The Kansas State University-led study looked at the drought tolerance of 426 species of grass from around the world. The goal was to better understand how grasslands in different parts of the world may respond to the changes in frequency and severity of drought in the future.
Grasslands have several important ecological functions, according to Joseph Craine, research assistant professor of biology and the study's lead author. Grasslands convert and store carbon dioxide, are a food source for grazing animals like cattle and bison, and help cool the surrounding atmosphere.
"The idea is that if you maintain a diverse grassland, you'll have a large number of drought-tolerant species ready to take over critical functions if there is a change in climate or an extended period of drought, like what we've had this year," Craine said. "Yet, we've never known which grasslands have drought-tolerant species in them."
Craine conducted the study with Kansas State University's Troy Ocheltree, research assistant of biology; Jesse Nippert, assistant professor of biology; Gene Towne, biology research associate and Konza Prairie Biological Station fire chief; and Adam Skibbe, information resource specialist for the Division of Biology, as well as with colleagues from the University of Oregon and the Nature Conservancy in Minneapolis, Minn. It is the largest study conducted to quantify how tolerant grass species are to severe drought.
To collect data the team planted 500 species of grass taken from six continents. A majority of seeds were provided by the United States Department of Agriculture, while 52 species were collected from the Konza Prairie in the Flint Hills of Kansas. Grasses were grown on campus in a walk-in growth chamber with high intensity lighting that simulated sunny weather. After six weeks, researchers stopped watering the grass samples and observed at what point each grass stopped being able to take up water.
"In the end they all succumbed to drought," Craine said. "But that was our goal: to stress them all enough to know at what point they give in. What we saw was that some of grass species were about as tough as lettuce, meaning that after a day or two without water they would start to wilt and curl up. Others, however, were able to go for a week or two without water."
When comparing the drought resistance across the sampled species, the team found that drought-resistant grasses are well distributed across the world. As a result, grasslands are more likely to tolerate the increased periods and intensity of drought that are predicted with climate change in the future, Craine said.
"If we still have grasslands that are diverse, the grasslands are going to continue to function relatively well and not change too much," Craine said. "But when we replace our prairies with ones that just have a few species in it, then it's less likely that grasslands will be able to function normally in the future. That affects the animals and other things that depend on grasslands, making it more likely that the whole ecosystem collapses."
Additionally, researchers developed a drought index for the tested species based on the data. The index details each species' tolerance to drought and can help ecologists understand why grasslands around the world are composed of their species. More than 11,000 species of grass exist on Earth.
The benefits of a diverse grassland are evident when the U.S. faced a drought in the 1980s, said Towne, who also collects plant community data.
"After that drought we saw a booming explosion of tall grasses the following year," Towne said. "So it really backs up what the study found: that drought forces the grasslands to adapt to the weather conditions so they can get through that rough period."
The study, "Global diversity of drought tolerance and grassland climate-change resilience," was recently published online at Nature Climate Change: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1634.html
Joseph Craine | EurekAlert!
Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences