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April 15
Return of the American Chestnut?

In the late 1800s, 25% of hardwood trees in North America’s eastern forest were American chestnuts. 40 meters high and 2 meters across, they provided abundant resources for both people and wildlife in the form of food, shelter, and building materials. Lightweight, rot-resistant, straight-grained and easy to work with, chestnut wood was used to build houses, barns, telegraph poles, railroad ties, furniture and even musical instruments. The rapid decline of the chestnut due to the pathogenic fungus Cryphonectria parasitica has been a subject of much debate and despair over the years: but now, chestnuts engineered to battle the fungus might give the iconic trees a chance to reclaim the North American stage.

By taking genes from wheat, Asian chestnuts, grapes, peppers and other plants and inserting them into American chestnut trees, William Powell of S.U.N.Y.–ESF and scores of collaborators have created hundreds of transgenic trees that are almost 100 percent genetically identical wild American chestnut yet immune to C. parasitica. The scientists hope to get federal approval to begin planting these trees in the forest within the next five years.

National Association of State Foresters blog

Other resources:
Hardwood Tree Improvement and Regeneration Center (HTIRC)
HTIRC Publications including forest restoration of American chestnut.
Indiana Chapter-The American Chestnut Foundation (IN-TACF)

April 14
Protecting Spring Plants from Wildlife Damage Using Repellents

While the weather may tell you otherwise, spring is upon us. With the changing weather comes greening grass, breaking buds, and sprouting plants. This plethora of fresh growth can help cure the winter blues, but it also provides wildlife with a desirable food source. Recently you may have noticed deer and other wildlife increase utilization of winter wheat fields and other green areas like lawns – early spring is the time you see deer in Indiana feed extensively on grass.

For homeowners, this is the time you need to scout around your home for emerging plants in your landscaping beds. Plants that are frequently browsed by deer such as tulips or hostas need special attention, but the limited amount of green plant material can leave any plant as a potential target. Most homeowners choose a type of taste repellent to protect plants.  There are several tips on how to increase the efficacy of this approach.Emerging tulips in a landscaping bed.

  1. Timing: It helps to have some foresight into when damage is likely to occur and/or the plant developmental stage(s). Unfortunately, this is usually based on past experience. Ideally, you want to time applications during these periods.  With tulips, for example, applying repellents early during sprouting, later during sprouting, and during flower bud develop will prevent damage during most years.
  2. Type of repellent: There are many types of taste repellents labeled for deer and other wildlife species. Most have a combination of capsaicin, putrefied egg solids, and/or fatty acids of ammonium soaps. There are of course others with different ingredients.  So which do you choose? There have been many studies that have investigated the efficacy of repellents. The bottom line – they work, but control is not 100%.
  3. Label: Failures can often result in not following the directions on the label. The label also provides safety information and what you can/can’t spray. Read and follow the label – it’s the law.
  4. Expectations: You aren’t going to solve all of your wildlife problems by spraying a few plants or even everything. If you use repellents, reapply according to label directions (every 3-4 weeks is usually a good rule of thumb).  To increase success, you may use them as part of an integrated approach that includes exclusion, cultural practices, and other approaches.

Resources:
Diagnosing and Controlling Wildlife Damage
Preventing Wildlife Damage - Do You Need a Permit?
Corn and Soybean Crop Depredation by Wildlife
Wildlife Conflicts

Brian MacGowan, Extension Wildlife Specialist
Department of Forestry and Natural Resources​

April 10
Dead fish in northern Indiana lakes common

Although thousands of gizzard shad died this winter in northern Indiana lakes, DNR biologists say the loss of the unwanted fish is a good thing.

Shad are not targeted by anglers because of their foul flavor, and they compete for habitat and food with popular sport fish. Where shad are abundant, corrective steps are often needed to control their population.

“Controlling gizzard shad numbers is one of our biggest fish management challenges,” said Jeremy Price, DNR regional fisheries supervisor.

More . . .

Indiana Department of Natural Resources (INDNR), April 7, 2014
Shad die-offs in northern Indiana lakes common

April 04
Question: What do we do about winter burn of Evergreens?

Winter burn is a common occurrence to boxwood, holly, rhododendron, and most conifers. Winter burn symptoms often develop when temperatures warm up in late winter and early spring. This type of winter damage is often misdiagnosed as an infectious disease or damage from excessively cold temperatures.

To understand winter injury, it is important to understand that while a plant is creating its food by photosynthesis, it is releasing large amounts of water through the process of transpiration (the evaporation of water from the plant). Over the course of a day, a large tree can lose hundreds of gallons of water. When plants are unable to obtain the water they need (due to drought or frozen soil), the water lost through transpiration cannot be replenished, resulting in dehydration, foliar damage, and even death.

More . . .

Contacts:
Michael Mickelbart, Clinical Engagement Assistant Professor
Horticulture and Landscape Architecture

Janna Beckerman, Associate Professor
Botany and Plant Pathology

March 31
Question: Tree has large icicle from where it is dripping sap, is this a concern?

Tree owners who have broken limbs in their trees or just taking advantage of early pruning opportunities may notice that large amounts of “water” which seem to be pouring out of the branch. This is actually “sap” seeping out of the damaged area. This is sap that would have been going into the limb or branch that was removed. However, since the limb is no longer there, the sap has nowhere to go but out of the freshly cut limb or wound.

Spring weather signals trees to come out of dormancy and all trees start pumping water, minerals, and carbohydrates upwards into the tree, to allow growth of buds, leaves and shoots and will continue throughout the growing season. Certain tree species, such as maple, birch, dogwood, and elms, have an exceptionally heavy sap flow in the early spring. When pruned or wounded, these trees will "bleed" and is quite noticeable. Under normal circumstances, it is best to delay pruning these trees until later in the growing season, when the flow of sap is slower.

There is no need for alarm if this sap flow occurs and the overall health of the tree is not going to be affected. The "bleeding" may be objectionable from a cosmetic standpoint, especially if the sap is dripping directly onto people, cars, or other targets beneath the wounded area. As the affected area on the tree develops callus material and naturally seals off the wound, it will slow the flow to a stop.

It is not recommended to use any type of wound dressing or covering as this will impede the ability of the tree to seal off the damaged area. Be patient and allow natural healing of the wound to occur. Always use good pruning practices and minimize the size of cut branches to reduce wound size on the tree.

Refer to the following Purdue Extension publication Trees Need a Proper Start: Prune Them Right for more information.

Other resources can be found at the Purdue Extension, The Education Store:
Pruning Ornamental Trees and Shrubs

Lindsey Purcell, Urban Forestry Specialist
Department of Forestry and Natural Resources, Purdue University

March 27
Deer population causing invasive plants to take over our forests?

A recent article in ScienceDaily titled "Excessive deer populations hurt native plant biodiversity" shares how an over population of deer is hurting native plant growth. Landowners seek best management practices as these challenges arise.

For article view University of Miami. "Excessive deer populations hurt native plant biodiversity." ScienceDaily, 20 March 2014.

Resources:
Coping with wildlife damage​, Purdue EVERYTHING Wildlife
How to Build a Plastic Mesh Deer Exclusion Fence, Purdue Extension Publication

Purdue Forestry & Natural Resources Extension

March 19
If you think emerald ash borer was killed by the cold, you are dead wrong

Don't be fooled by the cold weather; EAB has plenty of life left.

Headlines have been circulating suggesting that EAB may "have met its match." Although the Midwest experienced abnormally cold temperatures this winter, it is unlikely EAB populations felt these effects as significantly as your heating bill. EAB, as well as most insects in colder climates, are effective at surviving cold temperatures. One way they survive the cold is by producing an antifreeze-like substance that prevents water in their cells from crystallizing and causing damage. Also, the extra insulation provided by the tree bark helps larvae withstand such cold temperatures. For EAB larvae overwintering within ash trees, death occurs when temperatures reach -28oF.

A model produced by US Forest Service scientists predicts areas in North America where temperatures were cold enough to kill EAB larvae. This model suggests that in the US, only northern parts of Minnesota and North Dakota have reached frigid enough temperatures to affect EAB populations.

Although some parts of the United States may have fewer adults emerging in the spring as a result of the cold temperatures, they probably won't notice. Due to a high reproductive rate, it will likely be only a matter of time before populations rebound to previous levels.

