Purdue Landscape Report: Just as sure as you try to predict the weather, it is likely to change. But going out on a limb, I predict that we will have a bit of a dud for fall color display this year. Not a very risky prediction, considering that many plants already are starting to turn color and/or drop leaves in some areas of the state.
So why would the colors be early and/or a bit duller than usual? Certainly, some of the reason why plants display fall colors has to do with the genetic makeup of the plant. That doesn’t change from year to year. But the timing and intensity of fall colors do vary, depending on factors such as availability of soil moisture and plant nutrients, as well as environmental signals such as temperature, sunlight, length of day, and cool nighttime temperatures.
The droughty conditions experienced during much of the second half of summer are likely to have decreased the amount of fall color pigment. Southern Indiana has been particularly parched. Despite recent rains in some areas, much of the state remains designated as abnormally dry to moderate drought. You can check your area’s conditions at the US Drought Monitor for Indiana. Additional maps and data is available at the Midwest Regional Climate Center.
Growing conditions throughout the season affect fall color as does current weather. Colors such as orange and yellow, which we see in the fall, are actually present in the leaf all summer. However, those colors are masked by the presence of chlorophyll, the substance responsible for green color in plants during the summer. Chlorophyll allows the plant to use sunlight and carbon dioxide from the air to produce carbohydrates (sugars and starch). Trees continually replenish their supply of chlorophyll during the growing season.
As the days grow shorter and (usually) temperatures cooler, the trees use chlorophyll faster than they can replace it. The green color fades as the level of chlorophyll decreases, allowing the other colored pigments to show through. Plants that are under stress–from conditions like prolonged dry spells–often will display early fall color because they are unable to produce as much chlorophyll.
Yellow, brown and orange colors, common to such trees as birch, some maples, hickory and aspen, come from pigments called carotenoids, the same pigments that are responsible for the color of carrots, corn and bananas.
Red and purple colors common to sweet gum, dogwoods and some maples and oaks are produced by another type of pigment called anthocyanin, the pigment responsible for the color of cherries, grapes, apples and blueberries. Unlike chlorophyll and carotenoids, anthocyanins are not always present in the leaf but are produced in late summer when environmental signals occur. Anthocyanins also combine with carotenoids to produce the fiery red, orange, and bronze colors found in sumac, oaks, and dogwoods.
Red colors tend to be most intense when days are warm and sunny, but nights are cool–below 45º F. The color intensifies because more sugars are produced during warm, sunny days; cool night temperatures cause the sugars to remain in the leaves. Pigments are formed from these sugars, so the more sugar in the leaf, the more pigment, and, thus, more intense colors. Warm, rainy fall weather decreases the amount of sugar and pigment production. Warm nights cause what sugars that are made to move out of the leaves, so that leaf colors are muted.
Leaf color also can vary from tree to tree and even from one side of a tree to another. Leaves that are more exposed to the sun tend to show more red coloration while those in the shade turn yellow. Stress such as drought, poor fertility, disease or insects may cause fall color to come on earlier, but usually results in less intense coloration, too. And stress or an abrupt hard freeze can cause leaves to drop before they have a chance to change color.
So far, weather conditions lead me to think this will be one of those not so showy fall color years. I hope I am proven wrong!
Why do leaves change color and why do leaves fall off in autumn?, Got Nature? Blog
Why Leaves Change Color, The Education Store, Purdue Extension
Fifty Trees of the Midwest App for the iPhone, The Education Store
Native Trees of the Midwest, The Education Store
Why Leaves Change Color, USDA Forest Service, Northeastern Area
It’s Fall, but why are the leaves still green? article and video, WLFI.com
B. Rosie Lerner, Extension Consumer Horticulturist
Purdue Horticulture and Landscape Architecture
Be on the watch for deer with EHD in Indiana
Recently, a white-tailed deer in Clarke County Indiana tested positive for Epizootic Hemorrhagic Disease (EHD), and potential EHD cases have 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.
What is EHD and BTV?
Epizootic hemorrhagic disease (EHD) and bluetongue virus (BTV) are viral diseases, collectively called hemorrhagic diseases (HD), and are common in white-tailed deer. Both diseases are transmitted by biting midges often called “no-see-ums” or gnats. Neither disease is a human health issue, but they can cause significant mortality in white-tailed deer. Outbreaks of HD tend to impact deer populations locally, meaning an outbreak may occur in one part of a county but not in other parts.
When do EHD outbreaks occur?
EHD and BTV outbreaks often occur in late summer and early fall (August-September), especially in years with drought-like conditions. Drought causes water sources to shrink, which creates warm, shallow, and stagnant pockets of water creating ideal breeding habitat for the midges that transmit EHD. Deer also congregate in these areas to find water, which helps the midges pass the disease between infected and healthy deer. EHD outbreaks can last until a frost that kills the midges.
What are the signs of a deer with EHD?
Deer with EHD often appear weak, lethargic, and disoriented. Other signs of EHD in deer are ulcers in the mouth or on the tongue, swollen face, neck, or eyelids, and a bluish color to the tongue. Deer with EHD often search for water to combat the fever caused by the disease. EHD can be confirmed by testing blood and tissue (i.e., spleen) samples, but samples must be collected shortly after death.
Where am I likely to find a deer with EHD?
Because deer with EHD often seek out water to combat the resulting fever, deer killed by EHD are commonly found around water. If you have a stream, creek, river, or other source of water on your property, looking in the vicinity of those areas can help you locate deer that have succumb to EHD.
What do I do if I find a deer I think has EHD?
If you come across a sick or dead deer that you think has EHD you can report it through an online reporting system run by the Indiana DNR. Here is a link to the reporting system: Report a Dead or Sick Deer.
Can deer survive an EHD outbreak?
Yes, some deer will survive EHD. While up to 90% of deer that contract EHD may die from the disease, the deer that survive build up antibodies to EHD, which may make them immune to future outbreaks. Additionally, does may pass the antibodies and immunity to their offspring.
How can I tell if a deer I killed during hunting season has survived EHD?
If you kill a deer during the hunting season this year, pay attention to the hooves. Deer that survive an EHD outbreak often have indentions or cracks on their hooves (see picture).
Sloughing or splitting hooves on two or more feet of a deer taken during the fall hunting season are typlical of chronic HD. Photo used courtesy of the Southeastern Cooperative Wildlife Disease Study.
Are deer that have survived EHD safe to eat?
Yes, deer that have survived EHD are safe to eat.
For updated information on EHD in Indiana check out the Indiana DNR – Epizootic Hemorrhagic Disease web page.
Report a Sick or Dead Deer, Indiana Department of Natural Resources (IN-DNR)
EHD Virus in Deer: How to Detect and Report video, Quality Deer Management Association
Epizootic Hemorrhagic Disease (pdf), Cornell University
How to Score Your White-Tailed Deer video, Purdue Extension – FNR YouTube Playlist
Deer Harvest Data Collection, Purdue FNR Got Nature? blog
Jarred Brooke, Wildlife Extension Specialist
Purdue Forestry and Natural Resources
The Indiana Woodland Steward Homepage has just been updated with a new newsletter and is available to view on the website. The Indiana Woodland Steward Newsletter is a resource that’s full of a variety of valuable information to foresters, woodland owners, timber marketing specialists and any woodland enthusiasts. This issue includes topics such as hardwood strategy, terrestrial invasive species rule, tick-borne diseases, spring time woodland evaluations, as well as much more.
The Indiana Woodland Steward Institute is an entity made from 11 organizations within the state including Purdue University, Indiana DNR, and Indiana Hardwood Lumbermen’s Association that works to promote best usage practices of Indiana’s woodland resources through their Woodland Steward publication.
Brian MacGowan, Extension Wildlife Specialist
Department of Forestry & Natural Resources, Purdue University
Purdue University’s Tick INsiders program is looking for Indiana high school students and other Indiana residents willing to roll down their sleeves to get involved in a citizen science project.
