Tag Archives: ecologists

Mutual benefits: Stressed-out trees boost sugary rewards to ant defenders

ANN ARBOR — When water is scarce, Ecuador laurel trees ramp up their investment in a syrupy treat that sends resident ant defenders into overdrive, protecting the trees from defoliation by leaf-munching pests.

The water-stressed tropical forest trees support the production of more honeydew, a sugary excretion imbibed by the Azteca ants that nest in the laurels’ stem cavities. In return, ant colonies boost their numbers and more vigorously defend the life-sustaining foliage. (more…)

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Invasive crabs help Cape Cod marshes

Ecologists are wary of non-native species, but along the shores of Cape Cod where grass-eating crabs have been running amok and destroying the marsh, an invasion of a predatory green crabs has helped turn back the tide in favor of the grass. The counter-intuitive conclusions appear in a new paper in the journal Ecology.

PROVIDENCE, R.I. [Brown University] — Long vilified, invasive species can sometimes become an ecosystem asset. New Brown University research published online in the journal Ecology reports exactly such a situation in the distressed salt marshes of Cape Cod. There, the invasive green crab Carcinus maenas is helping to restore the marsh by driving away the Sesarma reticulatum crabs that have been depleting the marsh grasses. (more…)

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Southwest Regional Warming Likely Cause of Pinyon Pine Cone Decline, Says CU Study

Creeping climate change in the Southwest appears to be having a negative effect on pinyon pine reproduction, a finding with implications for wildlife species sharing the same woodland ecosystems, says a University of Colorado Boulder-led study.

The new study showed that pinyon pine seed cone production declined by an average of about 40 percent at nine study sites in New Mexico and northwestern Oklahoma over the past four decades, said CU-Boulder doctoral student Miranda Redmond, who led the study. The biggest declines in pinyon pine seed cone reproduction were at the higher elevation research sites experiencing more dramatic warming relative to lower elevations, said Redmond of CU’s ecology and evolutionary biology department.  (more…)

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Scientists Use Marine Robots to Detect Endangered Whales

Two robots equipped with instruments designed to “listen” for the calls of baleen whales detected nine endangered North Atlantic right whales in the Gulf of Maine last month. The robots reported the detections to shore-based researchers within hours of hearing the whales (i.e., in real time), demonstrating a new and powerful tool for managing interactions between whales and human activities.

The team of researchers, led by Woods Hole Oceanographic Institution (WHOI) scientists Mark Baumgartner and Dave Fratantoni, reported their sightings to NOAA, the federal agency responsible for enforcing the Marine Mammal Protection Act. NOAA Fisheries Service, in turn, put in place on Dec. 5 a “dynamic management area,” asking mariners to voluntarily slow their vessel speed to avoid striking the animals. (more…)

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Recreational Fishing Brings Salt Marsh Die-Off

As recreational fishing activity has reduced predators in many of Cape Cod’s salt marsh ecosystems, Sesarma crabs have feasted on grasses, causing dramatic die-offs of the marshes, according to a new study. The researchers assessed the “trophic cascade” in several experiments that also ruled out alternative explanations for the problem.

PROVIDENCE, R.I. [Brown University] — Recreational fishing is a major contributor to the rapid decline of important salt marshes along Cape Cod because it strips top predators such as striped bass, blue crabs, and smooth dogfish out of the ecosystem, according to new research by Brown University ecologists.

With far fewer predators in areas where recreational fishing is prevalent, native Sesarma crabs have had relatively free rein to eat salt marsh grasses, causing the ecosystem to collapse, said Mark Bertness, chair of Brown’s Department of Ecology and Evolutionary Biology and the paper’s senior author. He led a series of experiments and measurements published online in the journal Ecology that he said unavoidably implicate recreational fishing in marsh die-off. (more…)

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20 Years after Rio Earth Summit: Ecologists Call for Preservation of Planet’s Remaining Biological Diversity

ANN ARBOR, Mich.— Twenty years after the Earth Summit in Rio de Janeiro, 17 prominent ecologists are calling for renewed international efforts to curb the loss of biological diversity, which is compromising nature’s ability to provide goods and services essential for human well-being.

Over the past two decades, strong scientific evidence has emerged showing that loss of the world’s biological diversity reduces the productivity and sustainability of natural ecosystems and decreases their ability to provide society with goods and services like food, wood, fodder, fertile soils, and protection from pests and disease, according to an international team of ecologists led by the University of Michigan’s Bradley Cardinale. (more…)

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Over the Hump: Ecologists Use Power of Network Science to Challenge Long-Held Theory

*Global sampling of 48 sites on five continents yields unprecedented data set*

For decades, ecologists have toiled to nail down principles explaining why some habitats have many more plant and animal species than others.

Much of this debate is focused on the idea that the number of species is determined by the productivity of the habitat.

Shouldn’t a patch of prairie contain a different number of species than an arid steppe or an alpine tundra? (more…)

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What’s so Unique About the Tropics?

“Less than we thought,” researchers say in a new study providing insights into the distribution of biodiversity across the globe.

The temperate forests of Canada or Northern Europe may have much more in common with the tropical rainforests of Southeast Asia or South America than previously believed, according to a research group including a University of Arizona ecologist.

The assertion, published as the cover article in the journal Science, is focused on the concept of “beta-diversity” – a measure of the change in species composition between two sites, such as neighboring patches of forest. High beta-diversity means that two given sites have few species in common. (more…)

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