Because grasslands and forests operate in complex feedback loops with both the atmosphere and soil, understanding how ecosystems respond to global changes in climate and element cycling is critical to predicting the range of global environmental changes--and attendant ecosystem responses--likely to occur. In a new study in the premier open access journal PLoS Biology Jeffrey Dukes, Christopher Field, and colleagues treated grassland plots to every possible combination of current or increased levels of four environmental factors--CO2, temperature, precipitation, and nitrogen influx--to simulate likely regional changes over the next 100 years. The results of their long-term experiment reveal that California grasslands, and ecosystems that respond similarly, are not likely to help buffer the rate of climate change by acting as a carbon "sink"--slowing the rise of CO2 levels by storing more carbon in new growth.
The experiments were part of the Jasper Ridge Global Change Experiment (JRGCE), which started on Stanfords 1,200-acre biological preserve in 1997. Since 1998, this grassland ecosystem has been outfitted with an ecologists version of a microclimate controller (complete with CO2 pumps, heaters, and irrigation tubing) and subjected to experimentally controlled atmospheric, climatic, and nutrient conditions. (This study examines the experiments first five years.) To quantify the grassland response to these treatments, the authors estimated net primary production, or NPP (the amount of carbon left over after cellular respiration) by measuring shoot and root growth in 36 circular plots scattered across roughly two acres. The strongest effects on grassland production came from elevated levels of nitrogen (which typically reaches a fertilization limit). Elevated temperature, rainfall, and, surprisingly, CO2, had minimal impacts. These results suggest that increasing concentrations of atmospheric CO2 are not likely to increase growth of the roots and leaves of plants in this grassland. Why not? One possibility involves phosphorus. High levels of CO2 and nitrogen can reduce phosphorus concentrations or limit its uptake in these plants. Ongoing JRGCE experiments are exploring how this and other factors--such as grazing or shifts in seasonal events--might limit the growth effects of CO2.
Its thought that ocean and terrestrial ecosystems have stored nearly half the carbon emissions produced by humans since the industrial revolution. If it turns out that other natural systems also fail to sequester as much carbon as scientists once thought, atmospheric CO2 concentrations will rise even faster than expected--with serious implications for future climate change.
Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta
Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy