Monday, February 28, 2011

Bright Spots in Winter: BGR #37

If winter's lingering a little too long where you are, you can always turn to the Berry-Go-Round for a touch of life and color. The Phytophactor has corraled a red-carpet-runway-free batch of plant posts for this month's carnival.

Contemplate invasive (?) orchids (we should have such weeds) or bryophytes-du-jour (such as this loverly liverwort), explore tasty wild edibles (with care!), tropical vines, or Great Basin conifers. You can even try your hand at making soup—but brush up on your Latin first to get the ingredients right...

And of course, FF's own lichen post below is featured too.

Thanks, Phactor!


Saturday, February 26, 2011

Opposites Attract, or What’s Up with Lichens

What is it about lichens that’s so fascinating?? I caught “the bug” many years ago, but I guess unless you’re exposed, your immunity remains intact. Once you start noticing them, though, they can be hard to resist.


First, there’s the startling array of shapes and colors. That trait they have in common with other fungi so maybe it’s not lichens’ most unusual feature (those are fungi, above, by the way). Still, for everything from barely perceptible crusts to wacky forms worthy of a sci-fi movie, lichens are hard to beat.

Second, they’re pretty much everywhere. Once you start spotting them, you can find them in deserts or high mountains and everywhere in between, growing on rocks, old stumps, tree bark or twigs, mosses, soil, or substrates provided by humans. Some even live underwater.

And everywhen. Fossil lichens have now been reported as far back as 600 million years ago (in China, 2005), and it’s been proposed (though not widely accepted) that the famous Ediacaran biota of Australia may have represented fossilized lichens (Retallack, 1994; refuted by Waggoner, 1995). They’ve even been given credit for, very early on, building the oxygen atmosphere and making the planet fit for habitation.

Okay maybe that’s a stretch… and probably we should call them "lichen-like symbioses" rather than the lichens we know today. There is, however, an "unequivocal report" of lichen fossils from 400 million years ago, and that's not half bad.

Lichens are tough. Studying them in the harsh environment of the Arizona desert, where they’re lucky to get a few minutes to photosynthesize using dew at dawn before they dry out for another day, one develops a certain respect for these crusty critters. Imagine the temperature on a dark volcanic rock at midday of an Arizona summer... you'd be crustose too.

Lichens survive in the even harsher Namib and Negev deserts, where dew and fog are the only sources of water. We used to speculate that, if there was life on Mars, it was most likely in the form of lichens.

That latter hypothesis has since gotten a boost from actual research. As reported in New Scientist, 2005:

In an experiment led by Leopoldo Sancho from the Complutense University of Madrid, two species of lichen—Rhizocarpon geographicum and Xanthoria elegans—were sealed in a capsule and launched on a Russian Soyuz rocket on 31 May 2005.

Once in Earth orbit, the lid of the container opened and the samples were exposed to the space environment for nearly 15 days before the lid resealed and the capsule returned to Earth.

The lichens were subjected to the vacuum of space and to temperatures ranging from—20°C on the night side of the Earth, to 20°C on the sunlit side.

We just knew it!! When the lichens came home from their jaunt in space, and were returned to reasonable conditions, they came back to life and actively metabolized, just as if they hadn't been subjected to intense solar radiation and a huge range of temperatures, not to mention absolute vacuum. They have remarkable recuperative powers.

By the way, that temperature has got to be wrong; space is no where near that warm!! According to Answers.com, "In Earth orbit, the temperature of objects in sunlight can rise to 120°C/250°F. The actual temperature in space is about 3°K (-270°C or three degrees Celsius above Absolute Zero)."

That's literally cool, but what about the attraction?

Maybe the neatest thing about these incredible organisms is that they're not one organism at all, but a combination. The lichen symbiosis is not unique, but has happened many times, and with many different partners. Now that fungi, and therefore lichens, are no longer considered plants but their own entire kingdom as are algae, the lichen combination unites members of two extremely distinct groups of organisms. (Ever think it's tough to get along with mates of our own species?? Consider the lichen.) The photobiont consists of algal or cyanobacterial cells immersed in the hyphal strands of the mycobiont, or fungal partner. Here's a great orange lichen; note the green layer of algal cells in the lower right of the photo, where the thallus has been cut.

Above: Xanthomendoza mendozae close-up. Photo by Chris Wagner, U.S. Forest Service. By the way, the Forest Service has a well-written section on lichens; worth checking out for more on the basics!

In some lichen species, the symbiosis gets really interesting. They may have a primary union with, say, Trebouxia, the most common green alga in lichens, but they also have a little cyanobacterial thing going on. Take this Peltigera for example. When wet, its bright green color tells us that most of the thallus contains green algal cells (Chlorophytes, eukaryotes). But see those darker bumps on the surface? Called cephalodia, those harbor cyanobacteria (Protists, kingdom Monera), adding a third kingdom to this particular symbiotic union.

In our neck of the woods (Pelts are creatures of the forest-floor), most Peltigera species are grayish or brown and never show green, even when wet. Those species, including the abundant Peltigera canina, have remained true to their original cyanobacterial commitment.

Back with more on these wonderful beings soon!


Saturday, February 19, 2011

Brown is Back: the February Thaw

This week, brown is the new white. Most of the evidence of the storms of early February has disappeared from the view, if not from the north-facing front yard.

The rainbarrels were 350-lb ice cubes little more than a week ago, but with temperatures in and above the 40s and 50s since the 11th, they’ve returned to liquidity. Tonight the chance of precipitation moves a bit above slim, so white may make a return as temps are expected to be more seasonal than springlike tomorrow.

Meanwhile, it’s a comfortable 52 degrees at midday, and Cat Woman and I are going to attempt to revisit the jelly lichens at the Bear's Lair this afternoon.

Inspired by Swamp Things and her photos of spring (snakes? salamanders?... mink??) already, I went out to look. Even the currants (usually first) are resisting the temptation to show green, but I did spot some early leaves of grape hyacinths, so the bulbs are considering a new season.


Friday, February 18, 2011

What We're Used To

Yesterday I had another of those startling encounters with a "foreign" culture when someone visited from downtown Denver to install equipment. Really a nice guy, but he always has trouble finding the place even though he's been out here before (we're 20 miles from Denver). To get here, after exiting the highway, you have to make all of three turns, all on paved roads. More than getting lost, though, I was surprised by his concern that he might encounter a snake. Not just a rattlesnake, but apparently any kind of snake.

It's February. I explained that his chances of seeing a snake were somewhere between extremely slim and zilch, no matter how mild the day. We also talked about bears and mountain lions, neither of which I've seen in person in my 30 years here. We know they're here, we just don't see 'em. In fact, we've grown used to not seeing 'em. (Photo by H. Barrison via Wikipedia.)

We don't live in a remote mountain cabin without services. This is, for all intents and purposes, civilization. There are neighbors within shouting distance; we even have regular trash pickup. But when I thought about the "other foot"—how I feel when I go to downtown Denver—I got it. It's culture shock; it just wasn't what he was used to. I can function downtown, more or less, and he can function here; it's just outside of the comfort zone.

In fact, I can navigate fairly well downtown, as long as I'm going somewhere I'm used to. But set me down in San Francisco or St. Louis, and I'm a fish out of water. Big cities make me nervous; if I went to New York City, I'd turn into a basket case utterly dependent on my guide. There would have to be a guide. (Photo adapted from Wikipedia.)

I had the same experience decades ago when I was in college. I tutored a young man from The City who found himself unsettled by the surroundings of the rural college we attended. Drop him off the subway in the middle of Queens or Yonkers, he'd be fine. The green hills of upstate New York, though, freaked him out. I doubt he ever left the campus. As we talked about it, we realized I'd be equally freaked on his home turf.

We humans are adaptable creatures, and that's the problem. We're able to get used to whatever's around us, and it becomes a new norm, a new basis for future comparison. Scientists call it shifting baselines and Wikipedia does a pretty good job of explaining the basics. Originally applied to the oceans and perceptions of fish abundance, the concept works marvelously for just about everything. We can only compare with what we know. That's why the older we get, the more different the "good old days" look.

The message, I guess, is be careful what you get used to, whether it's the new superhighway, more convenient shopping, having 100 TV channels, or never seeing open lands and wildlife. It will end up in your future. Sci-fi writers have suggested that humans can adapt to planets and environments that are entirely manmade. At the rate we're going, some of us may get to find out.

Every day we all make choices, says a student at Scripps. Make sure your choices count.


Monday, February 07, 2011

The Week That Was: February So Far



January's last gasp was almost tropical, with clear skies and shirt-sleeve weather most of that last weekend. The groundhog brought change, for sure, this time! The cold started on the 31st, and we (and the groundhog) were in the deep freeze on his day, with the added touch of several inches of snow. Mind you, I'm not complaining (especially after lamenting December's lack of moisture in any form). I was lucky, I got to stay home feeding the woodstove and keeping the chickens in liquid water (or trying to) as we spent a couple days in the teens below zero.

The slideshow covers the past two weeks, starting with the brown views of late January, and ending with this morning's sun shining on a foot of new-fallen snow that began arriving yesterday morning. By 10 a.m., it will be above freezing and I won't have to worry so much about the chickens' thirst. Colorado blue skies have returned for the moment, though more snow is expected tonight and tomorrow.

I did worry about the birds, most of whom flocked to the feeders. Food was no problem; they had plenty of that, but I was out of suet. I invented a substitute of sorts, that immediately attracted a little Downy Woodpecker, but she soon lost interest. Even the starlings didn't find it tempting. Finally, I fed it to the more appreciative chickens, once proper bird suet arrived.

I tried to provide the little birds with water too, but it was rejected. Juncos, finches, and assorted sparrows foraged inches from the dishes without indulging. Everyone looked like little puffballs, all fluffed against the cold.

Both Sharp-shinned and Cooper's Hawks have also been coming by regularly. (I'm finally getting better at telling them apart, at least when the size differential is visible.) I've found little evidence of their success, but they keep the little birds on their toes.