Purdue University - Extension - Forestry and Natural Resources
In 2023, our FNR Extension website featured stories on topics ranging from wildlife identification, concerns in forestry, urban forestry issues and aquaculture how-to guides. Here are the top stories our FNR Extension readers were interested in last year from archival favorites to new publications on our Got Nature! blog.

1 – Tree Wounds and Healing — Trees are incredible survivors in spite of the challenges from pests of all kinds, including us! They are vulnerable to injuries such as mechanical wounds from lawn equipment, vehicles and ice. Pruning results in an intentional wound which is of importance to consider. Tree owners and managers need to prune trees to maintain aesthetic characteristics, remove infected limbs, reduce risk, or improve structural stability. Proper pruning practice and understanding tree wounds can minimize the impact of creating wounds on trees.
2 – Question: Can Tree Roots Cause Damage to a Home’s Foundation? — A reader asked this question regarding a pin oak tree that is within 10 feet of their house after receiving A certified arborist took a look at it and said that he would like to use an Air Knife to expose the roots near the foundation (a walkout basement) to determine if the roots are causing damage and/or need to be pruned, or whether the tree needs to be removed since it is situated too close to the house.
3 – Question: I Saw A Squirrel with No Fur on Its Neck, Both Backside and Underneath. What Is This? — People can be taken aback by the sight of squirrels missing hair. Sightings of partially furred squirrels is not unusual with warmer temperatures experienced through the winter. Like many wildlife issues, the cause of hair loss in squirrels is not easy to answer and often results in more questions than answers. In most situations, hair loss does not impact populations of squirrels.
4 – Be on the Watch for EHD in Deer — In August 2019, residents were warned to be on the watch for Epizootic Hemorrhagic Diseases (EHD) in deer after a white-tailed deer in Clarke County, Indiana tested positive for Epizootic Hemorrhagic Disease (EHD), and potential EHD cases had been reported in 26 other Indiana counties. Here are a few things you should know about how EHD, how to spot it, and how to report it.
5 – Question: Are Carpenter Ants Harmful to My Tree? — Carpenter ants are very common inside trees, especially on larger, mature trees that are hollow with cavities. They nest in rotted, decayed wood, although some nests may extend into sound heartwood in the center of the tree. Carpenter ant presence is an indication of rotting wood, and infested trees should be checked to determine whether the rot has weakened the tree enough that it has become a risk of failure.
6 – Question: Why Are There So Many Acorns This Year? — If you have ever noticed acorns so numerous that you could not take a step without crushing several, you may be asking the question, “why are there so many acorns?” Some answers to this question can be found in the physiology and ecology of trees and their relationship to wildlife.
7 – It Is A Salamander. No, It Is a Lizard. Are They Different? — Salamanders are often mistaken for lizards, but the two groups are very different. Learn the differences between lizards and salamanders, how to identify each and more.
8 – Question: Blue Spruce is Dying, What Can I Do? — A reader sent in a question asking about a 40-year old spruce which is dying in the middle. There was a concern about Rhizosphaera needle cast as well as questions about fungus control sprays or alternative fungicide treatments.
9 – Slime Flux of Trees — Slime flux (also known as wet wood) is a dark, foul-smelling and unsightly seepage of sap from tree trunks. The disease is not usually a serious problem but the appearance can be alarming. Learn about the symptoms of slime flux, diagnosis and prevention measure.
10 – What Do Trees Do In the Winter? — Do they freeze up like unprotected water pipes? Or burst when it gets below freezing? Yes, the below-ground parts of a tree are kept insulated by mulch, soil and a layer of snow, and that is important to survival, but the exposed parts of a tree are not protected.
To see the full article, please visit FNR News & Stories.
Resources
Tree Pruning: What Do Trees Think?, The Education Store
Mechanical Damage to Trees: Mowing and Maintenance Equipment, The Education Store
Surface Root Syndrome, The Education Store, Purdue Extension resource center
The Nature of Teaching: Trees of the Midwest, The Education Store
Diseases in Hardwood Tree Plantings , The Education Store, Purdue Extension’s resource center
Iron Chlorosis of Trees and Shrubs, The Education Store
Purdue Landscape Report, Website
Winterize Your Trees, The Education Store, Purdue Extension resource center
Tree Defect Identification, The Education Store
Forest/Timber, Playlist, Purdue Extension – Forestry and Natural Resources YouTube channel
Urban Forestry, Purdue Extension – FNR playlist
Wendy Mayer, FNR Communications Coordinator
Purdue University Department of Forestry and Natural Resources
Videos on the Purdue Forestry and Natural Resources Extension YouTube channel received more than 213,000 views in 2023. The Top 50 videos included 47 editions of ID That Tree, an informational series by Purdue Extension forester Lenny Farlee, as well as a webinar by Farlee on How to Identify Trees in Indiana. The remaining two videos in the Top 50 were an instructional video about a common urban tree planting problem by former Purdue Extension urban forester Lindsey Purcell, and a video about the use of prescribed fire on the Hardwood Ecosystem Experiment.
Below we will count down the 10 most viewed Purdue FNR Extension videos of 2023 with a few bonus videos sure to shoot up the list in future years.
Our most viewed video in 2023 was ID That Tree: Black Walnut with a whopping 18,156 views. This video has been seen more than 28,000 times since its debut in September of 2020.
1 – ID That Tree: Black Walnut — Learn the identifying characteristics of the black walnut tree, also known as the American black walnut or eastern black walnut, including pairs of leaflets running down each stem, long running ridges on the bark, and round nuts that have a very strong exterior. This sun-loving tree also needs high quality soil.
Our second most viewed video is ID That Tree: American Elm. This video, which debuted in June 2020, was watched 16,779 times in 2023, and has been viewed 33,456 times overall.
2 – ID That Tree: American Elm — In this tree identification series you will see how American elm leaves have jagged edges with a large tooth and then smaller teeth like edges on top of it. Find out why these trees are not as easy to find as they used to be.
Number three on our most viewed list is ID That Tree: Black Oak. This video, which debuted in March 2021, was seen 5,773 times in 2023.
3 – ID That Tree: Black Oak — In this episode of ID That Tree, we continue to get to know the oak groups, this time focusing on the black oak species. Deep sinuses on the leaves and shinier coat, a dark blocky bark and acorns with loose shingle-like plates on the cap are some key identifiers to separate it from the red oak and others.
Number four on the most viewed videos list was ID That Tree: Invasive White Mulberry. This video, which debuted in September 2021, was seen 5,197 times in 2023.
4 – ID That Tree: Invasive White Mulberry — On this episode of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to a non-native invasive tree that is widespread across the state, white mulberry. Key identifying characteristics to separate it from its native cousin red mulberry are shiny variable leaves and where the species grows, near fence rows, hedgerows and other waste areas. The red mulberry has larger leaves that are duller in color with a sandpapery texture, and the species is often found in the forest understory.
Fifth on our countdown of top videos of 2023 is ID That Tree: Pignut Hickory. This video, which debuted in March 2022, was seen 4,569 times in 2023.
5 – ID That Tree: Pignut Hickory — In this edition of ID That Tree, meet another member of the hickory family that can found in upland areas, the pignut hickory. This species is identifiable by its five-leaflet compound leaves, its smooth round nut and partially open husk.
Number six on our list of top videos for the year is ID That Tree: Northern Catalpa. This video, which debuted in August 2021, was watched 4,489 times in 2023.
6 – ID That Tree: Northern Catalpa – On this episode of ID That Tree, meet the Northern Catalpa, native to southern Indiana along the Ohio River bottoms. This species, which provides rot resistant wood great for outdoor usage, features beautiful flower clusters in early summer, huge heart shaped leaves in whirled formation, and long bean-like fruit pods.
Number seven on our Purdue FNR Extension most viewed list is ID That Tree: Sassafras. This video, which debuted in July 2020, was seen 4,481 times in 2023. Graduate student Olivia Bingham is researching sassafras wilt in Indiana and needs your help with possible sightings across the state.
7 – ID That Tree: Sassafras — Join Purdue Extension forester Lenny Farlee as he introduces you to the Sassafras in this edition of ID That Tree. The Sassafras is well known for the tea made from its bark and also for having a variety of shaped leaves from zero to three lobes.
Eighth on our 2023 most watched videos list is ID That Tree: Red Pine. This video, which debuted in February 2022, was seen 4,470 times in 2023.
