Thursday, November 19, 2009

A Book Review: The Earth Moved

I'm going to do something different and post a book review I wrote. This is a book about worms. "WORMS?" you say! Yes, "worms," I reply.
What is there worth knowing about worms? What could possibly interest the general face-book addict about worms? Read this book review and find out.

The Earth Moved: On the Remarkable Achievements of Earthworms by Amy Stewart (Chapel Hill: Algonquin Books, 2004), 223 pages.

Tat Tvam Asi,” or “Thou Art That,” teach the Vedas. I had this drummed into me in school, as I minored in Religious Studies as an undergrad. That is a scary enough thought when you think of all the sad people in the world; but is downright disturbing when you are mincing an earthworm. I spent many sleepless nights thinking that, if time is an eternal spiral and not a continuum, my consciousness will experience every lifetime lived by everyone ever. So someday my consciousness will experience Paris Hilton’s life. And countless times my consciousness will endure the fate of the earthworm, brought on by salamander keepers everywhere, as I am sliced, diced, chopped, minced, severed, and hacked up into bite-sized pieces to feed to our precious salamanders and newts. Worms are nature's perfect newt food. Sweet Dreams.

What got me thinking in this vein? The Earth Moved, by Amy Stewart. Before I read this book, an earthworm was a spineless, senseless, inconsequential, puny…well…worm. Now, an earthworm is a mover and a shaker, a transformer of landscapes, forests, and even of civilizations. Why would I willingly read a book about earthworms? Because a friend of mine said, “I really enjoyed reading this book!” And now I have really enjoyed reading this book too. I was interested to read it because I wanted to try to grow the kind of worms I find in my backyard, the kind my own newts prefer, which seem to be neither nightcrawlers nor red wigglers. This is not a book about growing worms, but much much more.

Written in an accessible, but even better, an engaging and interesting style, I learned that Charles Darwin devoted the last years of his life to the study of worms. They are that interesting. If you go in your backyard and dig up worms, you will find several species. And they will probably all be invaders. Many common North American worms are not native, but were introduced by European settlers. They spread faster than they would have naturally, on their own. On their own, they travel only a few meters a year, taking approximately 100 years to travel a quarter mile. But with the spread of European plants and crops and farmers across the country, nurseries, fishermen dumping their unused live bait, and ATVers, they are in all parts of the US. Why is this significant? The introduction of earthworms into forests has changed the whole landscape of the forest--by eating the leaf layer. Forgive me for quoting at length, but it was so fascinating, and I think we should all learn about this. So here goes:

"Earthworms…can--and do—consume the entire leaf fall of a forest in a single season. Small plants and tree seedlings flourish in the damp, slowly decaying layer of forest floor. This layer, the duff, is built up over many years. It contains leaves and other organic matter in all stages of decay. Many of the native plants that once flourished in the forest produce seeds that have intricate germination strategies. A seed might take two or three years to germinate, going through a complicated cycle that depends on this spongy duff layer. Now that the forest floor is bare, most small plants have simply disappeared. 'We’ve seen a loss of eighty to ninety percent of all understory plants in some areas,' [said a researcher from the university of Minnesota]. 'That’s where we find the most earthworms. They just expand their population to fit the available food source. They multiply until there are enough of them to eat all the leaf litter on the soil’s surface. And the ten or twenty percent of plants that do survive? The deer get those (p. 100-101)."

It doesn’t just affect the trees and plants, either:

"As worms come into the forest, we see a shift from voles and shrews to mice. There are all kinds of frogs and other amphibians that live in that duff layer. And there’s even a ground warbler that nests in the forest floor.... It’s hard to believe that a creature as small as an earthworm could push…birds and animals out of a forest, but this is exactly what they think is happening. That’s not all: insects that live in the duff layer—including microscopic creatures such as springtails---may be disappearing before they have even been identified and described. The change in soil texture could lead to erosion, especially in the summer when water runs across hard, bare ground in sheets. Even the composition of the soil can change; the presence of earthworms can lead to an increase in bacteria and a decrease in fungi populations, which could in turn affect which plant types proliferate and which struggle or fail entirely. I looked up at the bare branches high above me. How could an earthworm push something as enormous as a tree out of the forest?…I thought about the logging protests in the redwood forests back home [Eureka, CA], and the tree sitters living high in the canopy. The fight to save those forests happens aboveground. It is a battle for the part of the forest that we can see: branches, leaves, tree trunks. But the fate of this forest in Minnesota lies entirely with the part of the forest we can’t see: the dark underground (pp. 106-107)."

Despite this plague on the forests, worms are invaluable to farming and creating fertile soil. The potential for earthworms has barely been explored. Some types of worms promote the growth of certain plants, by producing beneficial bacteria or inhibiting certain plant diseases. Worm castings (poop) greatly improve crop yield. Earthworms aerate and transform the soil. It has been claimed that the fertile soil created by earthworms is responsible for the development of great civilizations—if people are well fed, society is freed up to develop math, science, language, and even build pyramids.
Worms are as beneficial as they are destructive. Earthworms are even one way of studying continental drift. Why did Pangaea break up? Because earthworms bit the continents apart.

OK, I made that last bit up, but earthworm distribution records the movements of the continents in a way that above-ground animals cannot. And even I couldn't have made that up. They are also important in waste management, and their workings can facilitate detoxification of polluted soils. They can also process raw sewage into acceptable fertilizer. Furthermore, earthworms are a useful biomonitor, telling us what pollutants are in the soil in the first place. People who raise newts are familiar with the concept of limb regeneration (a lost arm or leg will GROW BACK!!), but newts can't hold a candle to the regenerative power of earthworms. They have a lot to teach us. Although, as I said, it is not really a book about growing earthworms, I learned what I needed to know about raising and keeping the type of earthworm in my backyard that I want. Different types of earthworms eat different things and live in different ways, and I think I’m well on my way to being able to supply yard worms to my salamanders next winter.

While I was reading this book, I was greatly troubled to learn that worms apparently enjoy being stroked, that it makes them relax. In my turmoil, I emailed the friend who told me about the book. “What, then, separates them from, say, ferrets, except that I will use scissors to mince worms, and I wouldn't do that to my ferrets? How can I continue to chop them up? Do you have this trouble?” Would my guilty conscience force me to give up keeping newts?

No. Thank you, Jen, for talking me off of that bridge. She sent me a link which explained that, according to studies, it is just a stimulus-response reaction, and not an emotional one.
The power of worms can’t be underestimated, and this book is the perfect place to learn about them. It was more than educational, it was inspiring. Here is a sentence that I never thought that I would write: earthworms are awesome!

Available on Amazon starting at $6.66--cheaper new than used!

1 comment:

Abrahm said...

Sounds neat! I may have to peruse Half Price books for this or pick up a copy at the library. It's amazing what even the lowliest creature has to offer the world :)