2013 MinnesotaForest Forest Health Health Report 2013 Annual Report Minnesota Department of Natural Resources Division of Forestry Forest Health Unit This document is made available electronically by the Minnesota Legislative Reference Library as part of an ongoing digital archiving project. http://www.leg.state.mn.us/lrl/lrl.asp The Minnesota Department of Natural Resources Forest Health Report was created by the Division of Forestry Forest Health Unit. Cover photos clockwise from upper left: Stormy day on Lake Superior during gypsy moth egg mass survey; map of aerial survey results; bark beetle exit holes; white pine infested by Pityogenes hopkinsi Photo credits: Photos are from DNR forest health staff unless indicated otherwise. Projects were funded in whole or in part through a grant awarded by the USDA Forest Service, Northeastern Area State and Private Forestry. Equal opportunity to participate in and benefit from programs of the Minnesota Department of Natural Resources is available to all individuals regardless of race, color, creed, religion, national origin, sex, marital status, public assistance status, age, sexual orientation, disability, or activity on behalf of a local human-rights commission. Discrimination inquiries should be sent to Minnesota DNR, 500 Lafayette Road, St. Paul, MN 55155-4049 or to the Equal Opportunity Office, Department of the Interior, Washington, D.C. 20240 2 Contents Minnesota County Map ................................................................................................................................................ 5 Division of Forestry Forest Health Staff ........................................................................................................................ 6 Minnesota Forest Resources Summary ........................................................................................................................ 6 Aerial survey results ..................................................................................................................................................... 7 Aerial Survey Plan Map by Quad .................................................................................................................................. 9 2013 Cheat Sheet for Coding Damage Polygons in ArcView .................................................................................. 10 Map of Aerial Survey Results ...................................................................................................................................... 12 ................................................................................................................................................................................ 12 Pest Conditions Report ............................................................................................................................................... 13 Insects ..................................................................................................................................................................... 13 Bark beetles ........................................................................................................................................................... 13 Pityogenes hopkinsi bark beetles .......................................................................................................................... 14 Eastern larch beetle ............................................................................................................................................... 15 Emerald ash borer .................................................................................................................................................. 17 Forest tent caterpillar ............................................................................................................................................ 18 Gypsy moth ............................................................................................................................................................ 20 Jack pine budworm ................................................................................................................................................ 23 Larch casebearer .................................................................................................................................................... 24 .................................................................................................................................................................................... 25 Large aspen tortrix ................................................................................................................................................. 25 .................................................................................................................................................................................... 26 Leaf rollers of aspen ............................................................................................................................................... 26 Spruce budworm .................................................................................................................................................... 27 Two-lined chestnut borer ...................................................................................................................................... 28 Diseases .................................................................................................................................................................. 29 Bur oak blight ......................................................................................................................................................... 29 Butternut canker .................................................................................................................................................... 30 Dutch elm disease .................................................................................................................................................. 31 Eastern dwarf mistletoe ......................................................................................................................................... 32 Oak wilt .................................................................................................................................................................. 33 Scab and black canker of willow ............................................................................................................................ 34 White pine blister rust ........................................................................................................................................... 35 Declines and Abiotic Stressors ................................................................................................................................ 36 Ash decline ............................................................................................................................................................. 36 Aspen decline ......................................................................................................................................................... 37 Blowdown .............................................................................................................................................................. 39 3 Drought .................................................................................................................................................................. 40 Forest Health Program Special Projects ..................................................................................................................... 42 Aspen Decline in Minnesota ................................................................................................................................... 42 Climatic factors influencing outbreaks of eastern larch beetle (Dendroctonus simplex) in Minnesota ................. 46 Determining the forested acres and volume of green ash along the Red River .................................................... 47 Comparing data from Dutch elm disease survey in riparian forests of Red River Valley (final report: 1988) to the FIA results from 2013. ............................................................................................................................................ 49 Red River of the North Project: Ash assessment along both sides of the Red River and up three of its tributaries: Cheyenne, Buffalo, and Red Lake Rivers ............................................................................................. 50 Forest tent caterpillar defoliation: Predicting levels using trends in local observations ....................................... 51 How forest tent caterpillar populations build outbreaks ....................................................................................... 52 Risk-of-spread maps for emerald ash borer ........................................................................................................... 54 Tamarack Health Assessment Report ..................................................................................................................... 57 Tip blight and branch flagging in red pine plantations field study ......................................................................... 61 Storage Conditions Influence Cultural Detection of the Shoot Blight Pathogen Diplodia pinea From