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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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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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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New Projection Shows Global Food Demand Doubling by 2050

*Increasing yield in poorer countries could decrease adverse environmental effects*

Global food demand could double by 2050, according to a new projection reported this week in the journal Proceedings of the National Academy of Sciences (PNAS).

The analysis also shows that the world faces major environmental challenges unless agricultural practices change.

Scientists David Tilman and Jason Hill of the University of Minnesota (UMN) and colleagues found that producing the amount of food needed could significantly increase levels of carbon dioxide and nitrogen in the environment, and may cause the extinction of numerous species. (more…)

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Mammals Grew 1,000 Times Larger After the Demise of the Dinosaurs

*NSF enabled the assembly of an international, interdisciplinary team that was the first to quantitatively document body size patterns over the past 100 million years*

Researchers have demonstrated that the extinction of dinosaurs some 65 million years ago paved the way for mammals to get bigger, about a thousand times larger than they had been when dinosaurs roamed the earth. The study, released in the journal Science, is the first to quantitatively document the patterns of body size of mammals after the existence of dinosaurs.

About the Image: The largest land mammals that ever lived, Indricotherium and Deinotherium, would have towered over the living African Elephant. Indricotherium lived during the Eocene to the Oligocene Epoch (37 to 23 million years ago) and reached a mass of 15,000 kg, while Deinotherium was around from the late-Miocene until the early Pleistocene (8.5 to 2.7 million years ago) and weighed as much as 17,000 kg. Image credit: NSF RCN IMPPS (more…)

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Climate Change May Create Tipping Points for Populations, Not Just Species

*Researchers measure survival, reproduction of thousands of arctic and alpine plants over six years*

As Earth’s climate warms, species are expected to shift their geographical ranges away from the equator or to higher elevations.

While scientists have documented such shifts for many plants and animals, the ranges of others seem stable. (more…)

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