Friday, May 25, 2007

More Invasive Species Musings

Today, I met a customer who a number of years ago, trusting our nursery to steer her towards quality plants, purchased a novel introduction that we were marketing. Today she is waging war and justifiably upset that she must spend time and resources to reclaim her garden from Polygonum cuspidatum, which was sold to her under the name Fallopia japonica. [picture from USDA]

This is the story of the traditional market driven need for the latest and the newest. Each year we look for the latest, newest car design; the newest refrigerator in the latest shade of white; the most recent designed shoe from Milan, and the novel flower introduction from exotica. New sells, and new drive our market economy; selling the newest potentially invasive returns to haunt.

On the issue of invasive species, as with many ideas in the world, I find myself a radical moderate. When all the stakeholders think that I hold incorrect views, I suspect that I have found the middle of the controversy. And from the middle, I seek to weigh the information from all sides and to establish a working compromise with as many stakeholders as I can find. There are those who would say that the issue of invasive species is simple and straightforward, and that my attempt at moderation is counterproductive for all non natives must be removed and no new introductions be allowed to settle. And there are those who say, let the market decide, stay out of the way.
The small delightful reptile sold to a young person for a few dollars grows up to be a 200 pound Burmese python. It seems, after having met the snake close up and personal, that sales without limit are problematic at best. And one can make the case based upon most people's fear of snakes that sales should be severely restricted. This restriction is much harder to do with a flower which grows under almost any condition and blooms from late spring to frost almost anywhere in the US - Lythrum. And yet the snake and the flower have some similarities below the surface.
As I have written before, the wicked inconvenience of invasive species rests upon the underlying aggregation of complexities that ensnare those who consider on the surface issue. Invasive species issues are four dimensional, but much of the discussion is only one of place; time is not included. Many who sincerely try to rescue and restore our last remaining natural areas are trapped by focusing on the small/fast interactions of a self sustaining ecosystem such is found when Japanese knotweed terrorizes a garden or natural area. The very nature of the large/slow interactions which, when one attempts to forecast, are beyond our human temporal horizon and therefore at best are present fact supported conjectures leads quite often to argument without the possibility of end.

Because invasive species are a wicked problem, there is no end, and the inconvenience that results from defining the problem from one’s end goal leads to stakeholders talking past each other rather than with each other. Those who would plant only natives in urban settings are perforce looking to the past to determine the palette of natives. They are assuming that in the changing dynamics of a disturbed area, the natives of the past will thrive. They are attempting to return us to a “pristine” setting. This description itself is simplistic, for at a more complex level, the native only stakeholder is attempting to garden a self-sustaining ecosystem.

Another feature of a wicked problem is that there is usually a coequal, co-evolving wicked problem that increases the complexities of understanding. In the case of invasive species, the coequal problem is climate change. What is native today will be moving up and north as the temperatures rise, and new natives will be making inroads in our natural areas. We must always beware of native to when and where.

Invasive species, however, call for action. I use the poor analogy of weeds in an ornamental garden which must be continuously addressed or the garden (system) will certainly crash. As we garden we learn which plants “work” together, and which are to be avoided. It seems to me that the same outlook applies to natural areas. Those who traffic in living organisms have a responsibility to supply as much information about a species as possible to the end user including possible negative effects on the local environment.

Should we sell invasive species? For the past decade, we have tried to find a middle path. We long ago discontinued sales of Lythrum unilaterally, but we still sell English ivy. We post warning signs on the ivy, barberry, miscanthus, and euonymus, and have recently stopped selling all types of “Bradford” pears. We feature “Baysafe” plants, a term we trade-marked (native to the mid Atlantic) and try to educate the consumer to the right choice. To say there is no problem is manifestly wrong to me; to dictate based on changing science and understanding to the consumer is counter intuitive to a member of the merchant class. How we define a beautiful landscape must begin to include a sense of beauty beheld in a working ecosystem.

1 comment:

Graham Rice said...

I don't get your point about your nursery selling Japanese knotweed to a customer who was then angry that it took over her garden. Although it's unfortunate that Japanese knotweed has had a number of botanical names over the decades it's not exactly news that it's name is now settled at Fallopia japonica. And can't the nursery staff recognize Japanese knotweed when they see it? And who put it in a pot and gave it a tag in the first place? Your propagator? A wholesale grower? So a new plant arrives... does no one bother to find out anything about it? Sorry, but the nursery is 100% to blame.

I'm extremely sceptical about much of the hysteria surrounding invasives, but any nursery selling Japanese knotweed, even the variegated form, should take full responsibility for the consequences. So what did the nursery do for the customer?