Εμφάνιση αναρτήσεων με ετικέτα climate. Εμφάνιση όλων των αναρτήσεων
Εμφάνιση αναρτήσεων με ετικέτα climate. Εμφάνιση όλων των αναρτήσεων

8/1/11

Budding research links climate change and earlier flowering plants

percent) bloomed earlier from 2005 to 2008 than when he recorded the same species' blooming times from 1992 to 1996. Forty-five percent of the plants bloomed at the same time, and 16 percent bloomed earlier.

"I was doing a plant survey to see how the wetlands had changed over the years, and I noticed a lot of the plants were blooming earlier than they had in the previous survey," said Conover.

The biologist pointed out that the mean annual temperature during the survey periods increased nearly 2 degrees from 53.38 degrees (11.88 C) to 55.27 degrees (12.93 C) in roughly a decade's time.

"This is a big change for such a short time period," said Conover. "There is a lot of data coming from all over the world indicating that biological communities are being impacted by warmer temperatures."

To determine the impact of these changes, Conover said scientists would need to look closely at the complete ecological picture, including the impact on insects and birds that interact with the plants.

"If the right insects aren't out at the right time, it could affect some of the cross-pollination that goes on," he said. Or it could affect certain birds that depend on the seeds from those plants. Everything is interrelated. It is hard to say what impact it will have. We could also see things like more invasive species moving in because of the warmer conditions."

Conover worked closely with UC's Steve Pelikan, a math professor, who crunched all the data from the surveys. Pelikan said he found both the number of earlier-flowering plants and the temperature change from one survey to the next to be statistically significant.

Conover's wild-plant research follows a similar pattern of findings from a recent 30-year garden-plant study in southwestern Ohio (McEwan, et al.). Pelikan points out that Conover's published research is significant because it is one of the first to highlight the earlier flowering phenomena among plants in a natural habitat as opposed to a more-controlled garden setting.

"His is one of the first papers to reach this conclusion when working with native plants in a native setting," said Pelikan.

Further substantiating the work, Conover has found that his observations also aren't unique to the Shaker Trace Wetlands. He's finding similar results as he compares data he collected from a plant survey in 2000 at Oxbow -- a wetland at the confluence of the Great Miami and Ohio Rivers that spans southeastern Indiana and southwestern Ohio -- to data from today.

He's also noticed the presence of new invasive species in the Oxbow area such as Callery pear, Japanese stiltgrass and Japanese chaff flower.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Cincinnati. The original article was written by John Bach.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.


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2/1/11

2-million-year-old 'mummy trees' reveal harsh climate

. He and his colleagues flew back in the summer of 2010 by hopping from city to city, and then switched to a Twin Otter light aircraft before heading to the site in a helicopter.

Getting up there
The researchers were racing against time, because they had a planned field season of just two weeks. But foggy weather kept them grounded in Nunavut, Canada, for a week, which left them with just four days by the time they reached Ellesmere Island National Park.

"We spent our time just running around," Barker told LiveScience. "We pulled long days."

They managed to gather what they considered as representative samples of the mummified tree branches, roots and leaves, as well as larger quantities to examine back in the lab. But they also hope to go back with a broader group of experts and spend at least one month on-site.

Chemical and DNA analyses of the tree mummy samples is ongoing as the researchers try to better understand the conditions at the time. Eventually, they hope to run the story of what happened to the trees in reverse and figure out how the Arctic environment will adapt to the warming world of today.

"I think there's so much work that can be done here, and we want to do that," Barker said.

You can follow LiveScience Senior Writer Jeremy Hsu on Twitter @ScienceHsu.

© 2010 LiveScience.com. All rights reserved.


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