Got Nature? Blog

Agricultural & Natural Resources (ANR) Newsletter: On May 5, Natural Resources professionals gathered at the Davis Purdue Agricultural Center (DPAC) in Farmland, Indiana, for a forestry and wildlife management training led by Purdue Forestry and Natural Resources’ Brian MacGowan, wildlife extension specialist and extension coordinator; Don Carlson, forester; Jarred Brooke, wildlife extension specialist; and Jessica Outcalt, natural resources training specialist. The program combined classroom updates with field-based learning focused on active land stewardship, habitat management and conservation planning.

During the field tour of DPAC and Herrmann Properties, participants explored topics including native warm-season grass management using prescribed fire, Sericea lespedeza control in native grass plantings, prairie restoration, young forest management, and oak forest management for multiple objectives. Don Carlson discussed the history and management goals of DPAC, emphasizing how tree spacing, mowing and the use of crop and nurse trees influence tree establishment and growth. Jarred Brooke highlighted challenges such as rabbit damage to young trees and invasive species management. Participants learned key wildlife habitat principles, including a practical guideline for quail habitat: If a baseball tossed into the grass rolls, the habitat structure is suitable for quail; if it does not roll, the vegetation is too dense. The day concluded with updates on the NR Training Hub, prescribed fire and evaluation efforts.

If you’re interested in bringing a program like this to your area, we’d love to hear from you, submit a request at fnrextension@purdue.edu.

Emily Kring, Extension Educator
Agriculture & Natural Resources, Purdue Extension Jay County

Jessica Outcalt, Natural Resources Training Specialist
Purdue Extension – Forestry & Natural Resources

Resources:
Natural Resources Training Hub
Explore the Rich World of Oaks with Purdue FNR Extension & Partners
Forestry for the Birds Pocket Guide, The Nature Conservancy
Natural Resources Conservation Service (NRCS)
Community Planning for Agriculture and Natural Resources: A Guide for Local Government, The Education Store, Purdue Extension’s research center
The Nature of Teaching
Help the Hellbender
Let the Sun Shine in Indiana
Community Development, Purdue Extension
Subscribe – Purdue Extension-FNR YouTube Channel, find natural resources and much more in playlists.

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Most of us have probably heard or seen a lot about pollinators in the media recently. The reason why is that pollinators are really, really important. We simply can’t live without them. Researchers estimate that one out of every three bites of food we eat is made possible by pollinators. More than 100 food crops in the U.S. depend on pollinators, including almost all fruit and grain crops.

There are many different types of pollinators including native bees, butterflies and moths, beetles, flies, wasps, and of course hummingbirds. But perhaps one of the more interesting pollinators is the Monarch. Millions of Monarchs congregate in a relative small area in Mexico each winter. In March they start their journey north which has occurred over several generations. Unfortunately, the number of Monarchs counted in overwintering colonies has declined over the past 25 years.

In response, many states including Indiana have developed a state Monarch Conservation Plan. With input from many stakeholders over several years, the Indiana Monarch Conservation Plan was released in December 2020. One goal of the plan was to create an online resource that would act as a clearinghouse for Indiana monarch and pollinator conservation data, research, best management practices (BMPs), and events. I invite you to visit the Indiana Monarch and Pollinator Conservation Hub at indianawildlife.org/monarchs.

You might be asking yourself, ‘Why is a wildlife specialist writing about pollinators?’ It turns out that quality habitat for wildlife is often quality habitat for pollinators. The diversity of wildflowers and structure that native grasslands, trees and shrubs benefit them all. Trees such as eastern redbud and Ohio buckeye provide early nectar sources. Native grasslands that have a diverse mixture of wildflowers provide food, bare ground, and structure desirable for a wide variety of pollinators.