Cate Hill, a Purdue professor of entomology, leads this effort to analyze the bacteria and viruses in Indiana’s ticks to build an understanding of what they are carrying and how that might impact human health. To do that, she needs volunteers to collect ticks from all over the state.
This year the Tick INsiders program will provide training for up to 50 students. Citizen scientists are also now welcome to collect and send ticks to Hill’s lab.
“It’s really important work. The Centers for Disease Control and Prevention reports that human cases of tick-borne diseases doubled from 2004 to 2016. If we’re going to get a handle on that and develop strategies for reducing tick bites and treating patients, we need to know where our ticks are and what our ticks are carrying around inside them,” Hill said. “That means we need a lot of ticks, and we need help collecting them.”
Three species of ticks – the blacklegged or deer tick, the lone star tick and the American dog tick – are found in Indiana. These ticks can transmit multiple pathogens, nine of which are known to cause human illnesses, though not all have been identified in Indiana. The Indiana State Department of Health reports more than 100 cases of Lyme disease each year and dozens of cases of Ehrlichiosis, anaplasmosis and Rocky Mountain spotted fever.
Research suggests that ticks can carry a cocktail of microbes – bacteria and viruses – that can sicken bite victims and may work in concert to affect the severity of an illness and human immune response.
“Not all tick bites are the same. We don’t know what is passed from a tick to a human each time someone is bitten, which means that health care professionals may need to consider multiple tick-borne pathogens in a person who has been bitten by a tick,” Hill said. “This program improves our knowledge so that we can improve our outcomes.”
Indiana residents interested in participating can collect ticks and send them to Hill’s lab for analysis. Videos on safe and proper collection techniques, as well as how to send ticks will be at Tick INsiders.
For full article, see Purdue Agriculture News.
Ticks 101: A Quick Start Guide to Indiana Tick Vectors, The Education Store – Extension Resource
The Biology and Medical Importance of Ticks in Indiana, The Education Store
Mosquitoes, Purdue Extension Entomology
One Small Bite: One Large Problem, Got Nature?, Purdue Extension-Forestry and Natural Resources
Mosquitoes and ticks – little pests carry big risks, Got Nature?
Catherine A Hill, Professor of Entomology/Vector Biology
Purdue University Department of Entomology
Forest management in the eastern United States is faced with many modern challenges. Professional foresters have an innovative set of management options for the maintenance of healthy forest ecosystems. But some options raise public objections when applied to public lands (e.g., types of timber harvest, prescribed fire) and the effects of some management options on forests and their native inhabitants are poorly understood. Moreover, forest lands in the eastern and Midwestern United States primarily are in small privately-owned parcels that change ownership relatively frequently. These lands are often managed for short-term financial gains rather than long-term sustainability.
As populations of some forest organisms decline, restrictions on landowners may increase because species become classified as endangered or threatened (e.g., the Indiana bat), while increasing populations of other species (white-tailed deer, invasive plants) create economic and ecological challenges. These problems are compounded by the lack of scientifically rigorous research on the overall impacts of forest management on the effected ecosystems and their components. To address this set of issues, the Hardwood Ecosystem Experiment (HEE), a long-term, large-scale experimental study of forest management and its impacts, was initiated in 2006.
Many of Indiana’s forests have been dominated by oak and hickory trees for thousands of years. The historical conditions that shaped today’s forests have changed, altering forest composition and leading land managers to wonder what can be done to maintain oak and hickory forests for the future. The Hardwood Ecosystem Experiment: 2006-2016 provides an overview of findings for the first 10 years of the HEE, 100 year project.
To learn more about this 100 year forest management plan and see its impacts, check out the Hardwood Ecosystem Experiment website.
If you would like to start receiving “The HEE Update,” please email Charlotte Owings, the HEE project coordinator, at firstname.lastname@example.org. If you do not have an email address, you may still receive the newsletter by regular postal mail – call Charlotte Owings at 765-494-1472.