Despite the cold weather, experts are still advising to continue with EAB management plans. One effective means of saving ash trees and reducing management costs is to partner with interested neighbors to hire a company to treat trees in your neighborhood. This collaborative approach will likely reduce transportation and consultation costs for the company and the savings will be passed down to homeowners.

For more information on EAB, treatment options, and NABB (Neighbors Against Bad Bugs) visit Emerald Ash Borer in Indiana, Purdue Extension, web site.

Contacts:
Adam Witte, Exotic Forest Pest Educator
Department of Entomology

Matthew Ginzel, Associate Professor
Departments of Entomology
Forestry & Natural Resources

March 13
Winter damage of the furry kind . . .
Rabbit damage to tree Rabbit damage to tree

Cold winter winds, alternating extreme temperatures, ice and snow, can be damaging to trees and shrubs. However, this spring, we are seeing additional damage due to the harsh winter conditions that is of the furry kind; rabbits and rodents. Mice and rabbits often damage young trees in the winter by feeding on the juicy, green cambium layer just under the bark and girdling the tree. Damage from these furry creatures occurs most commonly in winters when there is prolonged, heavy snow cover and food is scarce; sound familiar? Rabbits feed on the bark above the snow, while mice tunnel under the snow and feed near the ground level. Mouse damage is usually more severe when the trees are surrounded by heavy grass, weed cover or heavy mulch.

On young trees and multi-stemmed ornamental trees, rabbits remove the bark completely around the trunks and stems, effectively girdling them. All growth above the girdled areas will eventually decline and die and for most situations, replacing the girdled trees is the best course of action. There are no applications that will mitigate the effects of rabbit damage or save severely damaged trees. Wound dressings, pruning paints, latex paints, wrappings and other alleged protective barriers do not help.

Many deciduous shrubs have the ability to produce new shoots or suckers at their base. Because of this ability, many severely damaged deciduous shrubs can recover. However, patience is required as several years may be required for some shrubs to fully recover. In early spring as the greening begins, prune off girdled stems just below the damaged areas. This will help rejuvenate the plant, in most circumstances, and replace the damage growth.

The most effective deterrent to girdling by mice or rabbits is to wrap the trunk and low branches of young trees with screen wire or hardware cloth. Be certain the wire wrap is buried below the ground line and extends high enough above the possible snow line to prevent rabbits from reaching to trunk or branches. To help control mouse damage, maintain an area free of grass or weeds for a 1- to 2-foot radius around the base of the tree. Additionally, maintain proper mulch levels, never more than 2-3”, to eliminate the habitat for mice. Various chemicals are available to repel mice and rabbits, but these do not afford the reliability of a well-made barrier.

Mice damage to treeMice damage to tree

Lindsey Purcell, Urban Forestry Specialist
Department of Forestry and Natural Resources, Purdue University

Other resources:
Preventing Wildlife Damage, The Education Store/Purdue Extension
Wildlife, Pet and Wildlife Damage, Purdue FNR Extension

February 25
Question: Isn’t there concerns about consuming Asian carp as a food source in Indiana streams?

A recent discussion about Asian carp as a food source has generated some concerns about the level of contamination in their fillets, and thus, whether or not they are safe to eat. Several Indiana agencies cooperate to evaluate the risks of fish consumption to the public; the agencies include Indiana Department of Natural Resources (IDNR), Indiana Department of Environmental Management (IDEM), Indiana State Department of Health (ISDH), and Purdue University. Most of the fish assessed for contaminants are those that are regularly caught by anglers. Numerous catfish, bass, sunfish, and sucker species are commonly included in tissue surveys (see links below for more info). Indiana then divides people into two risk groups; 1) men (over 15yrs) and women beyond childbearing age (typically 45yrs or older), and 2) women pregnant or capable of becoming pregnant and children under 15. The second group is considered the sensitive group and allowable contaminant levels (that is, the amount of fish it is safe to consume) are set significantly lower.

