Thursday, 15 November 2018

Why Are Invasives So Bad?

photo of Phragmites also called common reed grass.

Phragmites creates stands so dense that wildlife cannot move though it.

For the past year, I have been fielding questions about conservation, biology and invasive species on the forum Quora. It gives me a chance to hear the questions and concerns that people have and give back to the community. Questions I think Conservation Digest readers might be interested in have found their way into the FAQ section of this website.

This question appeared last week. Below is my response. After reading it, I hope you see what motivated me to create the website and write this blog.

Invasive garlic mustard, honeysuckle and buckthorn have all but wiped out spring wildflowers from the woodlands of southern Wisconsin. Japanese knotweed crowds out everything along stream banks where it becomes established. Wild parsnip causes serious chemical burns when the sap gets onto the skin. Cattails take over wetlands reducing open water for waterfowl and displacing the native sedge, reeds and wetland wildflowers. Phragmites (common reed) creates such dense stands that waterfowl cannot use the wetland.

Those four sentences capture a small portion of the problems caused by invasive plants that plague natural areas in Wisconsin. They only begin to scratch the surface of the issues created by invasive species.

Check out our new webpage About Invasive Species to learn more about the problem and how to prevent new invaders from getting a foothold in Wisconsin.

Tuesday, 13 November 2018

About Invasive Species

photo of Phragmites also called common reed grass.

Phragmites creates stands so dense that wildlife cannot move though it.

It can be really confusing when people talk about invasive species. What exactly are they and why should I care? These questions are especially important for landowners because invasive plants, and to a lesser extent invasive animals, can cause real and lasting damage. Because many of them have been around for years, a property owner may not even know they these unwanted guests or why they pose a problem.

Picture of common buckthorn leaves

Common buckthorn branch. Photo credit: University of Georgia.

Problem Plants

Invasive garlic mustard, honeysuckle and buckthorn have all but wiped out spring wildflowers from the woodlands of southern Wisconsin. Japanese knotweed crowds out everything along stream banks where it becomes established. Wild parsnip causes serious chemical burns when the sap gets onto the skin. Cattails take over wetlands reducing open water for waterfowl and displacing the native sedge, reeds and wetland wildflowers. Phragmites (common reed) creates such dense stands that waterfowl cannot use the wetland.

Those four sentences capture a small portion of the problems caused by invasive plants that plague natural areas in Wisconsin. They only begin to scratch the surface of the issues created by invasive species.

Staying with plants for a moment, think about how many millions of dollars farmers and ranchers spend every year controlling weeds. They pass along those costs to us in the price of our food. Pesticide drift causes both economic and health threats to farm workers and neighbors. Chemical residues are a problem for consumers.

Picture of zebra mussels.

Zebra mussels colony. Photo credit: USDA

Not Just Weeds

Moving past invasive plants, Zebra mussels cause millions of dollars of damage to power plant systems while reducing the electricity they can generate. Those same invasive mollusks consume the available food for native insects and shell fish causing the base of the food chain to collapse. The lakes they invade turn into water deserts.

Those who grew up in Wisconsin before 1975 will remember the curse of alewife. They are a small invasive fish whose populations exploded in the 1960s. Alewife consumed all the small fish and insects that form the bottom of the food chain. That effectively destroyed the commercial lake trout fishery in Lake Michigan. Fish biologists fought over how to control them and settled on introducing Coho salmon to the great lakes. While coho reduced the alewife and created a new game fishery, native lake trout stocks have not recovered as hoped.

Emerald ash borer (EAB) is an invasive beetle that is destroying  Wisconsin’s green ash trees. Homeowners, public works departments and park managers planted millions of green ash trees over the past half century. That makes them one of the most popular trees on the urban Wisconsin landscape. Whole neighborhoods to lost their terrace trees to EAB. Many parks have gaping holes in their shade canopies.

The emerald ash borer is also wiping out the native black ash, which Native American tribes in Wisconsin call basket wood. Ho Chunk woven wood baskets are purchased by collectors around the world. The loss of black ash means an important cultural and economic resource disappears from the state.

Long History

Invasive species are nothing new. Farmers introduced sheep to northern Wisconsin during World War II. Sheep brought with them a liver fluke that nearly wiped out the white tailed deer population in those counties. Dutch elm disease swept through Wisconsin in the 1960s doing away with a large percentage of our native elm trees. Recently, the pest has returned to attack many of those trees it missed the first time, as well as their offspring.

As long as people get on planes and ships, moving around the world and bringing living stuff with them, the threat for bad things happening will be there. Sometimes invaders are introduced on purpose because the they pose is not understood. Other times pest species sneak in as weed seed in grain, or insect eggs in pallets.

Picture of Asian longhorn beetle on human finger.

