In a high-performance machine, each part is essential to the overall function of the whole. In ecology, species diversity is necessary to the smooth operation of the ecosystem. Until recently, little attention has been paid to the potential ecological effects on plant diversity from combined global environmental changes including increased atmospheric CO2, warming, elevated nitrogen pollution, and increased precipitation. Scientists from the Carnegie Institutions Department of Global Ecology in Palo Alto, California, and Stanford University published a study on this subject in the June 16-20, 2003, Proceedings of the National Academy of Sciences Online Early Edition. "We were surprised at how quickly some environmental changes can alter the complexion of an ecosystem," said Erika Zavaleta, the studys lead author and a new member of the faculty at the University of California, Santa Cruz. The finding is significant for understanding what can happen to ecosystems when confronted with the interrelated climactic and atmospheric changes that are observed today and that presage larger changes in the future.
The Carnegie and Stanford scientists conducted their three-year study in the Jasper Ridge Biological Preserve - a typical California grassland where the 43 plant species are a mixture of grasses and wildflowers. "We simulated a series of possible future environments for California, with four global change factors: elevated CO2, warming, nitrogen pollution, and added precipitation, alone and in combinations. Different combinations with altered levels of two, three, and four of these variables are likely to reflect future conditions in different parts of the globe," said Chris Field, director of the Carnegie Institutions Department of Global Ecology and coordinator of the Jasper Ridge study.
"At the end of three years, we found that treatments with three of the four experimental treatments changed total plant diversity. Elevated CO2 reduced diversity as did adding nitrogen. More water increased plant diversity and, warming alone had no effect," Zavaleta explained. The four treatment combinations that represent likely possible futures all resulted in decreased wildflower diversity; but total diversity was not affected because there was an increase in the grasses. The largest loss of wildflower diversity came with elevated CO2 plus warming and nitrogen pollution, and all four of the factors combined. "Given the importance of the wildflower species for wildlife, nutrient cycling, and natural beauty, the losses under realistic global changes are a cause for concern," said Zavaleta.
Chris Field | EurekAlert!
Dead trees are alive with fungi
10.01.2018 | Helmholtz Centre for Environmental Research (UFZ)
Management of mountain meadows influences resilience to climate extremes
10.01.2018 | Max-Planck-Institut für Biogeochemie
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...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
16.01.2018 | Materials Sciences
16.01.2018 | Materials Sciences
16.01.2018 | Power and Electrical Engineering