Monday, January 21, 2013

Leopold Plants Bloom Earlier

There is an interesting research study published in which could well have listed Aldo Leopold as a co-author.  The fact that plants are flowering earlier than in the past has been documented by many different studies, but this paper shows that the conclusions for experimental data from controlled studies were too conservative in predicting flowering times.

Phenology is the study of the effect of climate, including seasonal and annual variations, as well as  elevation on plant and animal life.  This has become all the more important as we face the dramatic climate change of the last decade.  The researchers studied bloom times in the same areas as classic studies that were carried out years ago.
To quote:

"From 1852–1858, Henry David Thoreau, author of Walden, observed flowering times in Concord, Massachusetts, USA. And from 1935–1945, Aldo Leopold, author of A Sand County Almanac, recorded flowering times in Dane County, Wisconsin."
"Several recent re-surveys at these locations, nearly 1500 km apart, indicate that many spring-flowering plants now flower much earlier than in the past. This trend appears to be attributable to especially warmer spring (March, April, May) temperatures. In 2010 and 2012 in Massachusetts, and 2012 in Wisconsin, spring temperatures were the warmest on record."
By comparing these careful daily observations of bloom times from 65 and 156 years ago, the authors have been able to document real long term changes in bloom times.  For example, studies on the same parcel of land shows high bush blueberries blooming 6 weeks earlier than they did in the 1850s.

A study done on Leopold's land recently showed a changes in bloom time.  While Leopold recorded the flowering of serviceberry (Amelanchier arborea),  between 10 April and 9 May, this study found it flowering on 25 March, 2012.  Barb's diary shows it blooming in Bull Creek valley 16 March, 2012, ten days after the Bradford pear along the roads.
"These long-term datasets thus provide a rare opportunity to investigate if historical relationships between flowering times and spring temperatures apply during these record-breaking years." 
While their going out daily to record the time that plants first bloomed over a number of years might seem strange or even outright weird to many today (though certainly not Barb) our present day botanists are grateful for their help.

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