8 – ID That Tree: Red Pine — This week on ID That Tree, Purdue Extension forester Lenny Farlee introduces you to a non-native conifer that can be found throughout the state, the Red Pine. This species, which enjoys sandy soil, is identifiable by its small, egg-shaped cones, as well as tufts of needle pairs, which can be quite brittle, and orange/reddish bark.
Number nine on our most watched list is ID That Tree: Pin Oak. This video, which debuted in December 2021, was viewed 4,100 times in 2023.
9 – ID That Tree: Pin Oak — On this edition of ID That Tree, meet a species of native Indiana oak from the broad red/black oak family, which is found in bottomlands and areas with imperfectly drained soil, the Pin Oak. This species is recognizable by round acorns with flat scales, bristle-tipped leaves with deep 90-degree angled lobes, and lower branches that angle downward.
Number 10 on our most watched list is ID That Tree: Honey Locust. This video, which debuted in October 2021, was seen 3,510 times in 2023.
10 – ID That Tree: Honey Locust — This native tree comes with its own defense system in very large thorns on the stems and trunk. Meet the honey locust. Purdue Extension forester Lenny Farlee explains that large, long yellow seed pods that resemble bean pods, the option of single or doubly compound leaves on the same tree and smooth gray bark also help identify this species.
To see the full article, please visit FNR News & Stories.
Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel (Invasive White Mulberry, Siberian Elm, Tree of Heaven)
Invasive Species Playlist, Playlist, Purdue Extension – FNR YouTube Channel (Asian Bush Honeysuckle, Burning Bush, Callery Pear, Multiflora rose)
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel (Against Invasives, Garlic Mustard, Autumn Olive)
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel (Common Buckthorn, Japanese Barberry)
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Report Invasive, Purdue Extension
Aquatic Invasive Species, Illinois-Indiana Sea Grant (IISG)
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
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store, Purdue Extension Resource Center
Native Trees of the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Wendy Mayer, FNR Communications Coordinator
Purdue University Department of Forestry and Natural Resources
MyDNR, Indiana’s Outdoor Newsletter: The Indiana Natural Resources Foundation, in partnership with the Division of Forestry, is planning another busy year for the Indiana Tree Project. In 2022, more than 11,000 trees were added to Indiana’s public lands through Indiana Tree Project plantings, and this year is expected to be another successful year.

Through a partnership with the Division of Forestry, we are helping Indiana’s forests grow, one tree at a time, with the Indiana Tree Project. Healthy forests in Indiana promote wildlife habitats, clean air and an abundance of outdoor recreation opportunities. It is estimated that 85 percent of Indiana was once forested. Today, only 19 percent of the state is forested. The Indiana Tree Project is much more than just planting trees. Through this project we are adding new acreage to Indiana’s State Forests and we’re trying to add 1,000 acres of new forested land.
When you support the Indiana Tree Project, we provide you with an official tree certificate to demonstrate your support for the smart management of Hoosier forests. It includes the coordinates for the acre on which your tree is, or will be, planted.
Newsletter can be found online: MyDNR Email Newsletter
For more information please visit Help Grow Indiana’s Forests – MyDNR
Resources:
Forest Improvement Handbook, The Education Store, Purdue Extension’s resource center
Harvesting our forests, the wildlife debate, Purdue Extension – Forestry and Natural Resources (FNR) Got Nature? Blog
Wildlife Responses to Timber Harvesting, The Education Store
Breeding Birds and Forest Management: the Hardwood Ecosystem Experiment and the Central Hardwoods Region, The Education Store
Forest Management for Reptiles and Amphibians: A Technical Guide for the Midwest, The Education Store
Hardwood Ecosystem Experiment – Forest Birds , Purdue Extension – FNR YouTube Channel
Managing Woodlands for Birds , Purdue Extension – FNR YouTube Channel
Sustaining Our Oak-Hickory Forests , Purdue Extension – FNR YouTube Channel
Ask the Expert: Hardwood Ecosystem Experiment – Birds and Salamander Research, Purdue Extension – FNR
Subscribe to Purdue Extension-FNR YouTube Channel
Indiana Department of Natural Resources, Department of Fish & Wildlife