The Hardwood Ecosystem Experiment website
The Hardwood Ecosystem Experiment: 2006-2016, The Education Store, Purdue Extension resource center
The Hardwood Ecosystem Experiment: Indiana Forestry and Wildlife, The Education Store
Hardwood Ecosystem Experiment – Wildlife Responses to Timber Harvesting, The Education Store
Hardwood Ecosystem Experiment – Sustaining Our Oak-Hickory Forests, The Education Store
Hardwood Ecosystem Experiment – Forest Birds, Purdue Extension-FNR YouTube Playlist
Invasive Plants: Impact on Environment and People, The Education Store
The Great Clearcut Controversy, The Education Store
Charlotte Owings, Hardwood Ecosystem Experiment (HEE) Project Coordinator
Purdue Forestry and Natural Resources
Not sure when hunting season starts for you? This year’s Indiana Department of Natural Resources Hunting and Trapping Open Season Schedule is now available. Below are a few of the dates in each game category when season opens. See PDF for full list of dates and details Hunting Season (pdf)
For license information, youth hunting information, private land permission form and more check out IDNR Hunting and Trapping.
Hunting Season Open
Red and Gray Fox, October 15
Woodland Big Game
Deer Youth, September 28
Woodland Small Game
Gray and Fox Squirrel, August 15
Pheasant, November 1
Crow, July 1
Handling Harvested Game: Field Dressing (Deer), The Education Store
Wild Bulletin E-newsletter, Division of Fish & Wildlife
Indiana Department of Natural Resources
This latest cold snap could kill some emerald ash borer populations in northern states like Minnesota. But in warmer states like Indiana, the invasive borer is one resilient bug.
“These guys are pretty good at burrowing in underneath the bark of the tree and that tree helps to insulate them from the bulk of the bad weather,” says Megan Abraham, director of the Indiana Department of Natural Resources Division of Entomology and Plant Pathology.
As a result, Abraham says it takes a long cold spell with really cold temperatures to kill off an emerald ash borer beetle. According to Purdue University, it would have to get down to about minus 28 degrees.
Kerry Bridges is an arborist with Tree Guy Incorporated in Bloomington. He says the emerald ash borer is not only used to Indiana winters, but it’s survived in much colder areas like Canada.
“I don’t foresee significant change or restriction of that bug’s reproduction and spread,” Bridges says.
What’s more, emerald ash borer and some other insects have a unique way of keeping warm.
Purdue entomologist Cliff Sadof says the reason your nose starts to run when it’s cold out is because your body is trying to keep it from freezing. Mixing mucus with water lowers the freezing point. Sadof says insects like the emerald ash borer do something similar.
“But they are changing the composition of the fluids inside their body, so they act like antifreezes,” he says.
According to the Indiana Department of Natural Resources, the emerald ash borer has devastated ash trees in every county in the state. Bridges encourages homeowners that are having problems with emerald ash borer to keep treating their trees…
For full article view:
How The Emerald Ash Borer Will Survive Indiana’s Cold Snap, Indiana Public Media News from WFIU Public Radio and WTIU Public Television, Indiana University, written by Rebecca.
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 Cost Calculator – Purdue Extension Entomology
WFIU Public Radio and WTIU Public Television
Groundhogs are good at many things, said Brian MacGowan, Purdue University Extension wildlife specialist and Forestry and Natural Resources Extension coordinator, but predicting the weather definitely isn’t one of them.
The lore surrounding Groundhog Day originated in Germany where people used the reactions of badgers and hedgehogs to gauge weather patterns. When the tradition eventually migrated to America, Jarred Brooke, Extension wildlife specialist, said hedgehogs, which can be found throughout the United States, became the mammalian forecaster of choice.
“They’re crafty little critters,” McGowan explains, “which is why they’re found in so many different places. They’re habitat generalists and can live in open woodlands, grasslands, what have you.”
While MacGowan and Brooke agreed groundhogs don’t have a great track-record of weather prediction, other facts make groundhogs one of the more interesting members of the squirrel-family.
For full article see: Groundhogs can’t predict the weather but they do poop underground.
Selecting a Nuisance Wildlife Control Professional – The Education Store, Purdue Extension Resource Center
Preventing Wildlife Damage – Do You Need a Permit? – The Education Store
The Basics of Managing Wildlife on Agricultural Lands – The Education Store
Nuisance Wildlife – Indiana Department of Natural Resources
Dealing with nuisance geese this spring – Got Nature?
Animal Damage Management: Woodchucks, The Education Store
Brian MacGowan, Wildlife Extension Specialist
Purdue University, Forestry and Natural Resources
With winter upon us this is actually a good time to look for owls on your property. Most owls breed from January to March. You can either listen for calls in the evening, or use owl calls or recorded calls to get responses from owls in the area. We have three common species in Indiana and one rare species. All are non-migratory. However, each has different needs and habits. The following descriptions were written by Barny Dunning, professor of wildlife ecology at Purdue, and Jeff Riegel, field project supervisor at Purdue. These accounts were originally published in the Indiana Woodland Steward (www.inwoodlands.org).
Owls are among the most intriguing animals native to Indiana. They have been celebrated in story from the myths of the early Greeks to the books of Harry Potter. Owls are common across much of the state, but are relatively unknown, probably because of the nocturnal habits of these birds. But since they are efficient predators of mice and rats, among other things, owls are very useful birds to have around. Three species of owls are common year-round residents in Hoosier forests. The largest of these is the great horned owl, one of the dominant predators of our forests. Most people are surprised to learn that the great horned owl is as common as the familiar redtailed hawk even though the owl is much less likely to be seen.
Great horned owls hunt in open areas but nest in large trees, where they take over a nest abandoned by a hawk, crow or heron. They are common where both woods and fields mix. The owls start breeding in January and February, adding new sticks to an old nest and laying a clutch of three eggs. Most species of owls nest very early in the year so that there will be a lot of easily caught prey in the form of young mammals and birds when the owl chicks are learning to hunt on their own. Many nests of the great horned owl are in snags or trees with broken tops, therefore retaining some of these forest features will provide good nesting spots for this dominant bird.
A second species of large owl is found in the larger woodlands of Indiana. The barred owl is most common in the interiors of forests and spends less time along the woodland edge. One major reason for this is the presence of the great horned owls, which will kill and eat a barred owl. Barred owls usually nest in the cavities of deciduous trees, laying their eggs in deep winter. Their dependence on tree cavities means that barred owls are likely to respond well to land management activities that retain large trees on a property and increase the number of snags with cavities. They also do well when there are forest patches of a variety of ages on a property, in addition to the older trees that provide nest sites.
Eastern screech-owls are the smallest resident owl in the state. They nest in small tree cavities and readily make use of nest boxes made especially for them. More than the other two species, screech-owls are found in suburban backyards, urban parks and on college campuses – anywhere there is a variety of trees and shrubs. Screech-owls feed on small prey such as insects, songbirds and mice. They breed later than do the big owls, and have active nests in March and April. In addition to nest boxes, these owls willuse old cavities excavated by northern flickers, tree holes created by storm damage, and hollow trunksof snags. Their ready use of a wide variety of cavity types makes our screech-owls a prime beneficiaryof snag retention and other habitat improvement activities. Indiana’s smallest owl does not breed here, but its numbers during the fall migration can be in the thousands statewide. The northern saw-whet owlbreeds from the most northern states on into Canada and migrates from there when food becomes scarce. “Swets” are an irruptive species, meaning their populations rise and fall dramatically from one year to the next on a roughly four-year cycle. A group of volunteer researchers in Yellowwood State Forest began studying the movements of these owls in 2002 as part of the larger Project Owlnet (www.projectowlnet.org). Their first year produced 71 owls on just one ridge in Yellowwood. Since then, the annual numbers have averaged around 70, but nearly 200 owls were captured and banded on that same ridge in 2007. The low point in the cycle was in 2009 when only nine owls were captured. There are now eight such banding stations scattered around Indiana. Brookeville Reservoir had the largest number of captures in 2009 with 32; while an Indianapolis station tallied only six. Some northern saw-whet owls winter in Indiana where forests with an open understory provide good foraging opportunities throughout the winter months.
The rarest owl in Indiana is, paradoxically, the species with the largest geographic range. Barn owls are found across the globe, but in the Midwestern United States their populations have declined dramatically. The species is considered endangered in Indiana. Barn owls originally nested in tree cavities, but when early settlers built barns and other farm buildings, the owls were quick to adapt. They are not limited to barns however, as recent Hoosier nests have been found in old churches, silos, and within the walls of abandoned buildings. To be suitable, human structures must have openings that allow the owls to fly in and out and an interior area that is undisturbed and big enough for the nest. The biggest factor in their decline has been changing agricultural practices. Barn owls hunt in open areas such as pastures, but do not use rowcrop fields. As Hoosier farmers converted pastures to corn and soybean, the barn owl lost its hunting grounds. Farmers in the southern part of the state that still retain some open grassy fields on their land can contact the state Department of Natural Resources to have a barn owl nest box added to their outbuildings if they don’t have appropriate nest sites.
Learn how forests are used by birds new videos, Got Nature? Blog
Managing Woodlands for Birds, The Education Store-Purdue Extension resource center
Climate Change + Birds, Purdue Climate Change Research Center
Brian MacGowan, Wildlife Extension Specialist
Purdue University, Forestry and Natural Resources
It all starts with providing some supplemental nutrition for small to medium-aged trees in the late fall when trees go into a state of dormancy. This is when trees stop active growth and begin to form terminal buds, drop leaves and develop cold resistance. Adding fertilizer to trees too early in the season can push new growth which will be prone to winter damage.
A fertilization program is used to maintain trees in a vigorous condition and to improve their immune system against pests. Fertilizing trees refers to the practice of adding supplemental nutrients (chemical elements) required for normal growth and development. However, you really can’t “feed” a tree, since trees are autotrophs. They use nutrients to feed themselves by making sugar in the leaves through photosynthesis.
Nitrogen (N), phosphorus (P), and potassium (K) are plant nutrients needed in the largest quantity and these are most commonly applied as a complete fertilizer. However, the addition of any soil nutrient is recommended only if soil or plant foliage tests indicate a deficiency. For trees and shrubs in most of Indiana, the two most common causes of nutrient problems are high pH (alkaline) soils, which can lead to chronic deficiencies of nutrients in some tree species, such as red maple and pin oak, and nitrogen-deficient soils. Typical symptoms include yellowing chlorotic leaves and reduced growth and smaller leaf size.
Trees in natural settings get nutrients from the air, organic matter, nutrient cycling, and microbial activity. In many cases, supplemental nutrition is not necessary in fertile soils which have enough nutrients in the proper amounts to support healthy growth, especially on established trees, but in the urban and suburban environment, often a little assistance is needed. The more challenging urban environment provides less opportunity for healthy growth due to poor, fragmented soils, reduced microbial activity and compaction. Trees needing fertilization to stimulate growth include those exhibiting the symptoms of pale green, undersized leaves, chlorosis, reduced growth rates and those in decline resulting from insect attacks or disease problems. Also, turf can be a serious contender for nutrients and trees surround by turf benefit from additional nitrogen applications every couple of years.
Trees which should not be fertilized include newly planted trees in the current year and those with root damage from recent trenching, construction or other disturbance. The root systems of these plants will need to re-establish before fertilizers are applied with cultural practices such as supplemental moisture and mulch. Older, established trees do not need to be fertilized every year and may never need supplemental feeding. In fact, serious pest problems can result on over-fertilized trees. Research indicates that young deciduous trees benefit from additional nitrogen in low-analysis, slow release forms. Conifers require less fertilization and are genetically adapted to low-nutrient soils.
For more information on how and when to fertilize trees, refer to HO-140-W, Fertilizing Woody Plants from the Purdue Extension Education Store.
Article shared by: The Landscape Report, Start Preparing Trees for Winter and Next Year.
Lindsey Purcell, Urban Forestry Specialist
Purdue Forestry and Natural Resources