Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Trees and shrubs invading critical grasslands, diminish cattle production

19.08.2014

Researchers discover rapid change in ecosystem services

Half of the Earth's land mass is made up of rangelands, which include grasslands and savannas, yet they are being transformed at an alarming rate. Woody plants, such as trees and shrubs, are moving in and taking over, leading to a loss of critical habitat and causing a drastic change in the ability of ecosystems to produce food — specifically meat.


Grasslands are being transformed at an alarming rate as woody plants, such as trees and shrubs, take over. This is leading to a loss of critical habitat and causing a drastic change in the ability of ecosystems to produce food. This is one example near the Santa Rita mountains in Arizona.

Credit: Osvaldo Sala

Researchers with Arizona State University's School of Life Sciences led an investigation that quantified this loss in both the United States and Argentina. The study's results are published in today's online issue of the scientific journal Proceedings of the National Academy of Sciences (PNAS).

"While the phenomenon of woody plant invasion has been occurring for decades, for the first time, we have quantified the losses in ecosystem services," said Osvaldo Sala, Julie A. Wrigley Chair and Foundation Professor with ASU's School of Life Sciences and School of Sustainability. "We found that an increase in tree and shrub cover of one percent leads to a two percent loss in livestock production." And, woody-plant cover in North America increases at a rate between 0.5 and two percent per year.

In recent years, the U.S. government shelled out millions of dollars in an effort to stop the advance of trees and shrubs. The U.S. Natural Resources Conservation Service spent $127 million from 2005-2009 on herbicides and brush management, without a clear understanding of its economic benefit.

The research team used census data from the U.S. and Argentina to find out how much livestock exists within the majority of the countries' rangelands. In both countries, the team studied swaths of rangeland roughly the size of Texas — approximately 160 million acres each. These lands support roughly 40 million heads of cattle. Researchers also used remote sensors to calculate the production of grasses and shrubs. And, to account for the effects of different socioeconomic factors, researchers quantified the impact of tree cover on livestock production in two areas of the world that have similar environments, but different level of economic development.

Surprisingly, the presence of trees explained a larger fraction of livestock production in Argentina than in the US.

"What's happening in Argentina seems to be a much narrower utilization of rangelands," added Sala. "The land there is mostly privately-owned and people who have ranches are producing predominantly meat to make a profit. But in the U.S., many people who own ranches don't actually raise cattle. They are using the land for many other different purposes."

While ranchers clearly depend on grasslands to support healthy livestock, ecosystems also provide a range of other services to humans. Stakeholders such as conservationists, farmers, builders, government entities and private landowners, depend on the land for a variety of reasons and each has different values and land use needs.

Why are trees and shrubs taking over grasslands? There are several hypotheses as to why woody plant encroachment is happening. Fire reduction, grazing intensity, climate change, and increased carbon dioxide in the atmosphere are some widely held beliefs as to the cause. However, Sala's study is focused not on the cause, but rather on the cost of this change to people.

"For each piece of land, there are different people who have an interest in that land and they all have different values. And, they are all okay," said Sala. "However, in order to negotiate how to use the land and to meet the needs of these different stakeholders, we need concrete information. We now know how much increase in tree cover is affecting the cattle ranchers."

Sala and his colleagues hope that the information found in their study will be used to inform discussions as policy makers and other stakeholders negotiate changes in land use. Researchers who took part in the study include Sala and Billie Turner II with ASU, José Anadón with City University of New York, and Elena Bennett with McGill University. National Academies Keck Futures Initiative and the U.S. National Science Foundation funded the study.

###

ASU's School of Life Sciences is an academic unit of the College of Liberal Arts and Sciences.

Sandra Leander | Eurek Alert!
Further information:
http://www.asu.edu

Further reports about: Arizona Foundation ecosystems grasslands livestock meat rangelands savannas shrubs stakeholders

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

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: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>