Tag Archives: saran twombly

Where Does Charcoal, or Black Carbon, in Soils Go?

Scientists find surprising new answers in wetlands such as the Everglades

Scientists have uncovered one of nature’s long-kept secrets–the true fate of charcoal in the world’s soils.

The ability to determine the fate of charcoal is critical to knowledge of the global carbon budget, which in turn can help understand and mitigate climate change.

However, until now, researchers only had scientific guesses about what happens to charcoal once it’s incorporated into soil. They believed it stayed there.

Surprisingly, most of these researchers were wrong. (more…)

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Where Have All the Hummingbirds Gone?

Glacier lilies and broad-tailed hummingbirds out of sync

The glacier lily as it’s called, is a tall, willowy plant that graces mountain meadows throughout western North America. It flowers early in spring, when the first bumblebees and hummingbirds appear.

Or did.

The lily, a plant that grows best on subalpine slopes, is fast becoming a hothouse flower. In Earth’s warming temperatures, its first blooms appear some 17 days earlier than they did in the 1970s, scientists David Inouye and Amy McKinney of the University of Maryland and colleagues have found. (more…)

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Evolving to Fight Epidemics: Weakness Can Be an Advantage

*Less resistance can sometimes be better than more–at least in a freshwater lake*

When battling a deadly parasite epidemic, less resistance can sometimes be better than more, a new study suggests.

A freshwater zooplankton species known as Daphnia dentifera endures periodic epidemics of a virulent yeast parasite that can infect more than 60 percent of the Daphnia population.

During these epidemics, the Daphnia population evolves quickly, balancing infection resistance and reproduction. (more…)

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Early Spring Drives Butterfly Population Declines

“Ahead-of-time” snowmelt triggers chains of events in the Mormon Fritillary butterfly

Early snowmelt caused by climate change in the Colorado Rocky Mountains snowballs into two chains of events: a decrease in the number of flowers, which, in turn, decreases available nectar. The result is decline in a population of the Mormon Fritillary butterfly, Speyeria mormonia.

Using long-term data on date of snowmelt, butterfly population sizes and flower numbers at the Rocky Mountain Biological Laboratory, Carol Boggs, a biologist at Stanford University, and colleagues uncovered multiple effects of early snowmelt on the growth rate of an insect population. (more…)

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Coyotes “Shrank,” Wolves Did Not, After Last Ice Age and Megafaunal Extinctions

*Once large and wolf-like, coyotes ultimately became much smaller*

When the last ice age ended more than 10,000 years ago, many large species of mammals went extinct and others underwent changes in appearance.

But what caused evolutionary changes to take place in the mammals that remained alive?

A study by Julie Meachen of the National Science Foundation (NSF) National Evolutionary Synthesis Center and Josh Samuels of the John Day Fossil Beds National Monument reveals that gray wolves and coyotes, once more similar in size, took the extinction in different strides. (more…)

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Prehistoric Predators with Supersized Teeth Had Beefier Arm Bones

*Combination of colossal canines and forceful forelimbs arose repeatedly over time*

The toothiest prehistoric predators also had beefier arm bones, according to results of a study published today in the journal Paleobiology.

Saber-toothed tigers may come to mind, but these extinct cats weren’t the only animals with fearsome fangs.

Take the false saber-toothed cats–also known as nimravids–and their catlike cousins, a family of carnivores called the barbourofelids. (more…)

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Acid Rain Poses a Previously Unrecognized Threat to Great Lakes Sugar Maples

ANN ARBOR, Mich.— The number of sugar maples in Upper Great Lakes forests is likely to decline in coming decades, according to University of Michigan ecologists and their colleagues, due to a previously unrecognized threat from a familiar enemy: acid rain.

Over the past four decades, sugar maple abundance has declined in some regions of the northeastern United States and southeastern Canada, due largely to acidification of calcium-poor granitic soils in response to acid rain. (more…)

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