Growing food and fiber entails the use of fertilizer and irrigation systems and results in land clearing. These ‘side effects’ of agriculture can lead to regime shifts—or ‘tipping points’ which include desertification, salinisation, water degradation, and changes in climate due to altered water flows from land to atmosphere.
As human populations shift to more meat-heavy diets, trade of agricultural products increases, and demand for biofuels grows, the pressure on agricultural systems is mounting. The challenge is to figure out how to meet these demands and keep the ecosystem functions that underpin productivity working. So say researchers who will participate in a symposium, “Tipping points in the biosphere: Agriculture, water, and resilience” during the Ecological Society of America’s Annual Meeting.
Tipping points occur when an ecosystem is overwhelmed by the demands placed on it and can no longer function the way it did before. In other words, it loses its resiliency which ultimately can lead to land that is rendered useless for growing crops.
Elena Bennett (McGill University), organizer of the symposium, says that we need to better understand large scale regime shifts in order to develop policies that sustain, rather than degrade, the very systems upon which humanity depends.
“One of the reasons agricultural landscapes are so prone to regime shifts is that our management of them has tended to focus exclusively on improving one type of ecosystem service (e.g. food production, fiber production, biofuels production) at the cost of all others,” explains Bennett.
She notes that agriculture is now one of the main driving forces of global environmental change. Bennett and other presenters in this session have identified potential tipping points related to water and agriculture that could have major global consequences.
No human activity has so large an impact on water systems as does agriculture, according to Johan Rockstrom (Stockholm Environment Institute, Sweden). He notes that the future will bring an even greater demand on fresh water for food production—by 2050 global water use for food production alone will need to double.
Line Gordon (Stockholm University, Sweden) will examine the redistribution of vapor flows brought about by irrigation. Gordon notes that the pattern of change varies and identifies the mid-United States, the Amazon, the Sahel, India, and Northern China as the most likely areas to undergo climate change, driven by these altered continental vapor flows.
Ellen Marie Douglas (University of Massachusetts) will focus on potential impacts on India’s Monsoon Belt, home to a large part of the globe’s population. India has the largest irrigated agricultural area in the world, with more than 90 percent of the country’s water supporting irrigated agriculture. Vapor fluxes in India’s wet season are up by 7 percent and are up 55 percent in the dry season. Douglas and her colleagues attribute two-thirds of this change to irrigated agriculture.
Drawing from research examples in the Mississippi River, Simon Donner (Princeton University), will discuss the role of nitrogen fertilizer in the health of downstream ecosystems, in particular their potential sensitivity to climate change.
Navin Ramankutty (McGill University) likens land use changes to fuel emissions in their potential to drive climatic changes. According to Ramankutty, local land cover changes may very likely generate changes elsewhere by altering the general circulation of the atmosphere. He points to Canada, Eastern Europe, the former Soviet Union, Mexico, and Central America as places where land clearing for cultivation may have inadvertently decreased suitability for growing crops.
Brandon Bestelmeyer (USDA-ARS Jornada Experimental Range) will examine tipping points in rangelands and will explore various socio-economic factors contributing to rangeland degradation.
Others presenting at the session are Garry Peterson (McGill University), Lance Gunderson (Emory University), and Max Rietkerk (Utrecht University, The Netherlands).
“Our hope is that if we can identify potential regime shifts, we can alter our management to avoid them,” says session organizer Bennett.
Nadine Lymn | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy