Tag Archives: salt marshes

With Fewer Hard Frosts, Tropical Mangroves Push North

COLLEGE PARK, Md. – Cold-sensitive mangrove forests have expanded dramatically along Florida’s Atlantic Coast as the frequency of killing frosts has declined, according to a new study based on 28 years of satellite data from the University of Maryland and the Smithsonian Environmental Research Center in Edgewater, Md.

Between 1984 and 2011, the Florida Atlantic coast from the Miami area northward gained more than 3,000 acres (1,240 hectares) of mangroves. All the increase occurred north of Palm Beach County. Between Cape Canaveral National Seashore and Saint Augustine, mangroves doubled in area. Meanwhile between the study’s first five years and its last five years, nearby Daytona Beach recorded 1.4 fewer days per year when temperatures fell below 28.4 degrees Fahrenheit (-4 degrees Celsius). The number of killing frosts in southern Florida was unchanged. (more…)

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Confirmed: Stress Gradient Hypothesis: How Plant Communities Endure Stress

The Stress Gradient Hypothesis holds that as stress increases in an ecosystem, mutually supportive interactions become more significant and negative interactions, such as competition, become less so. The idea has been hotly debated but is now backed by a review of hundreds of studies co-authored in Ecology Letters by Mark Bertness, professor of biology at Brown, who first formally proposed the hypothesis in 1994. The time has come, he said, to test its application and predictive value.

PROVIDENCE, R.I. [Brown University] — Ecology is rife with predation, competition, and other dramatic “negative interactions,” but those alone do not determine the course life on Earth. Organisms sometimes benefit each other, too, and according to the Stress Gradient Hypothesis, their “positive interactions” become measurably more influential when ecosystems become threatened by conditions such as drought. Ecologists have argued about the hypothesis ever since Brown University ecologist Mark Bertness co-proposed it in 1994; Bertness says a large new global meta-analysis he co-authored in Ecology Letters definitively shows that it is true. (more…)

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Student’s Curiosity Produces Ecological Buzz

Students studying what they love is a well-established principle at Brown. For Tyler Coverdale, that meant the outdoors, the environment, and, ultimately, some provocative research on Cape Cod salt marshes through GIS-assisted analysis of historical aerial photography. He loves it.

Tyler Coverdale’s newly published study in Frontiers in Ecology and the Environment on the collapse of salt marsh habitats along Cape Cod tells an intriguing, if unfortunate, tale of how three different human activities spanning 70 years finally added up to a problem that no one anticipated. The story of how he made the discovery — which is generating some buzz in ecology — while a Brown undergraduate is a tale of happier serendipities. (more…)

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Heather Leslie: Measuring ocean health

Sustainable management of a huge, complex and valuable resource such as the ocean requires a comprehensive metric that did not exist until now. In the Aug. 16 edition of Nature a broad group of scientists including Heather Leslie, the Sharpe Assistant Professor of Environmental Studies, describes the Ocean Health Index. The index rates coastal places, from regions to nations, on 10 goals: artisanal fishing opportunity, biodiversity, carbon storage, clean waters, coastal livelihoods and economies, coastal protection, food provision, natural products, sense of place, and tourism and recreation. Leslie recently answered questions posed by David Orenstein.

How does the Ocean Health Index’s focus on integrating human factors make it different and valuable?

Recognizing people’s integral roles in ocean ecosystems, this index evaluates how well the ocean provides 10 key benefits to people and how well we are protecting its ability to do so in the future. (more…)

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