Two different studies separated by more than 1,700 miles hammer home the same point: evidence of global warming is everywhere. In Yellowstone National Park, researchers found that amphibian populations have declined dramatically over the past 15 years as some of their pond habitats have dried up and disappeared. Meanwhile, in Massachusetts’ Walden Pond, botanists discovered that more than a quarter of the plant species observed by Henry David Thoreau have disappeared since the author went to the woods to “live deliberately” in the 1850s.
The two studies, which both appear in the Proceedings of the National Academy of Sciences [subscription required], show that changes to the planet’s flora and fauna are already well underway. The Yellowstone study compared data from an amphibian survey done in 1992 and 1993 to data from a new survey conducted over the last three summers; researchers looked at the park’s “kettle” ponds, which are re-filled in spring by groundwater and snow melt running down from the hills [BBC News]. The researchers found that the number of permanently dry ponds had quadrupled, and even in the ponds that remained, amphibian populations had plummeted.
