Posts Tagged ‘oak trees’

Oak Wilt Striking Michigan Trees

There is a fungal disease that has made its way into Michigan and is taking out our oak trees. As if we needed another forest pest to worry about, oak wilt has made an appearance in several Michigan counties. This is causing mass clear-cuttings in portions of the state, including in state parks.

The reason? The only way to stop the spread is to cut down all infected trees, and in many cases any oak surrounding an infected tree.

Since it’s relatively new in Michigan, we have an opportunity to help stop the spread. Here are some tips we all can do to help:

  • Watch your trees closely. If something doesn’t look right, report it to the Michigan Department of Natural Resources. It may turn out to be nothing, but it’s better to be safe than sorry.
  • Don’t trim oak trees from April 15 until July 15, or even through the entire summer if you want to err on the safe side. Any injury can create a way for the fungus to get into the tree. This means intentional injuries like trimming, or accidental ones from lawnmowers, weed whips, and storm damage. If you accidentally nick the trunk of your oak trees doing yard work, seal it up with pruning sealer or tree paint.
  • And the last tip we’re going to give is please don’t move firewood. It is tempting to save money and inconvenience by bringing wood with you when you go camping, but this can cause problems by carrying forests pests long distances and bringing them to new areas. Oak wilt is no exception. The fungus spores can live in the bark of firewood and infect healthy trees at your destination. Please buy where you intend to burn!

A Warning for Great Lakes States: A disease called “Oak wilt” is striking Michigan Forests

Oak tree effected by Oak wilt.

By , Great Lakes Now

If you head to Northern Michigan this summer, you might see some disturbing landscapes across the shoreline and in other spots across the state: clear-cutting. In most cases, it’s not because a shopping development or a subdivision is about to be constructed. It’s because of a fast-moving and deadly fungus that takes aim at Oak trees and can kill them in less than four weeks. And the only solution to stop the spread of the disease is to kill the trees it infects.

It’s called “Oak wilt” disease. Great Lakes Now talked with Jenna Johnson who’s a forest technician with AmeriCorps at the Michigan Department of Natural Resources in Cadillac. She says Oak wilt was first discovered in Great Lakes states in the 1940’s. It has caused major damage in Midwestern States like Minnesota but has only recently made its way into Michigan. She says Roscommon, the Gaylord area, Missaukee County, and Kalkaska County are being particularly hard-hit right now.

Beetles spreading Oak wilt


Johnson says, “Oak wilt is a vascular disease. It makes the tree unable to absorb water. It starves the tree to death.” She says the tree starts to die the minute it’s infected, and starts dropping all its leaves. She says it strikes Red oaks, Pin oaks and some White oaks. It’s spread by sap-feeding beetles that take aim at freshly wounded trees. And once one Oak tree is infected, all other Oak trees in the area are in danger of being infected.

She says if the tree isn’t cut down and removed from the area – right into the roots- followed by what’s called “vibratory plowing” down at least 5 feet into the ground to destroy the fungus –   Oak wilt could sweep across the state. The DNR says if Oak wilt isn’t stopped by cutting down infected trees, it could continue to spread, possibly killing almost all the Red oaks in Michigan.

At least 21 states are dealing with the disease, but the majority of Oak wilt cases are being discovered in the Midwest.

The DNR says Oak wilt isn’t just spread through live trees. It’s also spread by firewood that still has its bark. That’s why the DNR wants to get the word out this summer that no one should cut any kind of Oak trees – including power companies – from April 15th to July 15th, and there’s a ban on cutting Oak trees for firewood during this time, too. Bill O’Neill, State Forester of Michigan and Chief of the Forestry Division of the DNR   tells Great Lakes Now if you are gathering or buying firewood, “use and buy your firewood locally – get it from the vicinity where you’re going to be using it.” 

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Of Oaks and Acorns

The Wildlife Benefits of Acorns and Oaks

The time of year has come during which, when I’m reading in the evening in the silence of my home, I hear a sharp thwack! on the roof, followed by an increasingly quieter bump bump bump bump.

blue jay, acorn, oak, mast

Ah yes, the annual attack of the oak trees has commenced, signaled by the sound of acorns storming the roof. And so it goes, for hours, for days. Future generations of oak trees are looking for a little spot of soil to call their own, but ending up—many of them, anyway—in the rain gutters of my house.

We all know that from tiny acorns mighty oak trees grow, but we should add that from tiny acorns also grow deer, gray squirrels, red squirrels, chipmunks, wild turkeys, crows, flying squirrels, rabbits, opossums, blue jays, quail,  raccoons, wood ducks—more than 100 U.S. vertebrate species eat acorns. In autumn and winter, the acorn is the cheeseburger of the forest ecosystem—fairly easy to find and nicely packaged. They are one of the most valuable food resources available for wildlife.

Acorns as Food

Like wine, acorns come in two basic types: red and white, depending on the type of oak they come from. About 90 of the world’s 400 oak species are native to the United States. White oaks, which grow leaves with rounded lobes and drop acorns every year, include species such as the chinkapin, swamp chestnut oak, live oak and post oak. The red oaks (sometimes called black oaks), which bear leaves with pointed lobes and drop acorns every other year, include scrub, willow, southern red, blackjack and black oak.

oak, acorn, mast

Also like their red and white counterparts in wine, a fine red acorn with hints of fiber and overtures of carbohydrate will include more tannin than will a white acorn. This difference in tannin, an astringent chemical common in plants, affects how wildlife use acorns. Although acorns from the red group of oaks tend to be higher in fat, protein, calories and fiber than do acorns from white oaks, the astringent quality (think of how you pucker up when you bite into unripe fruit) of red acorns makes them less palatable to wildlife, both due to taste and digestibility. Ergo, animals vacuum up acorns from the white oak group with more gusto than they do the reds.

However, acorns from white oaks germinate shortly after nestling into the earth, while reds lie dormant for months, meaning that reds will be available as a food longer. Wildlife will turn to nuts from the red-oak group in winter and into spring, when the white varieties are gone.

Acorns can compose more than 75 percent of a white-tailed deer’s diet in late fall and early winter. Deer and other animals, including black bears, alter their distribution patterns in response to acorn production. When an acorn crop is especially good, deer may produce more twin fawns, thanks to improved nutrition. A failed acorn season can cause wildlife populations dependent on acorns to decline.

Acorn Generations

A single oak tree can produce thousands of acorns in one season. My patio in autumn can become covered with acorns, like a carpet of crunchy ball bearings, and a walk in the backyard can turn into a gauntlet of pelting acorns, stinging to head and shoulders. The blasted acorns are everywhere.

Which raises a point you may find interesting. Wild things have two strategies for ensuring that they produce enough offspring to keep the species going—individuals of some species mature fast, produce a lot of young, and die soon (think mice or rabbits); in other species, individuals mature slowly, reproduce slowly, but live long (think of African elephants, with their two-year gestation period usually resulting in a single calf, with females beginning to breed in their mid teens and preferring to mate with males older than 40, and adults sometimes living into their 70s). Long life tends to equal low birth rates, because the individuals have time over the years to produce at least two offspring that mature and reproduce. An oak tree may live for centuries, but they produce hundreds of thousands of acorns, suggesting that despite their size and durability, oaks don’t have a high reproductive success rate. The reason, of course, is all those animals feeding on the nuts. The mighty oak tree is a sitting duck.


oak, acorn, squirrel, mast

Oaks are not alone in producing nuts attractive to wildlife (and people; American Indians ate acorns). Pecans, walnuts and other nuts, along with acorns, belong to the food group ecologists call “mast.” Studies of mast abundance help predict how well species such as deer and squirrels will do in a given year.

Of course acorns are not  the only things oaks contribute to wildlife survival. The trees also offer shade and shelter, leaves and twigs for building nests and even for eating, and participate in the globe’s exchange of oxygen and carbon dioxide as well as in how water moves through an ecosystem.

If you want to provide oaks for wildlife, depending on where you live (get advice from local nurseries) you might want to plant bluejack, southern red or water oak for their high-fat acorns, says the University of Florida’s Institute of Food and Agricultural Sciences, or blackjack, willow or southern red oak for high-calorie acorns.

Become a Wildlife Gardener with National Wildlife Federation. It’s free and you’ll get great wildlife gardening tips and learn how to certify your garden as an official habitat.