Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Ancient leaves point to climate change effect on insects

Insects will feast and leafy plants will suffer if temperatures warm and atmospheric carbon dioxide increases, according to a team of researchers who studied evidence of insect feeding on fossil leaves from before, during and after the Paleocene-Eocene Thermal Maximum.

The PETM occurred 55.8 million years ago and was an abrupt global warming event linked to a temporary increase in carbon dioxide in the atmosphere. This event is comparable in size and rate to the current climate changes brought on by human activity.

"Our study suggests that increased insect herbivory is likely to be a net, long-term effect of anthropogenic carbon dioxide increase and warming temperature," the researchers report today (Feb.11) in the online Proceedings of the National Academy of Sciences.

Today, the tropics have the most diverse insect populations and the highest rate of herbivore damage on leaves. This implies that there is a correlation between insect feeding and temperature. The researchers, who include Ellen D. Currano, graduate student in geoscience, and Peter Wilf, associate professor of geoscience, Penn State; Scott L. Wing and Conrad C. Labandeira, Department of Paleobiology, Smithsonian Institution; Elizabeth C. Lovelock, graduate student in earth science, University of California, Santa Barbara; and Dana L. Royer, assistant professor, earth and environmental sciences, Wesleyan University, looked at fossil leaves from the Bighorn Basin in north central Wyoming from layers deposited in the late Paleocene, in the middle of the PETM and in the early Eocene.

"We looked at these time periods to see evidence of insect feeding and to count the types of damage," says Currano. "We looked to see how much damage the insects did and the kinds of leaves on which the damage occurred."

They identified 50 types of damage on the fossil leaves including holes of varying sizes, chewed-out areas, galls and mines.

"We can identify certain insect groups by the way they feed on a leaf," says Currano. "Some make mines while others chew along the edge of the leaf."

By looking at modern insect's behavior, the researchers can determine the types of insects eating the fossil leaves. They compare modern leaf damage to that occurring in the past.

The team found that the percent of leaves damaged by insects was 15 to 38 percent during the Paleocene and 33 percent during the Eocene, but increased to 57 percent during the intermediate PETM. This large increase in insect herbivory corresponded to a time of increased carbon dioxide and temperatures. The researchers also found that the increased feeding occurred in all plant species and that a more diverse array of insects fed on the leaves.

The researchers investigated the leaves that grew during the PETM to ensure that the leaves growing then were not tougher and less tasty than those found before or after that period. They found no differences between the heavily eaten leaves and those from time periods with less herbivory.

"With more carbon dioxide available to plants, photosynthesis is easier and plants can make the same amount of food for themselves without having to put so much protein in their leaves," says Currano.

Consequently, when carbon dioxide increases, leaves have less protein and insects need to eat more to acquire the nutrients they need. While increased carbon dioxide is good for the plants in that they can increase growth, plants also suffer from increased feeding by insects.

The researchers explain that the increase in insect feeding is a result of the tripling of carbon dioxide in the atmosphere during the PETM and the accompanying rise in temperature. They think that increases in temperature and carbon dioxide levels during the PETM are good analogs for the future and therefore, that plants may eventually experience higher rates of feeding as humans put more carbon dioxide into the atmosphere.

Andrea Elyse Messer | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>