Disappearing plants

A slide show in the online edition of the Boston Globe caught my eye last night. Studies have been done that indicate a substantial decline in the plant diversity at Walden Pond since the mid-1800s when Thoreau decided to "live simply" at the pond (I believe on land owned by Emerson, in fact). After poking around a bit more, this is what I've discovered:

• Over the past 100 years, the average temperature in Massachusetts has increased by 4.3 degrees Fahrenheit.
  
• 27 % of the plant species that Thoreau documented are extinct, at least locally
  
• An additional 36% of plant species at Walden are classified as having a imminent disappearance
• The plant species that remain are the plants that have been able to adjust their flowering time, on average, 7 days earlier than 100 years ago; the plants that were unable to shift have died off, at least locally.

Are the alarm bells ringing yet?

This study was published in the journal of Proceedings of the Natural Academy of Science. Which of course, I'd like to read, but I am not made of money, and therefore have to rely on other people's summaries of the study (I'd go broke trying to get my hands on all the studies I want to read). Which brings up a whole different topic - what good is scientific research if access to such publications is restricted to the few individuals who can afford to subscribe to every scientific publication known to man? It's elitist, and it's archaic.

From what I can tell, a similar study was originally published in the journal Science in July of this year by Elizabeth Pennisi. Not entirely sure, as I don't have access to that journal either (although I have asked a friend with access to track it down - so I may update this later).

So what plants are going, going, or gone? Wood Anemones, buttercups, asters, campanulas, bluets (we still have bluets in my yard - they change color based on the mineral composition of the exact spot where they grow - vary in a matter of feet), bladderworts, dogwoods (7 were observed by Thoreau, 5 are now locally extinct or rare), lilies (the Canada Lily is now a goner at Walden), mints, orchids (I wonder if the Globe author was referring in particular to lady slippers which I seem to have a harder time finding now - used to be in my parents yard some 8 miles or so from Walden - no more), roses, saxifrages & violets (particularly the sweet white violet).

Here's what the local television station had to say about this study by Charles C. Davis of Harvard University. Its basically the same information that the globe had, with the added benefit of a quote from Mike Frederick, Executive Director of the Thoreau Society in which he describes how Walden hasn't frozen solid the past two winters (it "usually" does - or perhaps "used to" is more accurate). When I was a kid, there used to be ice fishing on Walden. I don't think thats very popular (or even possible) there anymore.

The frustrating thing about coming across references to scientific publications when I can't get my hands on the article itself is that I have NO idea whether Pennisi or Davis looked into the local deer population explosion, increased carbon dioxide levels at ground level, changes in the forest habitat around Walden Pond due to management techniques or natural forest succession, or increases in foot traffic due to tourists. It seems like there could be many other factors that may affect the proliferation (or lack thereof) of these wildflowers. I'm hoping they've somehow ruled out other factors scientifically & proven that. The skeptic in me is strong, however...