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OUTDOORS: Is it time to re-think battle against invasive species?

Is the time and money being spent on current control methods really the best way to tackle the issue, wonders outdoors columnist
20210312_Tiny Marsh_Phrag (Hawke) (5)
Phragmite reeds are shown in an area marsh.

Ah, winter: that time of the year when all good field workers hunker down over piles of data sheets and screen shot after screen shot of last summer’s work.

Number crunching, data verifications, questioning where the field notes were filed, deciphering illegible scribbled notes that are underlined and followed by an exclamation point. Compiling, assimilating, compressing. Turning 205 pages of data into a three-page report that justifies your position’s existence.

This is also the time of year for conferences, those get-togethers with your peers to see how your work stands up against the others (provided you have your three-page report finalized), to network, to “get out of the office.”

But that has to be done virtually now, which is a drag, but very cost effective. No more travel, accommodation and meal expenses to be covered, now it’s just another day spent in front of the computer. No buffet lunch provided by a glamourous hotel, just a quick timeout for you to heat up yet another bowl of soup.

Despite my dismal sounding intro, these conferences are continuing (albeit virtually) and are important to attend. Some platforms operate like a real conference room with assigned ‘tables’ for intimate chats with colleagues prior to the keynote speaker dominating the bandwidth.

A couple days ago the Ontario Invasive Plant Council held a terrific gathering with about 150 people ‘attending’. Tech glitches were minimal, the speaker lineup was interesting and the topics on the agenda were, well, topical. And it was free to attend, thanks to some wonderful sponsors.

As the host name implies, this conference was all about invasive plant species: who’s doing what, which species are the newest threat, what’s new in control methods?

My personal summary of the day, in regards to the battle against the aggressive habitat-altering leafy newcomers might be stated as “ well, you win some and you lose some.”

Over the previous years, each conference seems to have had a default villainous adversary: purple loosestrife, garlic mustard, dog-strangling vine, buckthorn shrubs, and currently phragmites reed. Each of these species (and many more) are invading and conquering local habitats and are shifting the ecological functions and values of the site. The annual battle cry has been “They must be stopped!”

However, there are times when the first battle plan may not work, and the second battle plan may also fail. There is always the posturing that it should have worked but, you know, it didn’t. Yet herein is the value of these conferences… what can you learn from others? Was it the wrong control method? The wrong herbicide? The wrong time of year?

These setbacks are not the end of the war against invasives, yet are providing us with some real lessons about land management. There is a ‘re-think’ happening as to the feared presence and impact of these introduced species and their successful presence within the local woodlot.

Are they as bad as first thought?

The short answer is “well, yes, kind of.”

The challenge for anyone involved with land management is that future judgement of your work: “just what the heck were you thinking?” 

There have been innumerable studies conducted looking at the inter-relationships of all living things, a subject known as ecology. We think we know how the system works, and therefore try to make plans to ensure the local habitat stays functioning within those known values.

Land management planning includes the protection of some things and the elimination of other things.

I think it was ecologist John Riley who asked within his book The Once and Future Great Lakes Country (an excellent read, I might add) as to what era are we trying to maintain? Pre-European contact? The 1830s colonization era? The 1950s industrialization era? Or are we trying to go back to that fateful day when the most recent glacier melted away?

Therein lies the frustrating challenge to land managers… just what is it that we are trying to conserve? And that leads into the ‘re-think’ mentioned earlier.

Some ecologists are taking a step back to look at the bigger picture, the longer story. Not to ignore the impact of these troublesome plants, but to determine if they might be considered a plus to the landscape rather than an outright negative. Is the time and money being spent on current control methods really the best way to tackle the issue?

A couple examples from within the conference: a huge area of phragmites reed was sprayed with a herbicide using helicopters flying over a provincial park. After the plants died, tracked machines were brought in to crush the standing dead stems, and huge piles of dead phragmites stems were burned. The result? Not exactly as planned.

The phragmites reed was indeed all but wiped out in the control area. But the regrowth of the native plant species was much slower and less dense than hoped for. And the resulting open water now allowed for another invasive species, European Frog-bit, to flourish and contaminate the area. And there is no known cure for removing Frog-bit from our waterways. Ah, crap.

In an attempt to control another invasive, Japanese Knotweed, bug larvae were taken from Japan and reared in Canada. After about 17 years of rearing these little guys, generation after generation within laboratory conditions, it was approved to release them into the wild.

Two things happened: the wrens, chickadees and warblers ate most of them; and the survivors didn’t do as well, as they were conditioned to living in a lab not outside in the great outdoors. So back to Japan to capture and import new breeding stock.

Please do not interpret this column to be anti-control; I am still a supporter of finding ways to conserve existing biodiversity. But to win this battle, to maintain the landscape in some state of status quo… now requires time and insight to recalculate the impacts, effects and level of concern to be spent on invasive plant species.

And since it’s winter and cold outside, now is as good a time as ever to do some serious ‘navel gazing’ as to how best to manage the bit of natural landscape that remains.