Monthly Archives: September 2013

Do Insects Flee First Frost by Flying High?

The other night, many of the colder parts of Vermont had their first frost. Our garden didn’t quite freeze, sparing the beans for another week or two, but I found this frost at the rest stop in Randolph:

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Before I went to bed Monday night I was looking at the RadarScope weather radar app (highly worth the money if you want a good weather radar app) and noticed an odd area of radar returns. I didn’t get a snapshot, but took one Tuesday night when the phenomena repeated.

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I was curious. The night was completely clear a half hour earlier, so I knew it wasn’t raining or snowing. I pulled up the “Hydrometeor Classification” view, in which the new dual-polarization radar is able to determine the type of precipitation that is falling. This indicated neither rain nor snow, but instead mostly “biological” echoes – flying animals of some sort.

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I fell asleep without thinking much more about this, but the next morning I saw this interesting paragraph in the technical forecast discussion:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
627 AM EDT TUE SEP 17 2013

INTERESTING THAT THE DOPPLER RADARS AROUND THE REGION CONTINUE TO
PICKUP RATHER HIGH RETURNS OF 20-30 DBZ NEAR THE FREEZING LEVEL
ALOFT AT 2-3K FT NEAR BTV AND DUALPOL ALGORITHMS INDICATING MOSTLY
BIOLOGICAL RETURNS THINKING MAINLY INSECTS. VAD WINDS RATHER
UNIFORM AT 25-45 KNOTS FROM 1K TO 6K FT.

For us, the possibility of an early frost means covering any still-living garden plants with an old curtain and taking the wood furnace for a test run. For many organisms, including many plants and insects, the first frost is the last day of life. Hopefully before the frost they have had the time and energy to create enough eggs and seeds to overwinter. An early frost potentially means the loss of several weeks of growing, mating, laying eggs, and the other things organisms frantically try to finish in the early fall. This week, for instance, highs are forecast to hit the mid to upper 70s for the next two days, and no temperatures below 40 are forecast for at least the next seven. If there were a way to survive one or two nights of early frost, insects would get at least a week of extra time…

Early and late frosts tend to form during clear, dry, mostly calm nights where cold air can sink into hollows. Montpelier and Barre did not freeze because river valley fog covered the valley like a blanket, but many areas above the fog such as the Montpelier Airport (actually in Berlin, Vermont) and the previously mentioned rest stop, did freeze. If you were to rise above the hollows and hills, however, you would remain above freezing until you reached the above mentioned freezing level of 2000 to 3000 feet.

I wonder if this is exactly what the insects were doing. It would take a lot of energy to spend hours hovered high above the ground, but if the alternative is death, it would be worth trying. If countless millions of insects were hovering above Vermont’s cold hollows on the last couple of chilly nights it seems likely that enough would survive to descend after morning light, and enjoy this last week of warm weather. These insects would lay more eggs than their deceased brethren, thus reinforcing the behavior in future generations.

Or maybe the flight of insects was unrelated. Maybe there was something wrong with the radar. I’m not sure, as I’ve never heard of insects flying above temperature inversions in early fall. If anyone does know, either way, I’d love to hear about it!

Destroying a Place Does Not Create a Desert

Last weekend I got to visit Cape Cod for the first time. It’s a beautiful landscape, and one about as different in natural setting from Vermont as you can get in a day’s drive. The cape is made of old glacial deposits dropped there at the peak of the last Ice Age, and rearranged since by wind and water. Despite fairly stormy conditions, very sandy soils don’t hold water, and only dry-loving species like pitch pine can survive.

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As with all of New England, Cape Cod’s recent ecological story has been one of heavy impacts by humans followed by a significant amount of recovery. Wet, warm summers and abundant water from winter snowpack allowed the forests to regrow in areas heavily impacted by humans, though of course these new forests are probably quite different from the ones that were here 500 years ago.

I came across a sign at an interpretive site that I found somewhat annoying. The title was something like “From Forest to Desert”. It described a landscape that European colonists stripped of lumber. This allowed the glacial sands beneath to form into large shifting dunes. While the area has since recovered to some extent, it was, at that time, ruined. A harsh, tired, battered landscape. A wasteland.

Not a desert.

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Cape Cod picks up, on average, 30 inches of precipitation a year. This is drier than much of New England but some three times as wet as the ‘wettest’ place that can be considered in a desert climate. It’s thirty times wetter than the driest part of the Mojave, in Death Valley. It’s also often insufferably humid, whereas the Mojave can easily reach the single digits of relative humidity. Most importantly, it was not at that time a functioning ecosystem. It is no more a desert than a playground sandbox is.


Image from Wikipedia: Creative Commons Licensed as Public Domain.

You see, a desert is a unique place… a harsh one, and one many humans have difficulty surviving in. But for those who look, it is a place of wonder. I feel pretty confident that the blowing wastes of post-colonial Cape Cod did not resonate with the intoxicating odor of sagebrush or creosote bush after every rain. Wanderers would not come across the astonishing tracks of a sidewinder rattlesnake. No cryptogrammic crust of tiny lichens held the soil. The crispness of a shadow on a summer day would be somewhat blurred.

Antelope Island

An approaching thunderstorm would be shrouded in haze and mist like all New England thunderstorms, rather than the bare skeletal elemental thunderstorms that eke out quick downpours and blasts of lightning over desert mountains. The places under Cape Cod thunderstorms do not burst forth a week or two later with a sudden extravagance of life.

The power of modern humans to create a functioning ecosystem is questionable. Destroying a place creates a wasteland.

Destroying a place does not make it a desert.

It’s time to do away with silly terms like “desertification”. These terms lead to a disregard that leads to destruction of some of our last true open spaces, the refugia of shamans and holy people and other such folk across the ages. Furthermore they sugar-coat our arrogant, foolish actions. Overgrazing a field creates an overgrazed field of weeds and dust, a ruined place. It does not create this:

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For those who think a desert is a wasteland, I challenge you to spend time in the desert. Not a day, a day in the desert offers such a rush of solitude and harsness that the body and mind often buck away. Spend a week, or better yet a month. Be safe, of course, but be curious. Poke about in a wash. Find a rattlesnake and watch it from afar. Sit on a peak on a hot light and watch lightning from a storm over 100 miles away. Drink water from a spring that has not seen sunlight since the Ice Age (it’s best to filter it if you aren’t sure, but that won’t take away its spirit). Sleep outside and wake up at 3 AM to see so many stars it appears the light has dark spots in it between the lights rather than the other way around.

And don’t say desertification. Don’t say ‘food desert’. Let’s call it what it is. Think of the most wasted, ruined place you can to refer to instead.

Suburbification has promise… but considering where they occur, “Food Suburb” is a bit recursive is it not?

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