Thursday, August 08, 2013

Accepting Defeat - as a strategy toward victory

The battle against invasive species is a new phase in ecosystem conservation. The depth of our strategy and analysis is still shallow. We have done a better job at raising the war cry than at planning the campaigns.

“Obscene, in fetid patches clustered,
Defiant stood the garlic mustard …”

Thus began a poem by then North Branch poet laureate Jim Cutler. In the early days, garlic mustard and wild parsnip seemed daunting. At one point chest-high sweet clover filled all the major openings of Somme Prairie Grove. Today it’s largely gone, as are the evil clover and parsnip.

Back in the daunting days, we wondered at times whether to fight or give up on various species. Kentucky bluegrass was everywhere, but its actual impact seemed modest. We ignored it. It’s fading out.

For a while we pulled wild carrot. But it wasn’t our top priority, and we noticed that it went away on its own within a few years wherever we didn’t have time for it, so we stopped wasting troops on carrot.

When we started, this was all buckthorn. We pulled the alien Japanese hedge parsley here – to make sure
that the native species could find spaces to thrive. Was that work necessary? Or were we wasting our time?
Some of us waged campaigns against thistle. But restored plant diversity defeated it too without our help. We now ignore it. Yes, I cringe when there’s a flair-up in a newly brush-cleared area. But I know it will be mostly gone in two years or four.  We devote our thistle time to more important things – like gathering seed.

But what do we do when unfamiliar new “invasives” show up? Potential invaders present a different sort of challenge. When Japanese hedge parsley appeared, we worried. We studied in in the scientific literature without learning much. We looked nearby and found areas where it seemed to have taken over completely. We thought: perhaps the best solution is to eliminate it quick, while there are just a few plants. To ignore a new, possibly scary species – which may or may not turn out to be harmless – is a gamble.

We had made that gamble wrong – with white sweet clover. Just a few plants at first, we ignored them. Soon the dastardly stuff was waist-high over many acres. Grrrr.

Then sweet clover became a nightmare. We scythed, pulled, and taxed people’s backs. It challenged our energy and resolve at the hottest time of the year. I remember episodes of heat stroke and chiropractor bills. But we beat it, and it’s mostly gone.

I now wonder if we perhaps made the wrong choice with Japanese thicket parsley (Torilis japonica). In that case, we made the opposite gamble. We tried to wipe it out. It even had its own poem:


That’s the whole poem, a sub-haiku by North Branch steward Laurel Ross. We hated the nasty little parsley for many years. Worse than sweet clover, it hides in the shrubby edges where the mosquitoes are the thickest. Even worse, unlike sweet clover and garlic mustard, which we could just dump in out-of-the-way piles, this menace clings to animals, which then bring it everywhere. I stuffed it into bags, saved them in the garage, 
Japanese parsley, the white stuff here, seemed ready to totally invade.

and burned the evil mess in bonfires when summer weed-pulling season gave way to fall and winter brush-cutting.

After two decades of annual mid-summer hard work, in 2012 we gave up on Torilis. Was that decision a wise strategic retreat? I shudder a bit as we face our eco-reality check over the next few years.

This year I find it luxuriant in many places. Much thicker than ever. Next year I anticipate it will be worse still. And yet I have some confidence it will fade away to very little over time. Yes, it will fester for a while where new brush has been cut and the ecosystem is an open wound for a few years – while diversity builds from our planted seeds.

But over the years, Torilis seems to have revealed itself as a Georgy-Porgy that only does its mischief against weaklings. “When the big boys come out to play” – if it could – it would run away. Instead it strangles, starves and dies against the better-adapted competition.

I found the battle hard to give up. We had put so many years of agony into combating it, just in case. We were successfully holding the worst populations at bay. But we weren’t coming even close to wiping it out from the site. And it was occupying our time.

A strategic retreat seemed best. We accepted defeat in a battle – with some confidence that the larger war would go better if we focused our forces more wisely.

Teasel, crown vetch, purple loosestrife, reed canary grass – these are serious killers of rare ecosystems. We now battle the last of them at Somme with all our might – unencumbered by trivial visions of victory over Torilis.

As with human medicine, the diagnoses and prescriptions we use in restoration are partly art and judgment. Priorities and assessments change. We learn, and many of our ecosystem patients get healthier, richer, and more beautiful by the year.