Featured Research

from universities, journals, and other organizations

Wildflower Declines In Thoreau's Concord Woods Are Due To Climate Changes

Date:
November 1, 2008
Source:
Harvard University
Summary:
Drawing on records dating back to the journals of Henry David Thoreau, scientists have found that different plant families near Walden Pond have borne the effects of climate change in strikingly different ways. Some of the plant families hit hardest by global warming have included beloved species like lilies, orchids, violets, roses, and dogwoods.

Dogwood flowers. Plant families that have been especially hard-hit by global warming have included lilies, orchids, buttercups, violets, roses, dogwoods, and mints.
Credit: iStockphoto/Melissa Carroll

Drawing on records dating back to the journals of Henry David Thoreau, scientists at Harvard University have found that different plant families near Walden Pond have borne the effects of climate change in strikingly different ways. Some of the plant families hit hardest by global warming have included beloved species like lilies, orchids, violets, roses, and dogwoods.

Related Articles


Over the past 150 years, some of the plants in Thoreau's woods have shifted their flowering time by as much as three weeks as spring temperatures have risen, the researchers say, while others have been less flexible. Many plant families that have proven unable to adjust their flowering time have experienced sharp declines or even elimination from the local landscape -- the fate of nearly two-thirds of the plants Thoreau found in the 1850s around Walden Pond in Concord, Mass.

"It had been thought that climate change would result in uniform shifts across plant species, but our work shows that plant species do not respond to climate change uniformly or randomly," says Charles C. Davis, assistant professor of organismic and evolutionary biology in Harvard's Faculty of Arts and Sciences. "Some plants around Walden Pond have been quite resilient in the face of climate change, while others have fared far worse. Closely related species that are not able to adjust their flowering times in the face of rising temperatures are decreasing in abundance."

Some 27 percent of all species Thoreau recorded in the mid-19th century are now locally extinct, and another 36 percent are so sparse that extinction may be imminent. Plant families that have been especially hard-hit by global warming have included lilies, orchids, buttercups, violets, roses, dogwoods, and mints. Many of the gainers have been weedier mustards and knotweeds, along with various non-native species.

"The species harmed by climate change are among the most charismatic found in the New England landscape," Davis says. Scientists can be reasonably confident these losses have resulted from climate change and not habitat loss, he adds, since 60 percent of the land in Concord has remained protected or undeveloped since Thoreau's observations of the area between 1851 and 1858.

Understanding the decline of species abundance over time is constrained by the limited availability of historic data. Davis' work with Harvard graduate students Charles Willis and Brad Ruhfel combines contemporary data, collected by scientists Richard Primack and Abraham Miller-Rushing at Boston University, with Thoreau's records from his time spent at Walden Pond. Thoreau kept meticulous notes documenting the natural history of the region, plant species occurrences, and flowering times. Since then, botanists have resurveyed the territory to create a unique, community-level perspective covering 150 years. During this period, the mean annual temperature in the Concord area has increased by 2.4 degrees Celsius, or 4.3 degrees Fahrenheit.

"The plants in our survey now flower, on average, one week earlier in the spring than their ancestors did in Thoreau's time," Davis says. "However, there is wide variation among plant families. Some have shown no shift in flowering at all, while others now bloom 16 to 20 days earlier in the spring."

As mean annual temperatures increase, plants can adjust their growth patterns in several ways. For example, forests shift toward the poles, alpine tree lines move up mountains to higher altitudes, and flowering time can shift. During eras of climate change, plants that cannot adjust their flowering schedule -- and thus flower at sub-optimal times -- may experience dramatic declines in population size and local extinction.

The work appears this week in the Proceedings of the National Academy of Sciences.

Davis' co-authors are Harvard graduate students Charles Willis and Brad Ruhfel and Richard Primack and Abraham Miller-Rushing of Boston University. Their work was supported by the National Science Foundation.


Story Source:

The above story is based on materials provided by Harvard University. Note: Materials may be edited for content and length.


Cite This Page:

Harvard University. "Wildflower Declines In Thoreau's Concord Woods Are Due To Climate Changes." ScienceDaily. ScienceDaily, 1 November 2008. <www.sciencedaily.com/releases/2008/10/081027174640.htm>.
Harvard University. (2008, November 1). Wildflower Declines In Thoreau's Concord Woods Are Due To Climate Changes. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2008/10/081027174640.htm
Harvard University. "Wildflower Declines In Thoreau's Concord Woods Are Due To Climate Changes." ScienceDaily. www.sciencedaily.com/releases/2008/10/081027174640.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Cambodian Capital's Only Working Elephant to Retire in Jungle

Cambodian Capital's Only Working Elephant to Retire in Jungle

AFP (Nov. 25, 2014) Phnom Penh's only working elephant was blessed by a crowd of chanting Buddhist monks Tuesday as she prepared for a life of comfortable jungle retirement after three decades of giving rides to tourists. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins