Terraforming Earth

Thinking about terraforming barren, alien rock worlds has made me a tad obsessive about the lessons we can learn from remediation and restoration of the native terrain here on Earth.  Native plant popularizers like Douglas Tallamy or wilding proponents like Isabella Tree may not be thinking about space settlement, but I am.  So I’m reading a lot of strange things.

The Interstellar Research Group is looking at what kind of experiments would be useful for creating arable soil out of the Martian regolith.  The papers the IRG is finding are dense but interesting.  I belong to a Facebook group devoted to getting rid of invasive plants.  It is there I learn how to hate.  (Actually, I don’t hate enough.  After an hour of pulling garlic mustard I get depressed about killing plants and have to go transplant wood aster from the fenced backyard where it flourishes to the front where the deer will eat it– or plant something new.)  Now, I’ve just finished reading Isabella Tree’s dense, fascinating, magical, and inspiring book Wilding.  It was glorious.

I have just two caveats and a couple thoughts on its applicability to terraforming.

The book. Unlike my beloved science fiction, the world building in Wilding takes place in real life.  An English couple, the writer Isabella Tree and her husband, Charles Burrell, have converted 3500 acres of Knepp Farm in Sussex to wild space, fencing in the fields, adding grazers and browsers like deer, ponies, and pigs, and letting nature take its course.

What they produced was a successful experiment that showed that the theories pushed by conventional conservationists fall short of what can happen when nature gets to take back the land on its own.  Apparently, conservationists in the UK (the U.S., too?) try to manage areas of special interest to protect a single species.  This results in very little good for the purported beneficiary and not much good at all for the rest.

Instead of following the conventional approach, the Burrells adopted the pioneering practices of Frans Vera, a Dutch ecologist who employs megafauna (deer, horses, etc) to prevent wild areas from turning into forests.  Forests are good, sure, but they don’t offer much diversity in the way of ecological services for different species.  The megafauna’s presence keeps the saplings down and ensures variety in the landscape, so there’s water, meadows, scrubland, and a host of offerings, including large standing oaks free to spread and age for centuries.

The Burrells had to work hard to sit on their hands.  As former farmers, they watched in horror as thistle took over huge areas.  But they held tight, and were rewarded for it.  Out of Africa came the painted lady butterfly in the thousands to feast, gorge, and breed on all that thistle.  The butterfly herd weakened the thistle and the dread plant never returned in such numbers, but the Burrells still have it for the butterfly.  The book is full of story after story like this, and the statistics in support.

It also offers an interesting glimpse of history.  The understated British way of saying it is that “they were on short rations during World War II.”  In reality, they were running out of food, so the government mandated that all land be farmed.  Meadows were plowed, forests were razed, and almost everything was turned to farmland as the Dig for Victory program sought to ensure the island wouldn’t starve.

The government poured subsidies onto the farmers.  It was great for what the writer calls “cereal” farming (perhaps she means grains, in American English?) to feed the population. It was so great, that many farmers lobbied for the subsidies to continue even after the war ended.  But the newly tidy landscape was not so great for wildlife.  The UK has seen plunges in bird and butterfly populations, never mind actual extinctions.   Now, the nightingale and the turtle dove have reappeared at the Burrell’s farm.  The painted lady butterfly flourishes.  Fallow deer roam free.

Like I said, it’s inspiring.

Caveats.  Just two small wishes for the book being even better.  I wish Tree had spent a paragraph on the importance of native plants.  Her passing references aren’t enough.  Entomologist Douglas Tallamy observes that something like 90 percent of insects, including caterpillars, eat only one plant—the one they evolved with.  If that’s not in the landscape, you won’t have that insect, caterpillar, or butterfly.  Then you won’t have food for birds, because birds need the protein and fat they get from caterpillars and other insects.  Hence, the decline of the nightingale and turtledove in England.

The failure to highlight the importance of natives feeds into my second concern.  Tree and her husband had 3500 acres to transform.  The rest of us mostly don’t.  A paragraph or three mentioning that individual homeowners can contribute to the restoration of dwindling populations would have been useful.  Even if we aren’t going to invite wild pigs into our back yards, we can plant flowers, bushes, and trees native to our region to feed all those hyper-picky insects, caterpillars, and butterflies, and thus birds as well.

Sure, it would be great if more large farms went the wilding route, but it would also be great if individuals did their bit.  We could, for example, stop gardening with plants from other continents and regions.  The non-natives just starve the wildlife, not to mention the dire consequences that result when non-natives jump the fence, get into parks and forests, and turn invasive.

In the mid-Atlantic of the United States we can plant viburnums, which offer flowers for pollinators and high fat berries for migrating birds.  We can nurture the native pokeweed.  When allowed to grow to ten feet, it looks like something out of Star Trek, the original series.  It, too, offers both flowers and berries.  We can sow milkweed seeds for the monarch’s caterpillars.  We can do so very much more.  The internet is a marvelous thing, and super useful for finding what’s native to one’s own region.

Terraforming.  Despite Wilding’s fascinating tale, it doesn’t actually offer precise instructions for achieving the same goals on other worlds.  For one thing, a planet orbiting an alien sun won’t have a seed bank of Earth plants. It won’t have hedgerows acting as miniature arks to repopulate the landscape.  It won’t have the bacteria and fungi lying dormant in the soil that we still have.  We’ll have to bring everything with us.

But it does have some lessons in the role each portion of the ecosystem plays in success.  When I first started gardening I didn’t worry about the soil.  (I know.  I know.  Hush.).  Then, obviously, I had to.  I learned about mycorrhizal fungus, bacteria, nematodes, all of that.  Then I learned about the picky insects last year.  Who knew?  Now Wilding teaches of the importance of megafauna for ensuring diversity in the landscape:  beavers for water management, pigs for open spaces, deer for keeping things down (admittedly, given the ravages deer bring to my front yard, this one’s emotionally hard).  Next, I’ll learn that humans play a role.

In the meantime, I’m going to go back to wondering whether I should open the gate to my fenced backyard to let the deer in for a few days.  Maybe they’ll take out the non-native hydrangea I planted before I started terraforming .

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