Chipmunks and Groundhogs and Bugs, OH MY!!

kw: book reviews, nonfiction, natural history, ecology

I have two microscopes. One is the kind you see in CSI or other shows portraying science labs: high-power (25x to 1600x), uses glass slides with thin slices of something (usually a crucial clue). So, I have an array of glass slides, cover slips, stains, razor and other blades for slicing stuff really thin, and various light-source accessories like filters and dark field attachments. I use it to look at pollen, slices of leaves & twigs, the critters in my birdbath water or nearby stream, and such. But it can be a bit of a pain to use.

The other is easier to use. It used to be called a Stereo Inspection Microscope. It is really two microscopes, one for each eye. It is low power, from about 5x to 30x, and you just put a light of some kind next to its tray and plop something there to look at. You'd be surprised at the features of a 2mm-size brown grease ant stuck to some flypaper, at 30x, in 3D. It looks over two inches long, and the little facets on its eyes are like jewels, there are hundreds of tiny hairs all over, and its jaws resemble a mini-bear trap.

So when I picked up Suburban Safari: A Year on the Lawn by Hannah Holmes a few days ago, with its cover showing a big plastic toy ant facing down a lawnmower, I expected a lot of insect ecology. I've read Ms Holmes before, particularly The Secret Life of Dust, and I enjoy her writing. Based on reading Dust, I also expected a healthy dollop of environmentalism, and was not disappointed.

Holmes gives us a jaunty journal of her peregrinations through a 0.2-acre yard over a year's time. The extensive bibliography that closes the book shows she didn't spend the whole time bug- and bird-watching. She gets into things.

She also names things. Cheeky, the chipmunk that visited her all spring and half the summer (lured by sunflower seeds in a cup on her desk), Yawp the juvenile crow, Big Fat Mamma the ground hog (or wood chuck or whistle pig, depending where you live), and Stunky the skunk move purposefully through the narrative. I don't recall that she named any insects.

One might expect someone with a strong environmental bent to abstain from interspecies murder. That is a caricature; environmentalism is a cost-benefit-driven pursuit. In the interests of getting her house insulated, and retaining the insulation's integrity, she must eliminate a number of wasp nests and a family of wall-dwelling mice. Ms Holmes wishes to go on living, and with a modicum of comfort, at minimal environmental cost.

Insulating the walls is a big, big step. A 1917 house with a few inches of matted fiberglass in an attic, and wholly empty frame walls, probably requires twice the fuel, compared to the same house with blow-in filling the walls and a foot or so in the attic.

And she has her dislikes, mainly introduced species, which, she notes, comprise 3/4 of the species in her yard and neighborhood, from European and Asian grasses and weeds to starlings and English sparrows (really a little finch), to the Euro-Asian dogs most commonly chosen as pets. The "native American" dog is most like today's Carolina dog, which looks a lot like a Dingo.

The lives of critters fascinated me most. Crows don't just "caw", each has its own voice, with more or fewer syllables, tone and duration variations (caw-caw-caw ... caaaAAW ... 4 caws on a rising note, etc.). Squirrels and even wasps have their own personalities.

As I read through the book, it was evident that the content of natural history was decreasing as that of environmental exposition rose. The last three chapters are fully environmental. And it was here that I found something to chew on. She reports that Jeffrey S. Dukes, now of the University of Massachusetts, published an article in which he reports that for each gallon of petroleum we consume, ninety metric tons (98 short tons of the 2,000 lb. variety) of plant matter were initially buried in the earth (Dukes, J.S. 2003. Burning buried sunshine: human consumption of ancient solar energy. Climatic Change, 61(1-2): 31-44.). I found the article and had a look.

The conversion of buried plant matter to coal or petroleum has several stages. Coal production is more efficient: about 85% of the carbon gets back to the atmosphere as peat is formed, and another 4% as brown coal is formed. That means 11% remains. Then more is lost when brown coal is converted to anthracite, in which less than 7% remains. OK, a ton of coal started out as ten to fifteen tons of carbon in tree trunks and leaves, maybe thirty or forty tons of newly-buried trees. Remember, this is the more efficient process!

Most petroleum formed from algae and softer plants that grow in water, whether fresh or ocean (the sweetest crudes were from fresh-water algae). As best I can read the figure on the fifth page of the article (p 35 in Climatic Change v61), here is the breakdown: [this is a list; I have trouble making html tables]

• Kerogen formation: 98% lost, 2% remains.
• Kerogen to Petroleum: about 50% efficient, so a little over 1% remains.
• Much escapes to the surface (85%) before being trapped, leaving 0.15%.
• Only a third of liquid petroleum can be recovered, so we extract an amount equal to 0.05% of the original plant matter carbon (Dr. Dukes's illustration is less generous, showing only about 6% of trapped oil extracted, for an overall recovery of 0.0085%. I've worked for an oil company, and know the real figures).

So, a ton of carbon (eight or ten tons of buried, wet algae) eventually produces either 1 pound (my recovery calculation) or 0.17 pounds (Dr. Duke's calculation) of extracted petroleum. A gallon of liquid petroleum weighs from 7 to 8.5 pounds and is 86% carbon by weight, so let's say a gallon of light crude has 7 pounds (slightly heavy crude). That gallon started out as either seven tons of carbon in 70 tons of algae, or about 40 tons of carbon in about 400 tons of algae.

To compare with coal by the ton, a ton of C is the content of 286 gallons of crude.

OK, there you have the range. Clearly, we'd do better in the long run—20 to 120 times better!—finding and mining kerogen, and then cooking oil out of it. That is why the "oil" shale in Utah and Wyoming and the tar sands in southern Canada are such important resources. A gallon of oil extracted from oil shale is the remnant of only a couple of tons of initial plant matter, rather than 70-400 tons.

One side drawback to using the oil shale, from a rockhound's perspective. The Green River shale, one of the better kerogen sources, has the best fish fossils in the world. I'd hate to see them go up in smoke...

Back to the book. Hannah Holmes is a thoughtful, thought-provoking writer. My environmentalism is not quite so hair-trigger as hers (and I don't deify Amory Lovins as she does). Regardless, I greatly enjoy reading such well-researched and -written work.