Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Upper Midwest forests are losing diversity, complexity

18.10.2007
Forests in the nation's Upper Midwest have changed greatly since the time of the early settlers. And more changes may be coming.

That's according to research done by Lisa A. Schulte, assistant professor in Iowa State University's department of Natural Resource Ecology and Management and her team of researchers.

"There's been a shift in the entire ecosystem," said Schulte, whose research has recently been published in the journal Landscape Ecology.

For the study, Schulte, along with Laura Merrick of Iowa State; David Mladenoff of the University of Wisconsin, Madison; and Thomas Crow and David Cleland of the U.S. Forest Service, took forest composition information as described in the Public Land Survey from the mid-1800s and compared it with today's forests.

She found that none of the areas surveyed - from Minnesota to Wisconsin to Michigan - have the same tree species makeup as they did 200 years ago.

"This system was made up of largely conifers with some deciduous trees, and now we have the opposite," she said.

Conifers -- mostly pines and other evergreens -- have gotten more scarce while deciduous trees such as aspen, birch and maple have taken their place. Trees in today's forests also tend to be smaller.

"Our analysis shows a distinct and rapid trajectory of vegetation change toward historically unprecedented and simplified conditions," Schulte's published paper says.

"In addition to overall loss of forestland, current forests are marked by lower species diversity, functional diversity and structural complexity compared with pre-Euro-American forests."

The changes have come from several stresses on the ecosystem including pests, diseases, timber harvest and high populations of white-tailed deer, which feed on young trees, according to Schulte.

The effect of humans may be the most important factor in the shift.

"Human land use of forested regions has intensified worldwide in recent decades, threatening long-term sustainability," the report says.

"Primary effects include conversion of land cover or reversion to an earlier stage of successional development. Both types of change can have cascading effects through ecosystems; however, the long-term effects where forests are allowed to regrow are poorly understood."

What is understood, says Schulte, are the stresses the forest changes are having on wildlife, including birds. Schulte has looked at several species of warblers that have historically inhabited the area. According to her findings, the outlook for them doesn't look good.

"These birds don't have much habitat at present, compared to historical times," she said.

They are also an important and beautiful element of biodiversity, she said. They perform an important function in these forests by eating insects that can become forest pests.

Among natural resource professionals, the forests in the Upper Midwest had been suspected to be changing for some time, according to Schulte, but now there is evidence to support the theories.

"We knew that these kinds of changes had happened," she said. "But this is the first paper to really quantitatively look at it across the entire region. So, anytime you can quantitatively show something, it has a lot more power than simple conjecture."

Lisa Schulte | EurekAlert!
Further information:
http://www.iastate.edu

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>