Asian longhorn beetle. Photo credit: USDA

Solutions Are Simple But Difficult

There is a way to stop them from becoming a serious problem. The key is early detection and eradication. In 1998, Asian longhorn beetles were discovered on the north side of Chicago. This is a pest that kills maples and other trees in genus Acer. The black and white beetle spreads with amazing speed. The beetles were traced back to pallets that arrived from China that were delivered to a local hardware distributor. Local officials jumped into action and in what was seen by some as over reaction, cut down 1,500 in northeastern Illinois. This quick response stopped the invasion in its tracks, so that by 2003 there were no new infestations.

Be Part of the Solution

You can help. Check out the Wisconsin DNR invasive species website and learn how you can identify them. Report suspicious plants or pests to the DNR using their reporting website. Citizen science is becoming popular in the state. The Wisconsin Early Detection Network is a program of the UW Extension Weed Science program. It encourages landowners to actively get involved in locating and reporting new invaders. The DNR will eradicate prohibited species preventing major problems.

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January 2018

Sunday, 21 January 2018

Great Brush Pile Burning

Author with leaf blower brush pile burning in the background.

There is more to burning a brush pile than dousing it with gasoline and throwing a match at it.

Mid winter is a great time for brush piles burning in Wisconsin. My wife Anette and I unpack the Forrester: first the sled; then the leaf blower, pump sprayer and torch fuel. Fill the chainsaw with gas and bar oil. No need to bring along extra as the saw will see limited work today. Some snacks, tea and juice will keep us happy through the upcoming afternoon. Finally, I tuck some dry kindling and a roll of old construction prints what will be our starter.

A mid January thaw during last week put the burn day in doubt. Forecast snow on Sunday night meant plenty of snow cover for the Martin Luther King holiday and our brush burning. A moderate snow, light winds and weather in the twenties meant we will be comfortable all afternoon.

The sled is half full and that is just fine with me. Anette grabs the rake closes up the car are we leave the county highway behind. The local snowmobile club came through this fall after harvest and dragged a beautify trail across the corn stubble. Access to the Vermont creek will be quick and smooth. I throw the rope across my shoulder and make fast work of getting to the easement.

Our first brush pile was made during two days work in early and late fall. The pile is made up almost entirely of honeysuckle and buckthorn with a couple small boxelders for good measure. The first task is blowing the snow off the pile and clearing a small ring around the pile.

It takes one calorie to raise the temperature of one pound of liquid water one degree Fahrenheit. To melt that same pound of ice to liquid water requires 36,150 calories of heat. To take that pound of water from 32 degrees to its boiling point requires a mere 180 calories of heat. However, to boil off that heat and drive it out from soaking wet wood require a colossal 241,765 calories. This is called the latent heat of melting and the latent heat of evaporation.

That frozen wet wood on my burn pile needs to thaw out heat up and drive off its water, then continue up to the 700 degrees needed for wood to Ignite. Now consider that there is a cold wind trying to carry off the precious heat from my fire. No wonder it is so hard to get a brush pile to burn in the dead of winter.

Blowing the snow from the pile and around it suddenly makes a lot of sense. So does bringing along paper and dry kindling. These will make sure I have fuel that can easily light and stay burning long enough to dry our surrounding wood in the pile.

Torch fuel is a two to one mix of diesel fuel and gasoline. Diesel has a low ignition point but a high flash point which makes it much safer to work with than straight gasoline.

A wise friend finally put me straight about using accelerants on brush piles. “You don’t want the torch fuel to burn. You want the torch fuel to make the wood burn. Let it set there for ten minutes and see what difference it makes.” He was right! All my life I would pour fuel on a pile and light it, never understanding that the fuel was sitting on top of the wood and burning itself off without heating up the wood enough to get it to ignite.

Now I pour on a quart where I would have used a gallon. By walking away for ten of fifteen minutes, the diesel has time to soak into the wood. There is no big whoosh of flame, instead the dry kindling and paper take off and heat up the surrounding wood that is ready and raring to burn.

Snow on the ground means embers will not ignite surrounding vegetation, making it safe for a couple of people to burn several piles at once. Many towns are weary of issuing burn permits in the spring and fall when dry grass and leaves make spot fires from brush piles a real danger. Winter burn permits are easy to get and are easy to watch.

Anette keeps vigil using the rake to push remaining branches from the edges into the coals where they are quickly consumed.

I head upstream to a downed tree that needs to be cut and stacked. It takes a half hour to get the pile set, but because this is a black walnut that is not yet finished drying out, our efforts to burn the pile meet frustration. After several failed attempts, it is time to move on to a third pile.

Like the first pile this is one has plenty of honeysuckle, which burns easily, buckthorn that burns okay when dry and preheated, and boxelder that has laid there for several years. As this large tightly packed pile springs to life, Anette breaks out cookies, chocolate hot tea. The snow is flying all around; we relax and enjoy the now fading sun as it forces itself through the snow and cloud cover.

As the sun begins to fade, I once again take out the leaf blower. There is a large bed of coals and large sections of trunk burning in the middle of the fire. There remains plenty of brush around the downwind edge of the pile that I am in a hurry to dispatch. Braving the smoke, I rake the remaining unburned fuel into the hot center where it sits listlessly. The small pile seems to be waiting for an invitation to burn.

So I supply just such an invitation. My leaf blower comes out of the sled and springs to life. Its supercharges stream of air turns the bed of coals into a blazing forge. The coals become furious and through intense flames and heat that make short work of the remaining branches that threatened moment earlier to suffocate the those same coals.

A few minutes running around the edge of the fire with the leaf blower moves the mixture of snow, leaves and twigs at the margin out into the snowy barren reaches beyond. A wide patch of charcoal black mineral soil now separates the two worlds and provides a safe barrier for the remaining wood to finish consuming itself.

We pull back across the field and wipe off the snow from the bottom of the sled. It slides into the back of the Subaru as the last rays of sunlight fade.

 

2017

September 2017

Friday, 01 September 2017

Labor Day Resolution: Work Smarter, Not Harder

As Labor Day weekend approaches, my father’s admonition to “work smarter, not harder” comes back to me. I was talking with a friend last week and he mentioned that they had begun pulling buckthorn on their newly acquired property in Columbia County.

There is no other way to say it; pulling buckthorn is hard work. In the following days, I thought about the many buckthorn projects that dot my past twenty years of conservation work in Wisconsin. Along with the blisters and sore muscles came hard earned experience that changed the way I look at habitat restoration in general and buckthorn clearing in particular. First is to avoid the “activity trap.” We see a problem and want to tackle it head on.

More to the point, we see the most obvious problem and take it on with the first or only tool we know. Years ago I learned that being successful means doing right things right. That means before doing anything, it is important to know that you are doing the right thing.

Doing the right thing can only happen once you have looked at the situation strategically. Why do you own a substantial piece of property? Usually there are several reasons, such as: having access to productive hunting land, getting away from urban life, giving your children an opportunity to learn about nature, or secure long-term income from forest crops.

If one of those reasons is that you want to preserve the natural heritage of your property, then protecting native plants and getting rid of invasive weeds and brush are important goals.

It might not jump out at you right away, but the best way to achieve those goals is to preserve and protect the good stuff first. None of us has enough money to do everything at right now. Once you ensure the best pieces of your land stay in good shape, you can take on the lower quality sections. Using this strategy makes sure the whole property stays at least as good next year as it was last year and hopefully a little better.

With a prioritized list of tasks, you will know you are doing the right things … and in the right order.

Then you are ready to decide whether you are doing things the right way. If there ever was an case of, “when all you have is a hammer, everything looks like a nail,” pulling buckthorn is it. There are a range of methods for removing buckthorn, pulling is the most tedious and labor intensive.

Buckthorn produces both male and female trees. Once they are mature, male trees produce pollen while the female trees produce fruit with seeds. So, when it is time to tackle that big stand of buckthorn, the first targets should be the mature female trees.

A wise man told me that, “when you dug yourself a hole up to your neck, for heaven’s sake put down the shovel.” Buckthorn seed is viable for more than seven years; so the sooner you eliminate the seed producer trees, the sooner you will start running out the clock on that seed bank.

Clearly, mature buckthorn trees are too big to pull with anything but a bulldozer, so we are talking chainsaw work. Cut trees as close to the ground. This will prevent tripping hazards and damage to equipment once the grasses and wildflowers grow up. Treat stumps with Triclopry at the cut stump rate on the label. Add dye to the solution so you can see where you spray. Use a small hand sprayer and only apply the herbicide to the outer ring of the stump where the sapwood is found. This will save you a lot of chemical and limit collateral damage.

If you are cutting this fall, haul and stack the trees in the tightest brush piles you can manage. Run your chainsaw through the brush pile to reduce the size because this will make the piles burn much easier. Burn the brush piles once there is snow on the ground. The wood will have had time to dry out and snow will prevent embers from starting a wildfire.

After the first snow is also a good time to spread seed for next spring. Once you open up the soil by removing the buckthorn, you will be amazed at how quickly things pop there next year. Chief among the spouts will be baby buckthorn seeds. If you do not get native seeds started, you will end up with a stand of new buckthorn even more dense than what was there before.

Because there will be buckthorn seedlings sprouting up next year, consider doing a controlled burn of that section of property in the following fall after the summer grasses and wildflowers go dormant. Fire will kill the new buckthorn seedlings which will still be green but will not harm the native plants that will already be sleeping for the winter.

To my friends getting started on their new property; best of luck and enjoy the journey. Hope these insights will help you see more success sooner. Stepping back and getting to know your land and playing out your plans into the future will allow you to make better decisions and achieve your goals.