Resources
Protecting Pollinators: Why Should We Care About Pollinators?, The Education Store, Purdue Extension resource center
Ask The Expert: What’s Buzzing or Not Buzzing About Pollinators , Purdue Extension – Forestry & Natural Resources (FNR) YouTube Channel
Purdue Pollinator Protection publication series, Purdue Extension Entomology
Is My Urban Garden Helping Native Pollinators?, Purdue Landscape Report
Indiana Monarch & Pollinator Conservation Hub, Indiana Wildlife Federation
Monarch Watch, University of Kansas
100 Plants to Feed the Monarch/Other Resources Available, Xerxes Society for Invertebrate Conservation

Brian MacGowan, Wildlife Extension Specialist & Extension Coordinator
Purdue Department of Forestry and Natural Resources

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Spotted lanternfly (SLF) is a major pest of concern across most of the United States. Spotted lanternfly (SLF) is an invasive planthopper native to China that was first detected in the United States in Pennsylvania in 2014. SLF feeds on over 70+ plant species including fruit, ornamental and woody trees with tree-of-heaven as its preferred host. Spotted lanternfly is a hitchhiker and can easily be moved long distances through human assisted movement.

Know the Primary Host: Tree -of-Heaven
Tree of heaven (TOH) is the preferred host for the spotted lanternfly (SLF).  The ability to identify TOH will be critical to monitoring the spread of this invasive pest as the 4th-stage nymphs and adult spotted lantern-flies show a strong preference for TOH.

Report a Sighting
If you suspect you’ve seen a spotted lanternfly, please take the following steps:

• Take a picture and note your location.
• If you can, collect a sample of the insect by catching it and placing it in a freezer. You can use any container available as long as it has a tight seal (like a water bottle) so that the spotted lanternfly can’t escape.
• Report your sighting through one of the following channels:
  Email: DEPP@dnr.in.gov
  Online: eddmaps.org or ReportINvasive
  Phone: 1-866-663-9684

Help Stop the Spread
Everyone can play a role in slowing the spread of spotted lanternfly:

• Inspect vehicles, trailers and outdoor equipment for spotted lanternfly eggs, nymphs, and adults before driving or moving to a new location.
• Avoid moving firewood, as it can transport SLF and other invasive pests.
• Stay informed by subscribing to trusted resources like the up to date with the latest newsletters: Purdue Landscape Report and Indiana Department of Natural Resources – Entomology & Plant Pathology Weekly Review E-newsletter.
• Follow updates and management tips on social media by connecting with ReportINvasive on Facebook (@reportINvasive) and Indiana Department of Natural Resources, which shared information acrossa Facebook, Twitter and Instagram (@INdnrinvasive).

Spread Awareness
Share your spotted lanternfly knowledge with others! Share about SLF with neighbors, colleagues and your communit to help protect Indiana’s natural and agricultural resources.

Resources:
Spotted Lanternfly, Indiana Department of Natural Resources Entomology
Spotted Lanternfly is on the Move!, Purde Landscape Report
Spotted Lanternfly Egg Hatch is Here, Purdue Landscape Report
Spotted Lanternfly Found in Indiana, Purdue Landscape Report
Invasive plants: impact on environment and people, The Education Store, Purdue Extension’s resource center
Woodland Management Moment: Invasive Species Control Process, Video, Purdue Extension – Forestry and Natural Resources YouTube Channel
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Report Invasive

Diana Evans, Extension and Web Communication Specialist
Purdue University Department of Forestry and Natural Resources

Purdue Extension – Entomology

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With storm season just around the corner, one topic of concern on many minds is damage to and from trees. Depending on the intensity of the storms and the condition of the trees, damage from high winds, heavy rainfall, and lightning can be quite severe. Cracked or broken branches, stem failure, and root failure are some of the main concerns, but also the risk and liability of damage to people and property.

If your tree is damaged, there are some steps to deal with the situation. First and foremost, consider the safety of yourself and others around you. Inspect the tree from a distance first looking for the following:

• Heaving of the ground indicating potential root failure
• Damage to limbs and/or the trunk of the tree
• Hanging branches can fall to the ground resulting in injury or death
• Be aware of utility and power lines. Trees can become charged by coming in contact with live wires. All utility lines should be considered energized and dangerous.

If you find your trees damaged from a storm hiring an International Society of Arboriculture (ISA) Certified Arborist to perform a risk assessment will help guide your decision of how to manage your tree. To find an arborist near you and verify credentials use the link at Find an Arborist, Trees are Good, International Society of Arboriculture (ISA). For more information, you can also view Trees and Storms: Understanding Damage, Risk and Recovery, an informational Got Nature? Blog article from Purdue Extension.

Resources:
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
Caring for storm-damaged trees/How to Acidify Soil in the Yard – In the Grow, Purdue Extension
Tree Risk Management – Got Nature? Blog, Purdue Extension – FNR
Why Is My Tree Dying? – Got Nature? Blog, Purdue Extension – Forestry and Natural Resources (FNR)
Mechanical Damage to Trees: Mowing and Maintenance Equipment – Got Nature? Blog, Purdue Extension – FNR
Trees and Electric Lines – The Education Store
Planting Your Tree Part 1: Choosing Your Tree, video, Purdue Extension – FNR YouTube Channel
Tree Installation: Process and Practices, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – FNR
Subscribe – Purdue Extension-FNR YouTube Channel

Lindsey Purcell, Executive Director
Indiana Arborist Association

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One of the most dangerous pests of trees is humans, especially humans with equipment. Lawn mowers and weed trimmers can cause injuries that create a hazard when an injury leads to tree disease or death. This blog explains why the damage is so dangerous and suggests ways to protect your trees.

Defended by Bark
The site of injury is usually the root flare: the area where the tree meets the turf and gets in the path of the mower or trimmer. The root flare, like the rest of the trunk, is protected by bark, which guards a very important plant transport system just behind the woody bark layer. Specialized tubes move nutrients and water between the roots and leaves to keep the tree alive. Any damage to this transport system can affect tree health and the tree could die.

The bark layer can vary in thickness on different tree species. It can be more than an inch in thickness or less than 1/16 of an inch on young, smooth-barked trees such as maples and birches. This isn’t much protection against string trimmers and mowing equipment, especially on young, newly planted trees.

Damage Done
Any damage to or removal of the bark and the transport system can cause problems for a tree. Even when a tree tries to recover from a wound, leaves and branches often decline and die back, because food and water pathways were destroyed. Although a large wound is generally more serious than a smaller one, repetitive wounding adds up to greater trouble for the tree. If the damage extends completely around the base of the tree (a situation called girdling), the tree ultimately dies.

All tree wounds are serious when it comes to tree health. No matter what size the wound is, the damage done is irreversible. The tree must devote a great deal of energy and many resources into trying to seal off the damaged area to prevent further complications. The wounded area is an opening for wood-rotting organisms and decay fungi to enter and cause further damage. These microorganisms often attack the injured bark and invade adjacent healthy tissue, greatly enlarging the wound and extending the damage. Trees can be completely girdled from pathogen attack following injuries.

Fungi that are active on the wound surface can also deteriorate the structure of the woody tissues beneath, decaying and weakening the tree. This weakened, structurally unsound tree may eventually die and become a hazard to people around it.

Preventing Problems
Newly planted, young trees need our help to become established in the landscape. They are the trees most commonly and seriously affected by maintenance equipment.

However, injury to these trees can be avoided easily and at very low cost if you follow one or more of these suggestions.

1. Physically remove turf or prevent grass and weeds from growing at the base of the tree. This lowtech solution can eliminate a potentially serious problem.
2. Spray herbicides to eliminate vegetation around the base of the tree to decrease mowing maintenance costs. Be sure to use care when applying herbicides around trees. Carefully follow label directions.
3. Add a mulch ring, when possible, to help reduce the competition for water and nutrients. Mulch or other ground coverings reduce mowing requirements in the landscape.
4. Add a 2˝ to 3˝ layer of mulch on the root zone of the tree to provide an attractive and healthy environment for the tree to grow. This also provides a visual cue to keep equipment away from the tree.
5. Add trunk guards or similar devices to give the tree additional protection. White, expanding tree guards can help help trees withstand equipment contact and also can help to reduce winter injury.

Trees are a valuable asset to your property and are important to our environment. Every tree contributes to the urban forest and improves air and water quality in your neighborhood. Protect and preserve these growing assets by keeping mowing and weed-trimming equipment away from tree trunks. The damage lasts and it cannot be undone. Don’t create a hazard!

