Wednesday, August 20, 2008

8/20/08: WHAT'S AN INVASIVE?


Wednesday, 7:30 AM. 58 degrees, wind W, calm. The channel is calm. There is considerable haze over the Island and on the eastern horizon, The barometer is down, predicting partly cloudy weather.
At this time of year I get many questions about the pictured plant, Tamarix ramosissima, native to southeastern Europe and central Asia. There have been a number of them planted in Bayfield because of their pink blossoms and unusual appearance.
It is highly tolerant of saline soils and very useful in that regard for planting on ocean shores and along roadsides that get a lot of winter salting. Unfortunately this renders it highly invasive in the US southwestern deserts.
All of which brings up an interesting question; it does not seem to be invasive elsewhere, so when and where should a plant be labeled and banned as an invasive species? If it is planted here, can it escape from here to the southwestern deserts? But, to be the devil’s advocate, might it escape to our Great Lakes sand dunes? I have heard that the common Lilac is invasive on Manitoulin Island in Lake Huron; does that mean Lilacs should be banned in Toronto and Detroit? Kentucky bluegrass is invasive in native prairies; should we not have lawns and ball fields? And, how do you legislate against things that are already here and part of the landscape (sounds like immigration, doesn’t it)?
The whole subject of invasive species is complicated philosophically, scientifically and practically. It is also important from a regulatory standpoint, since Big Brother (the federal government) and the Little Brothers (the states) are much engaged in passing legislation on these matters, and there are high-pressure groups on both sides, actively lobbying. This is a divisive topic. Keep your ear close to the rail on this one.