I have a friend who is a highly educated environmental scientist, and she occasionally writes articles for the local newspaper. She has a concern for the health of local trees, and serves on our Town's Conservation Commission I asked if I could share her article. I believe that we are to be stewards of the planet we live on. Actually God gave us dominion over the planet, and all that is in, on, & under it.
Plant Matters
A Few Native Troubled Trees
Native plant advocacy is everywhere these days. Let’s focus on four of our native trees and a couple of the threats they are experiencing. For the purpose of this column, we will only focus on the most recent weather extremes and introduced plant pests.
As our climate rapidly changes, we have more extreme, colder, and wetter springs followed by hotter and drier summers with drought conditions “significant-level-2” for the Northeast region of Massachusetts."
White Ash (Fraxinus americana) is a commercially important tree that is critically endangered and is rapidly declining. Native fungal and insect pests have weakened Ash trees, but the Emerald Ash Borer (EAB) Agrilus planipennis, is causing almost 100% mortality. This insect was introduced in cargo shipped from Asia. Current treatment recommendations vary from: “no method is effective” to “professional tree injection of systemic insecticide”.
Eastern Hemlock (Tsuga canadensis) needs a moist and cool environment with consistent rainfall. Our hot, dry summers are weakening Hemlocks and making them more vulnerable. The woolly adelgid (Adelges tsugae) and the Elongate Hemlock Scale (Fiorinia externa) are native to Japan. The woolly adelgid is causing a major decline of Hemlocks in forests. Systemic insecticides and horticultural oils are used to control these insects in gardens.
American Beech (Fagus grandifolia) is also adversely affected by hot, dry summers because Beech prefers damp and rich soil and temperate conditions. Beech trees are seriously threatened by a recently introduced foliar nematode, Litylenchus crenatae, from Japan. Our recent cold, wet springs, followed by dry, hot summers, provide ideal conditions for this foliar nematode. Beech tree decline has accelerated due to drought and Beech Leaf Disease caused by this foliar nematode. Today, planting Beech trees is not recommended. A systemic nematicide is used to control Beech Tree Disease in gardens.
Sugar Maple (Acer saccharum) is another tree that prefers cool and moist conditions and is threatened by drought. Winter moth (native to Europe) was a severe problem ~10 years ago, but biological controls seem to have lessened the damage. The Asian Longhorn Beetle (Anoplophora glabripennis) was introduced into the Port of New York from Asia and infested trees in Boston and Worcester County. Eradication was successful in Boston. Trees were felled throughout Worcester county and this area continues to be inspected by USDA APHIS (Animal and Plant Health Inspection Service). There may be more natural control methods in the future.
The New England Forestry Foundation released 550 Laricobius nigrinus beetles in Maine to control the woolly adelgid on Hemlocks. There are four wasp species that kill EAB and have been released by APHIS to “biological control partners” in pre-approved areas.
Sources of information: •
APHIS: • https://www.aphis.usda.gov/
• https://www.aphis.usda.gov/plant-pests-diseases/hungry-pests
• UMass Extension Landscape, Nursery and Urban Forest Program • https://www.umass.edu/agriculture-food-environment/landscape
Fini
Ida Wye -Founder of Ida Wye Designs
https://www.idawyelandscapes.com/
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