Tag Archives: sea grass beds

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…)

Read More

First Harmful Algal Bloom Species Genome Sequenced

*Brown Tide Culprit Uniquely Suited to Thrive in Environmentally Impacted Estuaries*

The microscopic phytoplankton Aureococcus anophagefferens, which causes devastating brown tides, may be tiny but it’s a fierce competitor.

In the first genome sequencing of a harmful algal bloom species, researchers found that Aureococcus’ unique gene complement allows it to outcompete other marine phytoplankton and thrive in human-modified ecosystems, which could help explain the global increases in harmful algal blooms (HABs). (more…)

Read More