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jueves, 25 de febrero de 2016

NSF: Ecologists test stability of Maine ecosystem over two decades .- Los ecologistas ponen a prueba la estabilidad del ecosistema marino de más de dos décadas.....



Ecologists test stability of Maine ecosystem over two decades

Unprecedented field studies of alternative stable states play out in the rocky intertidal zones of Swan’s Island, Maine
Working on a lobster boat in Swan's Island, Maine, typically means an early wake-up call. The boats head out around 5:30 in the morning.
For University of Pennsylvania ecologist Peter Petraitis, California State Northridge biologist Steve Dudgeon and their team, it's not much later when they head out as well. But they're used to it. Petraitis and Dudgeon, along with Cheverus High School teacher Erika Rhile and her students, have been returning to this rocky intertidal zone every spring and summer for nearly two decades!
With support from the National Science Foundation (NSF), they survey a network of 60 experimental plots all around the island. The big question that brings them back year after year: Is an ecosystem like this a stable and permanent fixture, or, under harsh conditions, could it reach a tipping point? The idea is that changes in conditions could cause a switch from one community to another, such as from mussel beds to rockweed, and then back again.
In the Gulf of Maine, winter ice scour often removes mussels and rockweed, but it is not known if the species re-establishment is accidental (that is, ice scour can switch a rockweed stand into a mussel bed and vice versa) or deterministic (mussel beds always return to mussel beds). In ecology, the idea that disturbances such as fires, hurricanes, and even oil spills can abruptly switch one community type into another is known as the theory of alternative stable states.
Ecologists have watched such switches all over the country and sometimes, switches have undesirable consequences, such as when human activities impact coral reef communities or the loss of productive edible grasslands in the Southwest. The experimental approach of Petraitis and his colleagues has never been used to test for alternative states under natural conditions and the research has broad implications for studies of alternative states in other ecological communities.
The research in this episode was supported by NSF award #1020480, LTREB: Experimental tests of alternative states on rocky intertidal shores. LTERB stands for Long Term Research in Environmental Biology.
A team of researchers from Northeastern University and Oregon State University has published results of an investigation of the effects of climate change on coastal ocean upwelling, the process by which deep, cold waters rise toward the surface, bringing nutrients. The results indicate that by the end of the 21st century, periods of annual upwelling in particular coastal areas will lengthen and intensify, while the differences in upwelling across latitudes will diminish. Find out more in this news release.
Credit: Tarik C. Gouhier, Marine Science Center, Northeastern University
Salt marshes in Hatches Harbor, Mass.
When restoring coastal wetlands, common practice calls for leaving space between new plants to prevent overcrowding and reduce competition for nutrients and sunlight. That’s likely all wrong. A November 2015 study, conducted to restore degraded salt marshes in Florida and the Netherlands, has found that clumping newly planted marsh grasses next to each other, with little or no space in between, can spur positive interactions between the plants. Find out more in this discovery.
Credit: USGS
Related Links
The Division of Environmental Biology (DEB) of the Biological Sciences Directorate supports fundamental research on populations, species, communities and ecosystems. Scientific emphases range across many evolutionary and ecological patterns and processes at all spatial and temporal scales.
In August 2014, six jurisdictions received Research Infrastructure Improvement (RII) Track-1 awards from NSF’s Experimental Program to Stimulate Competitive Research (EPSCoR). Each award targets technologically relevant strategic themes. The research, education and outreach activities also consider economic and environmental factors related to the consequences of climate disruption. Two of the jurisdictions (Maine and the U.S. Virgin Islands) are focusing on coastal ecological challenges.
The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
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