(Press-News.org) DURHAM, N.C. -- In the battle between native and invasive wetland plants, a new Duke University study finds climate change may tip the scales in favor of the invaders -- but it's going to be more a war of attrition than a frontal assault.
"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 E. Flanagan, visiting assistant professor at the Duke Wetland Center, who led the research.
Increased human disturbances to watersheds and nutrient and sediment runoff into riparian wetlands over the coming century will further boost the invasive species' advantage, the study found.
"It's death by a thousand small cuts. Each change, on its own, may yield only a slight advantage for invasive species, but cumulatively they add up," said co-author Curtis J. Richardson, director of the Duke Wetland Center and professor of resource ecology at Duke's Nicholas School of the Environment.
If left unchecked, over time these change will reduce the diversity of plants found in many wetlands and could affect the wetlands' ability to mitigate flooding, store carbon, filter out water pollution and provide habitat for native wildlife, the authors said.
The scientists published their peer-reviewed findings this week in the journal Ecological Applications.
The study, funded by the U.S. Environmental Protection Agency (EPA), is the first large-scale field experiment to simulate how future environmental changes linked to global warming and land-use change will affect plant communities in major river systems in the U.S. Southeast.
It was conducted using plant species and biomass surveys, continuous real-time measurements of water levels and water temperatures, and statistical modeling of long-term plant abundance and growing conditions at 24 riparian floodplain sites in North Carolina and Virginia over a three-year period.
The Intergovernmental Panel on Climate Change (IPCC) projects that surface-water temperatures in the Southeast will increase by 1 to 5 degrees Celsius by the year 2100. Increased evaporation will reduce surface water base flows, while a 5 percent to 30 percent increase in precipitation, mostly in the form of intense storms, will cause pulsed hydrology -- sudden, short-term rises -- in water levels.
As these changes occur, the annual timing of when wetland soils warm up in spring will fluctuate and may no longer be synchronized with when river levels drop, Flanagan said.
This de-synchronization will affect all floodplain plants, but the natural phenotypic plasticity of invasive species allows them to adapt to it better than native species, which need both exposed soil and warmer temperatures to germinate.
As native species' germination rates decline, invasives will move in and fill the void, their increased abundance fueled by high levels of nutrients flowing into the wetlands in runoff from upstream agriculture and other disturbances.
"These findings underscore the need for us to better understand the interaction between climate, land use and nutrient management in maintaining the viability of native riparian plant communities," Richardson said.
"What makes this study so novel is that we used a network of natural, existing riparian wetlands to simulate the long-term impacts of IPCC-projected changes to water temperature and flow over the coming century," Richardson added.
Eighteen of the 24 wetlands used in the study were located downriver from dams or power plants built at least 50 years ago, he said. Ten of these wetlands were classified as warm sites, because water discharged back into the river by the upstream dam or power plant was heated by steam turbines or pulled from higher in a reservoir, where water temperatures were warmer.
Eight wetlands were classified as cold sites because the upstream dams pulled their outflow water from deeper in reservoirs, where temperatures were more than 5 degrees Celsius cooler than at warm sites.
"This allowed us to simulate the effect of long-term changes in water temperatures on native and invasive species abundance," Richardson said. All 18 dams regulated their outflow of water, allowing the team to simulate the effects of projected lower base flow and increased storm flows. Six wetlands in the study were located on undammed rivers and served as control sites.
INFORMATION:
Mengchi Ho, associate in research at the Duke Wetland Center, also co-authored the study, which was funded by the EPA's Science to Achieve Results (STAR) program (grant #83837010).
CITATION: "Connecting Differential Responses of Native and Invasive Riperian Plants to Climate Change and Environmental Alteration," Neal E. Flanagan, Curtis J. Richardson and Mengchi Ho, Duke University. Ecological Applications, Dec. 8, 2014. . http://dx.doi.org/10.1890/14-0767.1
PULLMAN, Wash. - Imagine standing in a long line at your favorite coffee shop only to receive the wrong order. What would you do?
While some might be angry and tell all their friends about the shop's bad service, researchers say other customers may think "it's all good" - IF they learn that the coffee shop donates a percentage of every purchase to charitable causes that customers value.
Corporate social responsibility maximizes consumer return
Writing in the Journal of Public Policy and Marketing, researchers help firms understand when and why corporate social responsibility ...
SAN FRANCISCO (DECEMBER 9, 2014) -Common variations in four genes related to brain inflammation or cells' response to damage from oxidation may contribute to the problems with memory, learning and other cognitive functions seen in children treated for acute lymphoblastic leukemia (ALL), according to a study led by researchers from Boston Children's Hospital, The Children's Hospital at Montefiore, and Dana-Farber/Boston Children's Cancer and Blood Disorders Center.
The data, presented at the 56th annual meeting of the American Society of Hematology (abstract #856), suggest ...
WASHINGTON, D.C., December 9, 2014 - Researchers from the London Centre for Nanotechnology have made new compact, high-value resistors for nanoscale quantum circuits. The resistors could speed the development of quantum devices for computing and fundamental physics research. The researchers describe the thin-film resistors in an article in the Journal of Applied Physics, from AIP Publishing.
One example of an application that requires high-value resistors is the quantum phase-slip (QPS) circuit. A QPS circuit is made from very narrow wires of superconducting material ...
It may be possible to develop a simple blood test that, by detecting changes in the zinc in our bodies, could help to diagnose breast cancer early.
A team, led by Oxford University scientists, took techniques normally used to analyse trace metal isotopes for studying climate change and planetary formation and applied them to how the human body processes metals.
In a world-first the researchers were able to show that changes in the isotopic composition of zinc, which can be detected in a person's breast tissue, could make it possible to identify a 'biomarker' (a measurable ...
December 9, 2014 - Within a few months after drug withdrawal, patients in recovery from dependence on prescription pain medications may show signs that the body's natural reward systems are normalizing, reports a study in the Journal of Addiction Medicine, the official journal of the American Society of Addiction Medicine. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.
The study by Scott C. Bunce, PhD, of Penn State University College of Medicine, Hershey, and colleagues provides evidence of "physiological re-regulation" ...
Physical aggression in toddlers has been thought to be associated with the frustration caused by language problems, but a recent study by researchers at the University of Montreal shows that this isn't the case. The researchers did find, however, that parental behaviours may influence the development of an association between the two problems during early childhood. Frequent hitting, kicking, and a tendency to bite or push others are examples of physical aggression observed in toddlers.
"Since the 1940s, studies have observed an association between physical aggression ...
Several factors influence how well a severely premature infant (23 weeks gestation) will do after birth and over the long term, according to researchers at Loyola University Medical Center. These findings were published in the latest issue of the American Journal of Perinatology.
Researchers found that males, multiples and premature infants born in a hospital without a neonatal intensive care unit had a significantly higher death rate. Lack of exposure to steroids before birth and lower birth weights also significantly increased the risk for disability. Some studies suggested ...
MANHATTAN, Kansas -- A research project in the Kansas State University College of Veterinary Medicine presents the largest model to date for evaluating the impact and control of a potential outbreak of foot-and-mouth disease in livestock.
Mike Sanderson, professor of epidemiology in the college's diagnostic medicine and pathobiology department, and Sara McReynolds, a former graduate student of Sanderson's, published the results of their research in the December issue of the journal Preventive Veterinary Medicine.
The researchers developed simulation models to assess ...
How do wealth and culture affect the international success of a new product, especially for those nations that have to wait? According to a new study in the Journal of International Marketing, national wealth and cultural characteristics such as individualism play a large part in citizens' enthusiasm and patience for new products.
"Even if they have to wait, consumers in wealthy countries are less hesitant to spend money on new products. Cultural factors such as individualism increase patience for adopting new products because of the high value placed on social uniqueness," ...
Scientists at the University of Southampton have discovered variations in an enzyme belonging to the immune system that leaves individuals susceptible to Ankylosing Spondylitis.
The variation in ERAP1 can be detected by genetic testing which, if available, could lead to people becoming aware of the risk of the condition earlier.
Ankylosing Spondylitis is a chronic inflammatory disease which mainly affects joints in the spine. In severe cases, it can eventually cause complete fusion and rigidity of the spine, called "Bamboo spine". It tends to first develop in teenagers ...