Resources:
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Tree Pruning Essentials Video, Purdue Extension YouTube Channel
Tree Defect Identification, The Education Store, Purdue Education’s resource center
Why Is My Tree Dying?, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources (FNR)
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – FNR
Surface Root Syndrome, The Education Store
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
Trees and Storms: Understanding Damage, Risk and Recovery – Got Nature? Blog, Purdue Extension – FNR
Report INvasive, Purdue Extension
Indiana Invasive Species Council
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel (Invasive White Mulberry, Siberian Elm, Tree of Heaven)
Fifty Common Trees of Indiana
Native Trees of the Midwest, Purdue University Press
Subscribe – Purdue Extension-FNR YouTube Channel

Lindsey Purcell, Executive Director
Indiana Arborist Association

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Join Purdue Extension forester Lenny Farlee in this episode of “A Woodland Management Moment” as he explores the considerations for growing high timber-quality black walnut on purpose. Learn about what black walnut requires to grow well, its visual characteristics and the timeline of this plant in openings. Watch the video to discover some of the management strategies you can use gradually develop these black walnut stems for timber markets.

 

If you have any questions regarding trees, forests, wildlife, wood products, or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
A Woodland Management Moment, Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
The Nature of Oaks Webinar, Purdue Extension-FNR YouTube Channel, Shared from Indiana Forestry & Woodland Owners Association
Conservation Tree Planting: Steps to Success, Purdue Extension – FNR YouTube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel
Investing in Indiana Woodlands, The Education Store
Woodland Stewardship for Landowners Video Series, Playlist, Indiana Department of Natural Resources YouTube Channel
Ask an Expert: Tree Selection and Planting, Purdue Extension – FNR YouTube Channel
Forest Improvement Handbook, The Education Store
Find an Indiana Professional Forester, Indiana Forestry & Woodland Owners Association (IFWOA)
Purdue Arboretum Explorer

Lenny Farlee, Extension Forester
Hardwood Tree Improvement and Regeneration Center
Purdue Department of Forestry & Natural Resources

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Rooted in Research, USDA Forest Service: Non-native species are increasingly shaping forests across the eastern United States. While many introduced species coexist without major disruption, some become invasive: damaging ecosystems, reducing biodiversity and impacting the economic value forests provide. Over the past decade, the extent of forest land affected by invasive species has continued to grow, making management more complex and costly.

To address these challenges, the USDA Forest Service Research and Development team is hosting a six-part webinar series focused on invasive species in eastern forests. This series brings together leading scientists to share research-backed management strategies and explore the ecological and economic impacts of invasive species across the region.

These are virtual webinars that will be held on select Tuesdays and Thursdays in May. Each webinar will be ~60 minutes and start at 2:00 PM Eastern time. All events are open to anyone interested in forest health, conservation and management!

Here is the schedule for the upcoming webinars:

1. May 5 – Invasive Species in Eastern Forests: Extent, Impact, and Response
2. May 7 – Managing Invasive Plants: Understanding Rapid Adaptation and Strategies for Control 
3. May 12 – Hemlock Woolly Adelgid: Protecting Hemlocks with Silviculture and Biocontrol 
4. May 14 – Management Solutions for Emerald Ash Borer 
5. May 19 – Tracking Spongy Moth Defoliations and the Economics of Slowing the Spread 
6. May 21 – Emerging Threats: Asian Needle Ant and Beech Leaf Disease 

Participants must register for each webinar individually, visit to Research & Development Presents: Invasive Species in Eastern Forests learn more and sign up.

Forests play a critical role in supporting biodiversity, protecting water resources, and contributing to local and regional economies. As invasive species continue to spread, understanding how to manage and mitigate their impacts is more important than ever. This webinar series provides an opportunity to learn directly from experts working at the forefront of forest research.

To subscribe to the newsletter, visit Sign Up for Rooted in Research.

Learn and read more about the research done by the USDA Forest Service by exploring the Northern Research Station and Southern Research Station.

More Resources
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Invasive Species Playlist, Playlist, Purdue Extension – FNR YouTube Channel
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Report Invasive, Purdue Extension
Episode 11 – Exploring the challenges of Invasive Species, Habitat University-Natural Resource University
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – FNR
Invasive plants: impact on environment and people, The Education Store
New Hope for Fighting Ash Borer, Got Nature? Purdue Extension-FNR
Invasive Pest Species: Tools for Staging and Managing EAB in the Urban Forest, Got Nature?
Emerald Ash Borer, Purdue Extension-Entomology
Emerald Ash Borer Tools & Resources – Purdue Extension Entomology

U.S. Department of Agriculture (USDA) Forest Service, Research & Development

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Spring is one of the best times to identify trees and shrubs in Indiana. As buds break and flowers emerge, many species reveal distinctive traits that make identification easier and more enjoyable. In this collection of ID That Tree videos, Purdue Extension Forester Lenny Farlee highlights a variety of native trees and shrubs from eye-catching flowering species to lesser-known woodland plants. Whether you’re a student, landowner or simply enjoy exploring the outdoors, these videos offer a quick and accessible way to build your tree identification skills this spring.

Explore the Spring Bloom Edition videos, starting with Umbrella Magnolia:

 

Continue building your identification skills with these additional ID That Tree: Spring Bloom Edition videos:

Trees:

• ID That Tree Spring Bloom Edition: American Plum
• ID That Tree Spring Bloom: Flowering Dogwood
• ID That Tree Spring Bloom: Ohio Buckeye
• ID That Tree Spring Bloom: PawPaw
• ID That Tree Spring Bloom: Redbud
• ID That Tree Spring Bloom: Sassafras
• ID That Tree Spring Bloom: Serviceberry
• ID That Tree Spring Bloom: Yellowwood

Shrubs & Small Trees:

• ID That Tree Spring Bloom: American Hazelnut
• ID That Tree Spring Bloom: Bladdernut
• ID That Tree Spring Bloom: Blackhaw
• ID That Tree Spring Bloom: Hawthorn
• ID That Tree Spring Bloom: Mapleleaf Viburnum
• ID That Tree Spring Bloom: Spicebush in Flower

Check out more spring Got Nature? blog posts:
As the Spring Wildlflowers Emerge, so do the Woodland Invaders
Spring Tree Preparations
Spring Season is Mole Season
Question: Anything I Can Do About An Increase Of Snakes Around The House This Spring?
Protecting Spring Plants From Wildlife Damage Using Repellents
It’s Timberdoodle Time!
Putting a Little Wildlife in Your Backyard this Spring, publication in The Education Store, Purdue Extension’s resource center

If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, Purdue Extension – FNR is here to help. Visit our Ask an Expert  webpage to connect with a Purdue Extension specialist.

Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources (FNR> Youtube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR Youtube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
New Tool for Helping Landowners to Help Declining Birds, Forestry for the Birds, Got Nature? Blog, Purdue Extension – FNR
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Purdue Arboretum Explorer
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel
Fifty Common Trees of Indiana, Purdue Extension – FNR
ReportINvasive, Purdue College of Agriculture – Entomology
Cooperative Invasive Species Management Area (CISMA)
Report Invasive, Purdue College of Agriculture – Entomology
Professional Forester, Indiana Forestry Woodland Owners Association (IFWOA)
District Forester, Indiana Department of Natural Resources, 10+ acres
Find an Arborist, International Society of Arboriculture

Diana Evans, Extension & Web Communications Specialist
Purdue University Department of Forestry and Natural Resources

Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources

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Purdue Landscape Report: Each of us utilize mobile devices and daily consume services that require fiber and other utility infrastructure. Necessary utility work along roadways often leaves sunken trenches, compacted soil for lawns that are uneven or stripped of vegetation. If damage is significant, check with the utility provider, as many companies have restoration policies or reimbursement options for affected homeowners. However, subcontractors and varying degrees of action by utilities can make this a frustrating process.

But a few timely steps can speed recovery and simplify the process rather than dealing with later weed overgrowth or washing overtime. Begin by removing rocks, excess gravel, and construction debris. Loosen the sides of ruts or where excess soil remains beside a trench with a rake or shovel to level out and improve water infiltration and root development. If the area has settled or ruts are present after a period of time, regrade to match the surrounding lawn and ensure proper drainage away from the roadway and sidewalks. Use extra caution when these areas are collocated with drainage or susceptible to water over wash as your work can be whisked away. In some cases, ignored sunken trenches and ruts can be back filled with highly deteriorated mulch to help bring back life to the soil if one has patience to let time continue to run its course and seed later into the mellowed, high organic matter soil.

Next, incorporate quality topsoil or compost to rebuild soil structure and fertility.

Choose a grass seed mix appropriate for your region and light conditions and apply it evenly over the prepared area. Lightly rake the seed into the soil and cover with straw mulch to reduce erosion and conserve moisture. Keep the area consistently moist with light, frequent watering until seedlings are well established, typically 2–3 weeks depending on weather. If the season is not fit for seeding grass (i.e. July) try seeding a temporary cover crop like buckwheat that will attract pollinators and give short term cover while choking out weeds.

For larger or highly visible areas, sod can provide an instant fix, though it is both expensive and requires careful watering to root successfully. Once new grass reaches 3–4 inches, begin mowing and apply a light fertilizer application to encourage growth.

In summary, it depends on the time frame and the urgency you have to fix a recently created problem based on its location. For problem areas that have existed over time where weed growth has already occurred, using composted mulch to fill sunken trenches or ruts may be the easiest, while using mowing to manage weeds during summer and seed after lighly working surface more towards late summer or early fall.

View the original article on the Purdue Landscape Report website: Roadside Rehab: Rebuilding Soil and Cover After Utility Damage.

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
Trees and Storms: Understanding Damage, Risk and Recovery – Got Nature? Blog, Purdue Extension – FNR
Caring for storm-damaged trees/How to Acidify Soil in the Yard – In the Grow, Purdue Extension
Why Is My Tree Dying? – Got Nature? Blog, Purdue Extension – Forestry and Natural Resources (FNR)
Tree Risk Management – Got Nature? Blog, Purdue Extension – FNR
Mechanical Damage to Trees: Mowing and Maintenance Equipment – Got Nature? Blog, Purdue Extension – FNR
Trees and Electric Lines – The Education Store
Tree Defect Identification, The Education Store
Planting Your Tree Part 1: Choosing Your Tree, video, Purdue Extension – FNR YouTube Channel
Tree Installation, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – FNR
Ask an Expert: Tree Selection and Planting, Purdue Extension – FNR YouTube Channel
Tree Pruning Essentials, Purdue Extension – FNR YouTube Channel
Subscribe – Purdue Extension-FNR YouTube Channel

Mark Evans, Extension Educator/Plant & Soil Science, Elkhart County
Purdue Extension – Agriculture & Natural Resources (ANR)

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Walk through many forests in Indiana today, and you might not notice what is missing until you look up. Ash trees, once a common part of these woodlands, have rapidly disappeared due to the invasive emerald ash borer. Since its arrival in the early 2000’s, this small beetle has killed millions of ash trees across the state (Figure 1).

But what happens after ash trees are gone? Do new trees grow in their place, or do forests begin to change in unexpected ways?

To answer these questions, researchers revisited long-term forest monitoring plots across Indiana that were first established in the 1990s, before emerald ash borer was present. By comparing forest conditions before and after widespread ash mortality, we can begin to understand how these ecosystems are responding to one of the most destructive invasive forest pests in North America.

Even though young ash trees are still present in many forests, their numbers are dropping quickly (Figure 2). In some areas, ash seedlings have declined by more than 70 percent over the past decade. While a few saplings remain, very few are surviving long enough to replace the large trees that have been lost.

This suggests that ash is unlikely to return as a major component of Indiana forests anytime soon. As the remaining seeds in the soil are used up and fewer young trees survive, ash may become a much rarer species on the landscape.

As ash declines, other plant species are filling the gaps, but not always in the way we might expect.

