Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.
"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease these conversions," said Constance Millar, lead author and forest ecologist with the USDA Forest Service's Pacific Southwest Research Station.
Many forests are remarkably resilient, re-growing after years of logging. Yet, the researchers note from review of the enormous body of work on the subject, climate change and rising global temperatures are giving rise to "hotter" droughts -- droughts that exhibit a level of severity beyond that witnessed in the past century.
During a hotter drought, high air temperatures overheat leaves and also increase the stress on trees by drawing the moisture from their tissues at faster rates than normal. Snow that would normally act as emergency water storage for trees during the dry season instead falls as rain.
Combined, these factors may cause abnormally high levels of forest mortality during hotter droughts.
"Some temperate forests already appear to be showing chronic effects of warming temperatures, such as slow increases in tree deaths," said Nathan Stephenson, coauthor and ecologist with the U.S. Geological Survey. "But the emergence of megadisturbances, forest diebacks beyond the range of what we've normally seen over the last century, could be a game-changer for how we plan for the future."
Chronic stress from drought and warming temperatures also expose temperate forests to insect and disease outbreaks. And as temperatures rise in many regions, fires grow in frequency and severity causing losses in private property, natural resources and lives.
Losing temperate forests to worsening droughts, megafires and insect and disease outbreaks could lead to widespread losses of forest ecosystem services like national park recreational areas, the researchers caution. Forests also play an important role in storing atmospheric carbon dioxide and watershed protection, for example.
The scientists encourage future studies identifying forests most vulnerable to the effects of mega-disturbances. In some cases, forest managers may be able to preserve ecosystem services like carbon storage as temperate forests transition to new ecological states.
The paper, "Temperate Forest Health in an Era of Emerging Megadisturbance," was released in the journal Science.
To read the paper, view or download the publication from Treesearch, the U.S. Forest Service online system for sharing free, full text publications by Research and Development scientists.
Headquartered in Albany, Calif., the Pacific Southwest Research Station develops and communicates science needed to sustain forest ecosystems and other benefits to society. It has research facilities in California, Hawaii and the U.S.-affiliated Pacific Islands. For more information, visit fs.fed.us/psw/.
Pacific Southwest Research Station/USDA Forest Service
Science that makes a difference
Carlos Milán | EurekAlert!
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology