1998 Forest Health Highlights - Michigan

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The Resource

Forests comprise 53% of the land area of the state, or about 19.3 million acres. These

forests are a critical component of Michigan's economy for the recreational opportunities

and the products they provide. Forestry related industries and manufacturing employ

150,000 people statewide and annually contribute $9 billion to the state's economy.

Additionally, forest-based tourism and recreation support 50,000 jobs and add $3 billion to

Michigan's economy. Michigan's forests contribute to clean air, water, and reduce soil

erosion. 

Special Issues

Incidence of the vascular disease oak wilt has increased in several areas around the Upper

Peninsula and the Northern Lower Peninsula of Michigan. In response, a statewide

interagency oak wilt initiative is underway, lead by the Michigan Department of

Agriculture and the Michigan Department of Natural Resources. This effort will focus on

detecting new and established oak wilt pockets across the state, and working with local

communities to suppress the spread of infection centers.

Detection will be accomplished through ground surveys conducted by state, federal, and

private foresters, consultants, and nursery inspectors. Information collected will be made

available on the Web in 1999. In addition, new high-resolution satellite imagery is being

evaluated for use as an oak wilt detection tool.

Michigan has experienced a hundred-fold increase in gypsy moth defoliation in the past

two years, with 301,778 acres affected in 1998. Much of the defoliation occurred in the oak

and aspen types of the east central Lower Peninsula, and in the mixed oak types of the

southwestern Lower Peninsula. Dry spring conditions have not been favorable for

development of the gypsy moth fungal pathogen Entomophaga maimaiga during this

period. In recent years, Entomophaga has been credited with dramatic collapses of local

gypsy moth population in the Lower Peninsula.

The 5-year Slow the Spread Project in

Michigan's Upper Peninsula ended in 1998.

The western Upper Peninsula will continue
1998 Forest Health Highlights - Michigan

file:///X|/netsite-docs/lps32615/1998%20Forest%20Health%20Highlights%20-%20Michigan.html[4/2/2015 11:22:13 AM]

to be part of a multi-state pheromone trap

monitoring effort. An isolated gypsy moth

infestation detected in Delta County in the

south central Upper Peninsula will be the

site of public education efforts designed to

help residents make informed decisions

about dealing with this pest.

A study by Michigan State University is

looking at the role of temperature in gypsy

moth egg mass mortality. Preliminary

indications are that exposure to high

daytime temperatures in late winter may

account for significant mortality of egg

masses located on tree trunks above

snowline.

The jack pine budworm defoliated 63221 acres in 9 counties in north central Lower

Michigan. Several stands have suffered two consecutive years of moderate to heavy

defoliation, and some topkill and mortality is expected in 1999. Extensive pre-salvage

operations are underway in the region to harvest older, high-risk stands of jack pine.

Other Issues

Windstorms and tornadoes damaged 70,241 acres of forestland across the two peninsulas

in 1998. A widespread, straight-line wind moved across Lake Michigan on May 31 and

damaged several stands across the central and northern Lower Peninsula. Salvage efforts

focused on removal of damaged pine to reduce the risk of bark beetle attack.. 

Sphaeropsis shoot blight-damaged red pine in several stands in the Northern Lower

Peninsula and the Upper Peninsula. Plantation and natural red pine growing in the open

and under mature red pine overstories were affected. In several cases, infection was traced

to wounds caused by hailstorm damage. Sphaeropsis damage in red pine growing west of

Manistique in the Upper Peninsula was occurred when infection occurred in wind-damaged

branches.

Low levels of spruce budworm defoliation were detected in isolated areas in the Southcentral and Western Upper Peninsula and on Drummond Island. This may be the beginning

of a regionwide outbreak, although historical records would indicate that a budworm

outbreak is still a few years off. The last epidemic began in the late 1960's and ended in the

early 1980's. Spruce plantations with minor balsam fir components have suffered periodic

defoliation from spruce budworm since the collapse of the last epidemic. 

Porcupine damage was at an all time high in Upper Peninsula red pine plantations. Aerial

photography was used to document and assess damage in the central part of the peninsula.

Complexes of spring defoliators were common in Upper Peninsula hardwoods last year.

Bruce spanworm and spring cankerworms damaged sugar maple in many areas.

Localized areas of heavier defoliation quickly reflushed by mid-June. This could signal a

building epidemic. Based on historical records that point to a ten-year cycle, forest tent

caterpillar populations are expected to build in 1999. The last outbreak occurred in the late

1980's and early 1990's. 
1998 Forest Health Highlights - Michigan

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Projects

The Michigan Impact Monitoring System (MIMS) is a long-term monitoring effort that

began in the early 1990's in cooperation with the University of Michigan and the

Department of Natural Resources. Extensive measurements are made each year on over 600

forested plots located in oak, aspen and northern hardwood stands across the Lower

Peninsula. To date, the data indicates that the region's forests are generally healthy, with the

exception of the northern pin oak type in the north-central part of the peninsula. Age,

drought stress, gypsy moth and other stressors have combined to cause significant mortality

in this type. Oak regeneration is also poor across much of this type, where feeding by deer

has also been a factor. Competition from red maple on many oak sites is becoming a

serious problem. Prescribed burns and herbicides are among the tools being considered by

land managers in an effort to maintain oak in these areas 

The Basswood Decline Project continues to examine the causes of a decline detected in

the northern hardwood type by the MIMS plots and by the Forest Health Monitoring

(FHM) System. Several plots established in stands with a basswood component are

tracking growth and vigor of basswood trees. In addition, surveys are being done to

determine the insect complex responsible for repeated basswood defoliation in the Lake

States.

A study is underway to evaluate the use of commercially available and native mycorrhizae

at Wyman State Nursery in Manistique, Michigan in cooperation with Michigan

Technological University. The study will assess whether Rhizopogon spp. and native

Laccaria spp. can successfully infect nursery red and jack pine seedlings. The study will

also evaluate a 14-year-old planting of mycorrhizae inoculated seedlings on the Baraga

Forest Unit to see if the fungi are still active.

In cooperation with Michigan State University, a study is under way to look at alternative

methods of regenerating white pine in Michigan. White pine weevil and white pine

blister rust incidence will be assessed in relation to tree growth, site and stand

characteristics in white pine stands in the Upper and Lower Peninsula. Test plots will also

be established to evaluate white pine regeneration methods on abandoned agricultural land,

when underplanted below a hardwood overstory, and in mixed species stands.

For more information contact:

Gerald Thiede, 

State Forester 

P.O. Box 30028 

Lansing, MI 48904 

(517) 373-1275

Forest Health Protection 

Northeastern Area 

USDA Forest Service 

1992 Folwell Avenue 

St. Paul, MN 55108 

(612) 649-5261

Updated: December 1999.......

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