Climate change may aid invasive wetland plants
According to a Duke University study conducted at 24 river-fed wetland sites in the Southeast, changes linked to global warming may give invasive wetland plants a slight but significant competitive edge over less adaptable native species.
“Changing surface-water temperatures, rainfall patterns and river flows will likely give Japanese knotweed, hydrilla, honeysuckle, privet and other noxious invasive species an edge over less adaptable native species,” said Neal Flanagan, visiting assistant professor at the Duke Wetland Center, who led the three-year research project.
Increased human disturbances to watersheds and nutrient and sediment runoff into those wetlands over the coming century will further boost the invasive species’ advantage, the study found. If left unchecked, the authors said, over time these changes will reduce the diversity of plants found in many wetlands and could affect their ability to mitigate flooding, store carbon, filter out water pollution and provide habitats for native wildlife.
The findings were published last week in the journal Ecological Applications. duke.edu
Surprising new diet tool: simple potato extract
A simple potato extract may limit weight gain from a diet that is high in fat and refined carbohydrates, according to scientists at Montreal’s McGill University.
One group of lab mice was fed an obesity-inducing diet for 10 weeks. The results soon appeared on the scale: Mice that started out weighing on average 25 grams gained about 16 grams. But mice that consumed the same diet – but with a potato extract – gained only 7 grams. The benefits of the extract come from its high concentration of polyphenols, a chemical component found in fruits and vegetables.
Popularly known for its carbohydrate content, the potato is also a good source of polyphenols. “In the famous French diet, considered to be very healthy, potatoes – not red wine – are the primary source of polyphenols,” said Stan Kubow, principal author of the study. “In North America, potatoes come third as a source of polyphenols – before the popular blueberries.” mcgill.ca
Here’s why Dec. 21 is the year’s shortest day
When does winter officially start? At 6:03 p.m. Dec. 21, the sun will be at its most southern point in the sky this year. The Pisgah Astronomical Research Institute, southwest of Asheville explained the science behind it:
“At this moment the sun – in its apparent path around the sky – will stand directly over the Tropic of Capricorn. For an observer at that latitude, the sun will appear directly overhead at noon.” But in North Carolina, “the noontime sun will appear only about 31 1/2 degrees above the southern horizon, its lowest point of the year. What’s more, the sun rises at its most southern point along the southeastern horizon and sets at its most southern point on the southwestern horizon.”
The result? The shortest day and longest night of the year. “For example, in Brevard sunrise occurs at 7:36 a.m. and sunset at 5:23 p.m.,” according to PARI. “Thus, it is above the horizon only 9 hours 47 minutes.”
Then the days will begin to lengthen. Staff reports