Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Long-term Study Shows Effect of Climate Change on Animal Diversity

24.09.2008
Two species of giraffe, several rhinos and five elephant relatives, along with multitudes of rodents, bush pigs, horses, antelope and apes, once inhabited what is now northern Pakistan.

But when climate shifted dramatically there some 8 million years ago, precipitating a major change in vegetation, most species became locally extinct rather than adapting to the new ecosystem, according to an extensive, long-term study of mammal fossils spanning a 5-million-year period.

Results of the study, by University of Michigan paleoecologist Catherine Badgley and coworkers, are scheduled to be published online in the Proceedings of the National Academy of Sciences the week of Aug. 18.

The work has value not only in reconstructing Earth's past, but also for understanding what may lie ahead if current climate trends continue, Badgley said. "Climate is going to produce changes in ecological structure of all sorts of plants and animals around the world, now as in the past. The fossil record can help us understand how much---or how little---climate change is necessary to produce changes in ecosystems."

Badgley is part of an interdisciplinary team of geologists and paleontologists that has been studying the fossil-rich Siwalik sedimentary rocks in northern Pakistan for more than 30 years. The Siwalik Group of sediments contains one of the world's most complete and best-studied fossil records of mammals, chronicling in a two-mile-thick deposit of rock the mammals that roamed the area from 18 to 1 million years ago. About 8 million years ago, the local climate became drier, and the prevailing vegetation changed from tropical forests and woodland to a savannah similar to that found in parts of Africa today.

What happened next can be reconstructed from the chemistry and wear of the teeth of the plant-eating mammals, as well as the longevity of each species during the period when vegetation was changing. The teeth provide evidence of the animals' diets, revealing whether they switched to eating the newly abundant grasses when their favored fruits and broad-leafed plants were no longer available.

Mammals that relied on fruit and browse disappeared early in the transition from forest to savannah vegetation and were not replaced, while those that ate broad leaves and grasses either adapted and persisted by changing their diets to include more grass or disappeared and were replaced by immigrant species with similar diets. By the time that savannah was the dominant vegetation, most herbivorous mammals in the area subsisted mainly on grass. The overall effect was a significant decline in the diversity of mammals in the area.

"We see quite a different ecological profile of the kinds of mammals that coexisted after this climate change than before," said Badgley, who is an assistant professor of ecology and evolutionary biology, as well as a research scientist in the Department of Geological Sciences and the Museum of Paleontology. "It's clear that climate has had an impact on the ecological diversity of mammals in the area."

In addition to providing compelling evidence for the effects of climate change on ecological systems, the paper is a testament to the value of long-term research in a single field area, Badgley said. "This is the kind of study you can only do after you've been working in a place with a big team for 25 years or more, because you need all the other basic data to be thoroughly resolved before you can even start to address the kinds of questions in this work. We've been fortunate to have a team that found the various research topics so worthwhile and so interesting that they stuck with it for several decades, and we've also been fortunate to receive funding for field work for that long."

Badgley's co-authors on the PNAS paper are John Barry, Michèle Morgan and David Pilbeam of Harvard University; Sherry Nelson of the University of New Mexico; Kay Behrensmeyer of the National Museum of Natural History and Thure Cerling of the University of Utah. The research described in the paper was supported by a grant from the National Science Foundation.

Nancy Ross-Flanigan | Newswise Science News
Further information:
http://www.umich.edu
http://www.pnas.org/
http://www.ns.umich.edu/htdocs/public/experts/ExpDisplay.php?ExpID=1337

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>