Thursday, November 29, 2012

A view of the oldest living thing on the University of Illinois campus

A view of the oldest living thing on the University of Illinois campus

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One of the perks of my position with the School of Earth, Society, and Environment at the U of I is an office in the Natural History Building on Green Street. My colleagues and I will be moving to temporary quarters soon as renovations here begin, but for now the view out my window includes a magnificent bur oak, a tree I used to cross campus just to check on now and then. [Photo by author.]

How big is “magnificent”? I recently measured my tree at 13’7” around at chest height, which makes it bigger than just about any other tree on campus, although that’s still on the small side compared to the Illinois state champion bur oak, which is more than 23 feet in circumference. In characteristic bur oak fashion, my tree’s massive lower limbs grow almost horizontally; by my measurement, conducted in cooperation with coworker Lana Holben, they span 114 feet at their widest point.

It can be difficult to know for certain how long a tree has lived, but last year Gene Himelick, Professor Emeritus of Plant Pathology at the U of I, calculated that my tree is between 183 and 188 years old.
As bur oaks go, 180-some years is no record—they may live to be three or four hundred—but that still makes this one the oldest living organism on campus. (Insert your own joke about old professors here if you must.)

Like others of its kind, my oak provides all manner of benefits to wildlife. Squirrels feast on its abundant acorns, and they build their leafy nests among its limbs. Migrating songbirds also flock to it, attracted by the caterpillars of moths and butterflies it hosts. Among the many birds that distracted me from work this past spring were American redstarts and blackburnian warblers, blue-headed vireos and ruby-crowned kinglets.

This year’s extraordinarily warm March prompted my oak to flower and leaf out four weeks earlier than normal, which means the birds found a diminished food source when they arrived on schedule in late April and early May. An occasional warm spring won’t undo the age-old association between oaks in the Midwest and the long-distance bird migrants that depend on them, but ornithologists anticipate that the long-term trend toward earlier leaf-out could have that effect, to the great detriment of the birds.

Bur oaks were the signature tree of the wooded groves that here and there graced the landscape of east central Illinois when tallgrass prairie was the dominant landcover. Their thick, corky bark, which grows on even their smallest branches, enabled them to survive prairie fires better than other trees.

The species name for bur oak, “macrocarpa,” translates as big seed, and refers to the size of its acorns, which can be two inches long. The “bur” in the common name refers to another characteristic of the acorns, their heavily fringed caps, which reminded people of chestnut burs.

In one of my favorite tree books, twentieth-century botanist and writer Donald Culross Peattie cites studies suggesting the root system of a bur oak mirrors its above-ground growth in its mass and extent. If that’s so, the parking lots near my tree are already encroaching on its roots. But I know it has friends, too; someone from Facilities & Services kept it well-watered through the drought this summer. Similar consideration for this natural treasure will be important as construction to bring the Natural History Building up to date begins.

Thursday, November 15, 2012

Now may be the time for DIY solar power in east central Illinois

Now may be the time for DIY solar power in east central Illinois

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Have you ever entertained the idea of generating electricity at home with solar panels on your roof? If so, now may be the time to act. That’s the conclusion Phil Krein reached recently, anyway. He’s a long-time resident of central Champaign and a professor in the U of I Department of Electrical and Computer Engineering, a guy who knows this stuff as well as anyone around.

Why now? Previously, says Krein, installing solar panels was a job that required either a knowledgeable, dedicated hobbyist with lots of time, or a specially trained contractor. But that’s not the case anymore.

The availability of two fairly simple new technologies has emboldened Krein to go ahead with his own do-it-yourself project. One is a high-quality, self-sealing screw for mounting the brackets to hold solar panels on a roof.

[Phil Krein on the roof of his garage; one screw in, twenty-three to go. Photo by author.]

The other is a photovoltaic panel that comes with its own small inverter attached to the back. The inverter converts the direct current produced by the panel to alternating current, which can be fed into the grid. That makes the system safe for a nonexpert to work with and easy to expand. Formerly, most photovoltaic panel setups depended on a single, larger inverter, which required a more complex electrical setup.

In addition to these technologies, the other incentive for Krein to go ahead with solar now is the extremely low price of photovoltaic panels. For comparison, about four years ago the best-priced panels cost more than $5 per watt, or $1200 for a 240-watt panel, and that was down from $9 per watt in 2007. The panels Krein just purchased are priced at $1.57 per watt, or $378 per panel plus $30 each for shipping. (They're AC Unison PM240PA0 panels, which you can see on the list at 

He ordered them via the Web on a Monday and they were delivered to his house three days later.

Krein’s expenses for the project total about $3280, which breaks down as follows:
$2448 for six solar panels; $540 for the optional monitoring box that watches their performance; $150 for mounting hardware and electrical bits and pieces; $50 for a new two-way electric meter; and $80 for an electrical permit.  This doesn’t take into account the federal tax credit for residential solar projects or state incentives that can be sought.

In the current phase of the project Krein is installing six panels. Together they’ll produce about 2400 kilowatt-hours of electricity over the course of a year. That’s about 30 percent of what his family uses, and, at current prices, a savings of roughly $20 a month. That may not sound like much, and Krein’s project may take ten years or so to pay for itself, but as he points out, “The warranty is 25 years, so I don’t have to think about it again until it is time to replace the roof.”

That would already make it a reasonable deal, but Krein thinks there’s no reason to believe the panels will not continue to function for far longer—possibly fifty years. You can call that anything you like, but I call it cheap, non carbon emitting, non air polluting, non water polluting, non land occupying electricity.

Thursday, November 08, 2012

Danville nature photographer “captures” unusual amphibian

Danville nature photographer “captures” unusual amphibian

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Have you ever seen a siren? I don’t mean one of temptresses of Greek myth, or the thing that makes noise atop an emergency vehicle. I mean the amphibian called a siren. It’s an eel-like creature that’s actually a salamander. As adults, sirens get more than two feet long. They’re somewhat variable in color, but mostly dark, and they have two undersized front legs (but no rear legs) and external gills.

Like most residents of east central Illinois, I’ve never seen a siren. But Jessica Runner of Danville has, and not a mile from her home. Here’s how.

Runner is a busy mother of two young boys who manages the shoe department at Carson’s and owns a landscaping business with her husband. But she is also a dedicated birder who has cultivated a growing passion for nature photography in recent years.

Often when Runner has time off work she drops by Heron Park, which is at the north end of Lake Vermilion and just minutes from her home by car. Its wetland complex makes an excellent spot for birding, and it hosts a rookery where great blue herons nest.

One morning at the end of May this year as Runner approached the park in her car she spotted a great blue heron stalking a meal in a shallow pond that borders the road. She quickly pulled over, and, using the car for a blind, photographed the bird over a period of 40 minutes as it worked to procure breakfast.

Great blue herons are patient hunters. They avoid spooking prey by moving extremely slowly until they’re close enough to stab it with a quick extension of the neck.

Unfortunately for Runner, her own patience did not quite match the heron’s, and her attention was focused on a family of wood ducks at the moment it struck. To her delight, however, the heron ran back toward her with its still-wriggling prize, and she was able to photograph the bird’s battle to subdue it.

[Photo of great blue heron with siren by Jessica Runner, used with permission.]

As she took pictures, Runner thought she was seeing her bird kill and then eat a snake. But when she later saw the images on a computer screen, she realized the snake-like creature had legs, so she forwarded them to a friend in Urbana. He identified it as a siren.

Runner wasn’t the only person excited about her discovery. She contacted Chris Phillips at the Illinois Natural History Survey to tell him about her pictures, since the Survey’s Field Guide to Amphibians and Reptiles of Illinois shows no records for sirens in Vermilion County.

“It goes to show you,” Phillips said, “there are still some surprises out there for a herpetologist in the Midwest.”

On one hand, he continued, it seems odd that sirens would turn up in Vermilion County because they are more common in the southern part of the state and along major rivers. Besides, he and other field scientists have studied the reptiles and amphibians of Vermilion County for decades and never been able to find sirens there before.

On the other hand, it’s also a potential boon to have them located where they’re so accessible for study by UI faculty and students. “It’s only a forty minute drive from campus,” he pointed out, “and during high water we could throw a trap into that pond right from the truck.”

Sirens are weird creatures, and there is much to be learned about them. They maintain throughout life characteristics that most amphibians lose as adults: they continue to live in water, they keep their external gills and they develop only tiny front legs.

They can survive prolonged dry periods by encasing themselves in slime that forms an airtight sac and going dormant, but for how long, nobody knows. Nor have scientists ever witnessed their courtship and mating, so they can only speculate about that based on the siren’s physical characteristics.

I suppose there are people for whom the discovery of an unexpected amphibian nearby causes no excitement, but I’m not among them. As the temperatures warm next summer, I look forward to helping catch sirens at Heron Park. Don’t worry if you’re not there, I’ll take pictures.