Thursday, February 24, 2005

Miscanthus, an Energy Crop for Illinois?

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Could Illinois agriculture someday produce a crop that would be burned to generate electricity? A group of researchers led by plant biologist Steve Long at the U of I thinks so. Building on studies and practical experience with biomass power generation in northern Europe, they are investigating the economic and environmental potential of growing Miscanthus x giganteus as an energy crop in the American Midwest.

Miscanthus is a perennial grass indigenous to East Asia, known most widely by its many ornamental forms, which grow in tall clumps and produce long, feathery flowers. The type of Miscanthus being investigated for use as an energy crop in Illinois is a stronger-stemmed, highly productive hybrid that attains a height of eight to twelve feet over the course of the growing season.

Miscanthus x giganteus is a sterile cross of two naturally occurring species, which is propagated by means of rhizomes. Unlike some ornamental varieties, which have escaped and become invasive, Miscanthus x giganteus does not set viable seed, and so is not a threat to native plant communities. (If you’re wary of such claims you might rest easier knowing they are substantiated by thirty years of experience with this type of Miscanthus in Denmark.)

For use as an energy crop, the annual growth of Miscanthus is left standing in the field to dry, and can be harvested from November into February, using the same machinery that is used to harvest corn. It is then bundled and fired in combination with coal. One of the benefits of burning Miscanthus to generate electricity in Illinois is that doing so would alleviate the need for power plants to import low sulfur coal from out of state in order to meet emissions standards, as they currently do.

From an environmental perspective, Miscanthus appears to hold a number of advantages over row crops such as corn and soybeans. As a perennial, it is established with a single planting operation, as opposed to the yearly tillage and planting required for annual crops. This greatly reduces soil compaction and erosion, and eliminates the costs and energy use associated with planting every year. Miscanthus also improves soil by adding large quantities of organic matter to it.

Added benefits accrue from the fact that Miscanthus is low input crop. It requires little to no herbicide once it is established because it comes up early in the spring and grows so thickly that it simply out competes weeds. It requires little or no fertilizer because it recycles nutrients back to its roots at the end of the growing season. And Miscanthus grows well even in dry conditions, which would likely obviate the need for irrigation.

Environmental benefits aside, the question for potential growers of Miscanthus will be whether they can make money doing it--and the answer to that question appears to be yes. In fact, the U of I team calculates that over a ten year period, and without subsidies to either system, Miscanthus production could be more profitable than a rotation of corn and soybeans, especially in parts of the state where corn and beans are least viable.

Thursday, February 17, 2005

Insect Recyclers and Insect Fear Film Festival

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This Saturday the U of I’s Entomology Graduate Student Association will host the 22nd annual Insect Fear Film Festival, an event designed to get us thinking about bugs without dwelling on ways to kill them. The focus of this year’s festival will be forensic entomology, the science of using insect evidence in legal matters.

If you’re a fan of the television show CSI, or a reader of crime stories you know that often this means determining when a murder was committed by observing the development of the insect larvae found in the victim’s body.

Of course the insect larvae that most interest forensic entomologists are only a subset of the tiny critters that perform the ecologically essential work of recycling dead animals.

In the natural world, the death of an animal larger than a mouse triggers a fascinating and complex process.

The body is typically first discovered by adult blow flies—blue bottles, green bottles, or black—which, depending on factors such as weather and the accessibility of the corpse, may arrive on the scene within ten minutes of death, attracted by odors we cannot perceive. Blow flies quickly lay their eggs in wounds or the body’s natural openings. Within a day, these eggs will hatch and the larval flies—better known as maggots—will immediately begin to feed.

The next insect arrivals at a corpse are a second wave of flies, the flesh flies. To compensate for their somewhat later arrival, flesh flies deposit larvae that have already hatched within their own bodies, rather than eggs, on the corpse.

In his book, What Good Are Bugs?, retired U of I entomologist Gilbert Waldbauer notes that the presence or absence of flies makes an enormous difference in the length of time it takes for a corpse to decay. “Without them,” he writes, “a carcass decomposes very slowly and retains its form for months. If flies are present, 90 percent of the available soft tissue on the carcass is gone within 6 days.”

Maggots do not occupy a decomposing corpse alone for long, however. Other insects that feed directly on the body, such as carrion beetles, soon join them, as do predacious insects—various ants, wasps, and beetles—which come to make a meal of the maggots themselves. If you’ll pardon the expression, it’s a dog eat dog world down there!

As the soft tissue available on the corpse dwindles, two species of checkered beetles, which specialize in eating dried flesh, move in. These are also know as “ham beetles,” because they are just as happy dining on cured meats that humans produce—like bacon or ham—as food they find in the wild.

Finally, a few highly specialized forms of lice, beetles, and moths, move in to recycle even the materials that are indigestible for the rest of the animal world, feathers, claws, and hair.

Now, to some people it may seem gross to dwell too long on insects at all, let alone the insects that recycle dead animals. But if you want to get really really gross, you’ve got to think about where we would be without flies and their allies in decomposition.

Thursday, February 10, 2005

Salamanders in Spring

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Spring may seem a long way off if you buy the groundhog’s prediction about six more weeks of winter, or focus on the meteorologist’s warnings about the big snow that we’re bound to get sooner or later. But spring comes in by degrees, not all at once, and the cardinals and Carolina wrens in our area began to sing about it more than a week ago already.

Indeed, the very next heavy rains will likely trigger one of the coolest and most ancient natural phenomenon that still takes place in east central Illinois, the annual congregation of amphibians in the waters where they breed.

The participants in this aquatic love fest, which starts out in water cold enough to send people into shock, include frogs and toads, but to me the most interesting are the salamanders, especially the eight species known collectively as mole salamanders. In Champaign county this group is represented by two kinds: the smallmouth salamander, a black, or very dark brown creature with gray markings on its sides that give it a marbled appearance, and the eastern tiger salamander, which may grow to be a foot long, and which sports yellow spots that stretch out to cover more and more of its body as it ages.

You may or may not have been aware of it, but the eastern tiger salamander was elected by schoolchildren to be the official state amphibian of Illinois in a 2004 contest sponsored by Lieutenant Governor Pat Quinn.

As their group name suggests, mole salamanders spend most of the year beneath rotting logs or underground. There they move about in natural gaps, and the tunnels and burrows created by small mammals, feeding on a variety of invertebrates including earthworms, slugs, and insects.

Beginning sometime in February, however, as the earth thaws and the ice recedes, rainy nights bring mole salamanders above ground, and they trundle overland seeking out the vernal pools where they were born. These are wetlands that hold water far enough into the summer for amphibian larvae to mature, but which dry up at some point in most years so that fish cannot survive in them.

If you were to shine a light into such a pool on a spring night--somewhere in a wooded area with a stream nearby--you’d be amazed at how many salamanders you can see, and surprised at how gracefully they swim.

During the day, you may see salamander eggs, held together in a mass with a jelly-like substance, and attached to twigs or other underwater structure. The larvae will hatch in four to seven weeks, and live in the pool until autumn, when they metamorphose and move onto land.

But maybe this is looking too far ahead. After all, those first spring rains haven’t arrived just yet.

Thursday, February 03, 2005

Illinois Armadillos?

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We’ve grown accustomed to the alarms raised when a new species of animal makes its way into Illinois, and in most cases with good reason. Creatures like the Asian longhorned beetle and the Bighead carp wreak havoc on ecosystems and threaten our economy. But there’s a newcomer to the southern part of our state that seems to be stirring up more curiosity than eradication plans--the nine-banded armadillo.

Nine-banded armadillos are the most numerous and widely distributed of the twenty species of armadillos that exist today, and the only kind that inhabit the United States. They are native to South and Central America, but they’ve been expanding their range for at least the past hundred and fifty years. They were first reported north of the Rio Grande in Texas in 1849 and have steadily spread north and east from there. During the early part of the twentieth century, another population of armadillos was established in Florida when they were brought there by people and released. That population also spread rapidly and converged with the Texas population in northern Florida and southern Georgia in the 1970s. Armadillos now also occupy parts of South Carolina, much of Alabama, Mississippi, Oklahoma, southern Kansas, Arkansas, western Tennessee, and southern Missouri. Individuals have even been reported as far north as Nebraska.

Will Illinois be added to the list of states that armadillos call home? People have reported seeing them here since the 1970s, but a flurry of sightings in recent years has prompted Joyce Hofmann and colleagues at the Illinois Natural History Survey to look into the issue.

With support from the Illinois Wildlife Preservation fund, they surveyed 135 people familiar with the animal life of southern Illinois and solicited reports of armadillo sightings by birderwatchers. Respondents reported 76 different armadillo records from 22 counties between 1999 and 2003, mostly in the western half of southern Illinois. There were also reports in 2004 from seven additional counties.

How armadillos arrive in Illinois is an open question. They might be brought by people and released, as they were in Florida. Or they might come as stowaways in cargo on barges, trains, or trucks. Or they might arrive on their own power walking across bridges, or--unlikely though it may be--even somehow crossing the Mississippi river.

Although we know that armadillos can get to Illinois, we don’t yet know whether or how well they might become established here. Cold will eventually stop their spread north, since they can’t hibernate and depend for food on insects and other creatures they find by digging in the earth. Where the ground stays frozen for too many days in a row during winter they are unable to dig for food and can’t survive. The current prediction for their northern limit is a line that runs across the state about a third of the way up from the bottom.

Whether or not armadillos become Illinois residents, they are fascinating for their many quirks.

When they are startled, armadillos may jump four feet into the air, and they are surprisingly fast for such ungainly looking creatures.

Armadillos don’t float naturally, so they cross small bodies of water by walking across the bottom, like divers wearing weights. When they must swim, they can make themselves buoyant by gulping air to partially inflate their intestines.

Armadillos typically give birth to identical quadruplets every year, and they can delay pregnancy at the earliest stages to ensure that young will not be born until weather conditions are favorable.

And of course, armadillos are the only North American mammals that grow their own armor.

If you happen to see an armadillo in Illinois, make a note of the date and location and contact the Illinois Natural History Survey. You’ll be contributing detail to a unique ecological success story.