Research spanning 6 continents sheds light on important interactions among nutrients, grazers, and plants
Two wrongs may not make a right. But when it comes to grassland plant species diversity, it just might. Two impacts often controlled by humans — being fertilized and being eaten — can combine to the benefit of biodiversity, according to an innovative international study led by U of M researchers Elizabeth Borer and Eric Seabloom.
The findings, published March 9 in the online edition of Nature in advance of print publication, are important in a world where humans are changing both herbivore distribution and the supply of nutrients like nitrogen or phosphorus, and where understanding the interplay among nutrients, herbivores and plant growth is critical to our capacity to feed a growing human population and protect threatened species and ecosystems.
To conduct the study, Borer and Seabloom enlisted the help of the Nutrient Network, or NutNet, a collaborative international experiment they and a few colleagues founded in 2005 as a resource for understanding how grasslands around the world will respond to a changing environment. NutNet scientists at 40 sites on six continents set up research plots with and without added fertilizer and with and without fences to keep out the local herbivores such as deer, kangaroos, sheep or zebras. Every year since then, they have measured the amount of plant material grown, light reaching the ground, and number of species of plants growing in the plots.
When the researchers compared data across the 40 study sites, they found that fertilizing reduced the number of plant species in the plots as species less able to tolerate a lack of light were literally overshadowed by fast-growing neighbors. On both fertilized and unfertilized plots, where removal of vegetation by herbivores increased the amount of light that struck the ground, plant species diversity increased. And these results held true whether the grassland was in Minnesota, Argentina or China, and whether the herbivores involved were rabbits, sheep, elephants or something else.
"Biodiversity benefits humans and the environments that sustain us. Understanding how human actions control biodiversity is important for maintaining a healthy environment," says Borer. "What this suggests is that these two impacts, which are ubiquitous globally, dovetail with changes in light availability at the ground level, and that appears to be a big factor in maintaining or losing biodiversity in grasslands. In short, where we see a change in light, we see a change in diversity."
The findings add a key piece to the puzzle of how human impacts affect prairies, savannas, alpine meadows and other grasslands. Biodiversity plays an important role in how resilient communities of plants and animals are in the face of change. By showing how fertilization, grazing, and biodiversity are linked, the research moves us one step closer to understanding what we can do to help keep grassland ecosystems and all of the services they provide healthy and thriving in a changing world.
"Global patterns of biodiversity have largely defied explanation due to many interacting, local driving forces," says Henry Gholz, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the coordination of this research. "These results show that grassland biodiversity is likely largely determined by the offsetting influences of nutrition and grazing on light capture by plants."
Yann Hautier, a Marie Curie Fellow associated with both the Department of Ecology, Evolution, and Behavior at the University of Minnesota and the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich and U of M research scientist Eric Lind were co-authors of the study along with researchers from universities and government agencies around the world.
Stephanie Xenos | EurekAlert!
Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli
26.04.2017 | University of the Basque Country
New data unearths pesticide peril in beehives
21.04.2017 | Cornell University
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...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Materials Sciences
26.04.2017 | Agricultural and Forestry Science
26.04.2017 | Physics and Astronomy