visibility through the crown. Crown dieback - recent mortality of fine branches and twigs. Foliage transparency - the amount of light visible through the live crown. Severe transparency can result from defoliation, disease, or stress.

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Trees with Poor Crown Conditions in 1998 (n)=total number of trees in the sample Severe Crown Transparency Poor Crown Density Moderate to Severe Dieback 2 other softwoods (330) 17 other softwoods (330) 20 other softwoods (330) 1 oak (272) 1 red pine (208) 6 oak (272) 1 elm (85) 1 Jack pine (26) 4 elm (85) 1 birch (137) 10 oak (272) 27 maple (808) 9 maple (808) 2 elm (85) 9 ash (207) 4 ash (207) 2 birch (137) 2 aspen (346) 2 aspen (346) 19 maple (808) 5 other hardwoods (165) 3 other hardwoods (165) 3 other hardwoods (165) 6 ash (207) 5 aspen (346) 2 basswood (59) 1 walnut (19)

In 1998, there were 387 trees recorded on the plots as standing dead. These standing dead trees represent cumulative mortality since the trees may have died recently or years ago. Dead trees represent 11 percent of the total number of trees observed on FHM plots in the north-central states.

In 1998 of 3,060 trees measured, 27 percent had at least one observable damage recorded (21 percent had 1 damage; 4.9 percent had 2 damages; and 1.3 percent had at least 3 damages observed). Species groups with the greatest number of trees with observable damage are shown below:

Species		Percent of Trees Sampled		Damage Observed
sweetgum		100 (1)		decay, broken branches
yellow-poplar		67 (3)		open wounds, vines
walnut		42 (19)		vines, loss of apical dominance
maple		38 (808)		decay, canker
basswood		37 (59)		decay

In general, the most frequently reported damages on all trees in 1998 were indications of decay, loss of apical dominance, cankers, and cracks/seams. For additional information contact: USDA Forest Service Northeastern Research Station Forest Health Monitoring 100 Matsonford Road 5 Radnor Corporate Center, Suite 200 Radnor, PA 19087-4585
	May 1999

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