The Northern Research Station invites you inside the largest forest research organization in the world — the USDA's Forest Service — for conversations with scientists at the forefront of forest research. Forestcast brings you stories, interviews, and special in-depth anthologies of the science that's examining and explaining how forests affect our lives, and how we affect our forests.

To kick things off, a special six-part series on one of the most significant environmental threat to our forests, and the scientists studying and combating these threats. Coming soon!

Produced by the USDA Forest Service Northern Research Station.

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Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

A biological invasion is an enormous increase in population of some kind of living organism. It happens when an organism — like an insect — arrives somewhere beyond its previous range, when it breaks out past its natural barrier, unbalancing the biological order. More than 450 non-native insects have invaded our forests and urban trees since European settlement. In this series, we'll explore four of these insects, and the scientists studying and combating these pests.

In 1957, a British ecologist, Charles S. Elton, gave three radio presentations entitled “Balance and Barrier.” Within a year, he had expanded these ideas into what was to become a bible for practitioners of a burgeoning new science: invasion biology. In a tribute to those broadcasts, this six-part series will explore biological invasions — and their repercussions — in the Midwest and the Northeast.

Related Research:

• “Ecology of Forest Insect Invasions” (2017)
• “A Highly Aggregated Geographical Distribution of Forest Pest Invasions in the USA” (2013)
• “Historical Accumulation of Nonindigenous Forest Pests in the Continental United States” (2011)
• “Economic Impacts of Non-Native Forest Insects in the Continental United States” (2011)
• “The Ecology of Invasions by Animals and Plants” (1958)

Scientists:

• Therese Poland, Project Leader/Research Entomologist, Northern Research Station, Lansing, Michigan
• Sandy Liebhold, Research Entomologist, Northern Research Station, Morgantown, West Virginia
• Robert Haight, Research Forester, Northern Research Station, St. Paul, Minnesota

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-season-1-balance-and-barrier-episode-1-slow-explosion

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

With global trade and travel, organisms are moved around easily and abruptly, causing biological invasions. What’s our best hope to combat these rapidly spreading pests? Sometimes, it’s to do the exact same thing, to start moving around organisms — on purpose — to attack unwanted pests.

This is called ‘biological control.’ It is one of the most cost-efficient and environmentally acceptable long-term approaches for managing invasive species. And, it’s been a crucial component to managing the damage caused by the most destructive forest insect in U.S. history — the emerald ash borer beetle.

Related Research:

• Emerald Ash Borer Biocontrol in Ash Saplings: The Potential for Early Stage Recovery of North American Ash Trees (2017)
• Progress and Challenges of Protecting North American Ash Trees from the Emerald Ash Borer Using Biological Control (2018)
• Progress in the Classical Biological Control of Agrilus Planipennis Fairmaire (Coleoptera: Buprestidae) in North America (2015)
• Buying Time: Preliminary Assessment of Biocontrol in the Recovery of Native Forest Vegetation in the Aftermath of the Invasive Emerald Ash Borer (2017)
• The Role of Biocontrol of Emerald Ash Borer in Protecting Ash Regeneration After Invasion (2017)
• EAB County Detections

Scientists:

• Leah Bauer, Research Entomologist, Northern Research Station, Lansing, Michigan (retired)
• Roy Von Driesche, Entomologist / Conservation Biologist, University of Massachusetts, Amherst, Massachusetts (retired)
• Jian Duan, Research Entomologist, USDA Agricultural Research Service, Newark, Delaware

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-season-1-balance-and-barrier-episode-2-wasps-vs-emerald

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

Insect biological control comes in all shapes and sizes — parasitoids, predators, or pathogens. So, what happens when neither a parasitoid nor a predator are feasible? Well, sometimes we have to turn away from using insects to attack insect pests, and turn to using an even smaller organism, something microscopic: a pathogen — in this case a fungus.

Related Research:

• “Introduction and Establishment of Entomophaga maimaiga, a Fungal Pathogen of Gypsy Moth in Michigan” (1995)
• “Discovery of Entomophaga maimaiga in North American gypsy moth, Lymantria dispar” (1990)

Scientists:

• Andrew "Sandy" Liebhold, Research Entomologist, Northern Research Station, Morgantown, West Virginia
• David Smitley, Professor, Michigan State University, Department of Entomology, East Lansing, Michigan

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-season-1-balance-and-barrier-episode-3-slowing-spongy

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

With no parasitic wasps — like we have for emerald ash borer — and no miracle fungal pathogen — as with gypsy moth — our control options for the nonnative insect threatening Eastern hemlock forests, the hemlock woolly adelgid, have been tricky. Hemlock forests, and the hemlocks in your yard, are paying the price.

Related Research:

• “Hemlock Woolly Adelgid: A Non-Native Pest of Hemlocks in Eastern North America” (2018)
• “Mitochondrial DNA from Hemlock Woolly Adelgid Suggests Cryptic Speciation and Pinpoints the Source of the Introduction to Eastern North America” (2006)
• “Vegetation and Invertebrate Community Response to Eastern Hemlock Decline in Southern New England” (2012)
• “Hemlock Canopy Arthropods Biodiversity On A Threatened Host” (2009)
• “Spring Bird Migration as a Dispersal Mechanism for the Hemlock Woolly Adelgid” (2019)

Scientists:

• Nathan Havill, Research Entomologist, Northern Research Station, Hamden, Connecticut
• Talbot Trotter, Research Ecologist, Northern Research Station, Hamden, Connecticut

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-season-1-balance-and-barrier-episode-4-when-single

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

The Asian longhorned beetle has the makings of a disaster pest poster — a wide possible geographic and climatic range, a number of host trees, and few control options. Lucky for us, it just doesn’t seem to spread far on its own. There are biocontrol and predator options, but nothing is ideal, or especially effective. At this time, there isn’t much we can do other than chop down and chip infested trees.

Related Research:

• “New York's Battle with the Asian Longhorned Beetle” (1997)
• “Mapping of the Asian Longhorned Beetle’s Time to Maturity and Risk to Invasion at Contiguous United States Extent” (2017)
• National ALB Program Overview (2018)

Scientists:

• Melody Keena, Research Entomologist, Northern Research Station, Hamden, Connecticut
• Talbot Trotter, Research Ecologist, Northern Research Station, Hamden, Connecticut

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-season-1-balance-and-barrier-episode-5-hornless-asian

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

In addition to studying and monitoring the non-native insects already here, scientists are monitoring pests that have potential to become problems if they ever do arrive, whether from overseas or from other parts of North America.

Related Research:

• “The Challenge of Modeling and Mapping the Future Distribution and Impact of Invasive Alien Species” (2015)
• “Reproduction and potential range expansion of walnut twig beetle across the Juglandaceae” (2018)
• “Enhanced Mitigation and Rapid Response to Reduce Spread and Impact of Spotted Lanternfly in the United States” (2019)

Scientists:

• Robert Venette, Research Biologist, Northern Research Station, St. Paul, Minnesota
• Melody Keena, Research Entomologist, Northern Research Station, Hamden, Connecticut

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-season-1-balance-and-barrier-episode-6-future-forest

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov

In the 1970s, red spruce was the forest equivalent of a canary in the coal mine, signaling that acid rain was damaging forests and that some species – especially red spruce – were particularly sensitive to this human induced damage. In the course of studying the lingering effects of acid rain, scientists came up with a surprising result – decades later, the canary is feeling much better.

Related Research:

• “The Surprising Recovery of Red Spruce Growth Shows Links to Decreased Acid Deposition and Elevated Temperature” (2018)
• “Quantifying the Legacy of Foliar Winter Injury on Woody Aboveground Carbon Sequestration of Red Spruce Trees” (2013)
• “Calcium Addition at the Hubbard Brook Experimental Forest Increases the Capacity for Stress Tolerance and Carbon Capture in Red Spruce (Picea rubens) Trees During the Cold Season” (2011)
• “The Isolated Red Spruce Communities of Virginia and West Virginia” (2010)
• “Acid Rain Impacts on Calcium Nutrition and Forest Health” (1999)
• "Ecology and Decline of Red Spruce in the Eastern United States" (1992)

Scientists:

• Mary Beth Adams, Research Soil Scientist, Morgantown, West Virginia
• Paul Schaberg, Research Plant Physiologist, Burlington, Vermont

Produced by the USDA Forest Service Northern Research Station.

Want more information? Visit us at https://www.fs.usda.gov/research/nrs/products/multimedia/podcasts/forestcast-special-episode-window-resurgence-red-spruce

Questions or ideas for the show? Connect with Jon at: jonathan.yales@usda.gov