It is important to recognize that there are differences in allowable contaminants among population groups mentioned above, and it is equally important to recognize that the same fish species can have different amounts of contaminants in different water bodies. Asian carp are a riverine species that frequently travel long distances, and as such they are exposed to varying levels of contaminates. Indiana and many other states try to minimize the effects of variation in individual fish fillet by combining tissue from multiple individual fish and analyzing it as a composite. Sampling the tissue as a composite reduces the risk of a heavily contaminated fish, or a fish with little contamination, giving a false impression of the risk. By combining the fillets, Indiana also saves money by not analyzing large amounts of single fillets. Indiana does divide the fish into a couple of size classes for each composite, because contamination increases significantly as fish sized increases. They have yet to begin testing Asian carp fillets, at least partially because of their difficulty to capture using traditional fish survey techniques.

Although most states have not started regularly testing Asian carp, there has been some published research evaluating Asian carp fillets and comparing their contaminants to other species caught in the same location. Not surprisingly, the results of the research found that Asian carp have different concentrations of contaminants depending on where they are found, and they have different levels than other species of fish including common carp. Common carp have a completely different diet than Asian carp so it is not surprising that contamination levels are different. Like most other fish the most common problems associated with Asian carp are Mercury and PCB’s. However, where the research was conducted in Illinois and Missouri the recommended restriction on consumption was typically 1 meal per week for the most sensitive groups. Most studies have demonstrated that larger fish tend to have higher concentrations in their tissues than smaller fish found in the same environments. This relates to the way Mercury and PCB’s bioaccumulate in tissues – the longer a fish is around the more contaminates per gram we would expect them to contain. This is not to say that Asian carp in Indiana is safe for that level of consumption, or that it even contains the same amount of contaminants as in other states. It still needs to be evaluated by the state, but studies cited below have shown that for the most part Asian carp are likely no riskier to consume than most of the fish species Indiana currently evaluates.

Resources:
Fish Consumption Advisory
Indiana State Department of Health

Angling Indiana/Consumption Advisory by County
Purdue University

Asian carp solutions: Take them to market
Illinois-Indiana Sea Grant (IISG) Newsroom

No bones about it: New video lays out easy steps for filleting tasty Asian Carp
Illinois-Indiana Sea Grant (IISG) Newsroom

Published Papers:
Levengood, J.M., D.J. Soucek, G.G. Sass, A. Dickinson, and J.M. Epifanio. In press. Elements of concern in fillets of bighead and silver carp from the Illinois River, Illinois. Chemosphere 2013.

Orazio, C.E., D.C. Chapman, T.W. May, J.C. Meadows, M.J. Walther, J.E. Deters, K.R. Echols, and E.S. Dierenfeld. 2010. Evaluation of environmental Contaminants and elements in Bigheaded carps of the Missouri River at Easley, Missouri, USA. In: Chapman, D.C. and M.H. Hoff, (Eds.). Invasive Asian carps in North America. American Fisheries Society Symposium 74, Bethesda, Maryland, 2011, pp 199-213.

Rogowski, D.L., D.J. Soucek, J.M. Levengood, S.R. Johnson, J.H. Chick, J.M. Dettmers, M.A. Pegg, and J.M. Epifanio. 2009. Contaminant concentrations in Asian carps, invasive species in the Mississippi and Illinois Rivers. Environmental Monitoring and Assessment

Jay Beugly, Aquatics Ecology Specialist
Department of Forestry and Natural Resources (FNR)
Illinois-Indiana Sea Grant (IISG)
Purdue University

February 21
National Wildlife Federation Launches Online Community to Connect Kids with Wildlife - National Wildlife Federation, @NWF

Watching a pair of blue jays frolic in a bird-bath. Sitting on a park bench observing squirrels chase each other around a giant oak tree. Gardening in your backyard. Planting a tree. Fishing along a misty river. Seeing turtles sunbathe on a log in a local lake. Counting stars by a dying camp fire in a state park. People who love the outdoors and wildlife are invited to check out a new online community called Wildlife Nation that the National Wildlife Federation is launching today with the goal of connecting people with each other in order to instill a love of wildlife in children. You can visit Wildlife Nation at: www.wildlifenation.org.

More . . .​

National Wildlife Federation
Jordan Lubetkin 

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For publications:
The Education Store

Purdue Nature of Teaching
HelptheHellbender.org
Indiana Department of Natural Resources
Master Gardener, Purdue University
Tree Doctor App, Purdue University
Purdue Plant & Pest Diagnostic Laboratory
Purdue Six Legs News Column
Purdue Yard and Garden