Rainy Days Are Good for Blogging!

"Native" Dawn Redwood (Metasequoia glyptostroboides)

So I had one resolution on this rainy, dreary Sunday in the Mid-Atlantic:  Finish up my invasive tree/plant/ shrub presentation for my Watershed class!  I think it's pretty good, if i say so myself (See below).  Taking pictures around my neighborhood for a couple of weeks and putting this presentation together made me aware once more what a challenge invasive species pose just in my small neighborhood of Waycroft-Woodlawn.  Right now, porcelainberry and amur honeysuckle are in their fruiting glory and the local birdlife is gorging and (inadvertently) spreading these invaders.  It's also amazing how invasive and non-native species seem to be all around us and how insidious the spread of these species has been.  No doubt, part of the success of these species has been our human propensity to not be aware of the threat they pose and our own desire for the latest exotic, maintenance free, and sweet-smelling "thing" that nobody else (yet) has.  For example, how many people would be aware that crape myrtle, camellias, the ubiquitous evergreen azaleas, and most commercially-available hydrangea are not native to the US?   While none of these are considered invasive, English Ivy, Porcelainberry and Amur Honeysuckle (profiled in my presentation) all got their start in the same way--they were introduced as hardy ornamentals and for erosion control.  The result, a seeming monoculture of introduced non-natives and a pronounced loss of biodiversity.

So why did I post the above image of the Dawn Redwood (about 30 meters tall now) that sits in my front yard?  Partly to show the complexity of deciding what is native, non-native, and what is invasive.  The Dawn Redwood was a native of North America and spread across most of the continent before it became extinct here thousands of years ago.  In the 1940s, it was rediscovered in a remote part of Szechuan province in China and soon thereafter reintroduced in the United States.  it is now fairly widespread in the Mid-Atlantic and spreads quite readily in these parts--in my own yard, literally hundreds of seedlings sprout every spring from the mother tree and they are very fast growing once established.  A lovely tree, especially in winter when its reddish bark is  one of the most colorful in an otherwise brown landscape of bare trees and snow, I wonder if someday we'll decide that its hardiness, long-term absence from the North American ecosystem, and its effect on other natives will render it as yet another on the long list of invasives that bedevil us.  INVASIVES PRESENTATION