Instead of fast-growing canopy trees taking over, many forests are becoming dominated by shade-tolerant species that thrive in low-light conditions. Native plants like spicebush and pawpaw are increasing in abundance, often forming dense layers in the understory. These species can make it difficult for other trees to establish and grow.

Sugar maple, another shade-tolerant species, remains common as seedlings but is not always successfully growing into larger trees. This creates a bottleneck where young trees are present, but few make it into the next stage of forest development.

At the same time, invasive plants are becoming more common in many forests following ash loss. Species such as bush honeysuckle and multiflora rose are increasing, especially in areas where ash trees have died.

These invasive plants can outcompete native vegetation, further limiting the ability of forests to regenerate diverse tree communities. Once established, they often persist and spread, creating additional challenges for forest management.

When large trees die, we might expect more sunlight to reach the forest floor, helping new trees grow. However, in many Indiana forests, the loss of ash is creating only small openings in the canopy rather than large gaps.

These smaller gaps favor shade-tolerant plants rather than species that need full sunlight to thrive. As a result, forests are gradually shifting toward communities dominated by shrubs and slow-growing, shade-adapted trees.

Ecologists often refer to this process as mesophication, a transition toward cooler, shadier, and more moisture-loving forest conditions. Over time, this can lead to forests that are more uniform and less diverse.

The loss of ash is more than just the disappearance of a single group of trees: it is part of a broader pattern of change driven by invasive species, altered disturbance patterns, and shifting forest conditions.

Without intervention, many forests may continue to develop dense understories dominated by a small number of species, including invasive plants. This can reduce tree diversity, limit wildlife habitat, and alter how forests function over time.

While forests are resilient and will continue to grow and change, they may look very different from those of the past.

Landowners, land managers, and the public all play a role in supporting healthy forests. Monitoring for invasive species, promoting a diversity of native trees, and managing dense understory growth can help improve forest regeneration.

As research continues, understanding how forests respond to the loss of species like ash will be critical for guiding conservation and management efforts in the years ahead.

Resources:
Emerald Ash Borer, Purdue Extension-Entomology
Emerald Ash Borer, Animal and Plant Health Inspection Service (USDA)
Emerald Ash Borer Invasion of North America: History, Biology, Ecology, Impacts, and Management, Daniel A. Herms, Deborah G. McCullough, 2014, Annual Review Entomology.
New Hope for Fighting Ash Borer, Got Nature? Purdue Extension- Forestry and Natural Resources (FNR)
Emerald Ash Borer Tools & Resources – Purdue Extension Entomology
Invasive Pest Species: Tools for Staging and Managing EAB in the Urban Forest, Got Nature? Blog, Purdue Extension – FNR
Now is the Time to Control Non-Native Bush Honeysuckle, Got Nature? Blog, Purdue Extension – FNR
What are Invasives Species and Why Should I Care?, Got Nature? Blog, Purdue Extension – FNR
ID That Tree: Invasive Multiflora Rose, Purdue Extension – FNR YouTube Channel
Invasive Species, Purdue Extension – FNR YouTube Channel
Report INvasive, Purdue Extension
The GLEDN Phone App – Great Lakes Early Detection Network
EDDMapS, Early Detection and Distribution Mapping System
Cooperative Invasive Species Management Area (CISMA)
Find an Arborist, International Society of Arboriculture
Professional Forester, Indiana Forestry Woodland Owners Association (IFWOA)
District Forester, Indiana Department of Natural Resources, 10+ acres
Tree Planting Part 2: Planting a Tree, Purdue Extension – FNR YouTube Channel
Conservation Tree Planting: Steps to Success, Purdue Extension – FNR YouTube Channel
Hardwood Tree Improvement and Regeneration Center (HTIRC)
Tree Risk Management – Got Nature? Blog, Purdue Extension – FNR
Subscribe – Purdue Extension-FNR YouTube Channel

Thaddeus Swart, Graduate Research Assistant
Purdue Department of Forestry & Natural Resources

Faculty Advisors:
Dr. Mike Jenkins, Forestry & Natural Resources Professor
Purdue Department of Forestry & Natural Resources

Dr. Mike Suanders, Professor of Ecology and Natural Resources
Purdue Department of Forestry & Natural Resources

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