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Mesquite Trees Displacing Southwestern Grasslands

By Guest PostMarch 21, 2012Environment, Natureatmosphere, biochemical pathway, bouteloua eriopoda, carbon dioxide, catalina mountains, changing climate, climate, climate data, desert, ecohydrology, ecosystems, eddy covariance tower, grama grass, grassland, greg barron gafford, groundwater, groundwater pool, mesquite tree, muhlenbergia porter, muhly, photosynthesis, predictions, prosopis velutina, rainfall, root system, san pedro river riparian area, santa rita mountains, seasonal precipitation, southeastern arizona, southwest, southwestern climate, sugars, temperature, university of arizona, warming climate, water resource, woody shrub

Mesquite trees and woody shrubs are better adapted than grasslands to a Southwestern climate predicted to shift toward higher temperatures and greater variability in rainfall, UA ecologists have discovered.

As the desert Southwest becomes hotter and drier, semi-arid grasslands are slowly being replaced by a landscape dominated by mesquite trees, such as Prosopis velutina, and other woody shrubs, a team of University of Arizona researchers has found.

In a “leaf-to-landscape” approach, the team combined physiological experiments on individual plants and measurements across entire ecosystems to quantify how well grasslands, compared to mesquite trees and woody shrubs, cope with heat and water stress across seasonal precipitation periods. (more…)

Milkweed Loss Hurts Monarchs

By Guest PostMarch 21, 2012Environment, Natureagricultural field, glyphosate herbicides, herbicide, john pleasants, karen oberhauser, Mexico, midwestern farm, milkweed, minnesota, monarch butterfly, monarchs, plant, university of minnesota, wildlife

*Loss of milkweed in Midwestern farm fields harms butterflies, a study shows*

If you’re a gardener, milkweed may not be at the top of your list.

But if you love Minnesota’s state insect—the monarch butterfly—maybe it should be.

Monarchs lay their eggs on milkweed, but the plant is disappearing from what used to be a prime reservoir: Midwestern farm fields. A new study by University of Minnesota monarch expert Karen Oberhauser and her Iowa State colleague John Pleasants ties a decade-long decline in monarch populations to the loss of milkweed from the corn and soybean fields that blanket the region. (more…)

Some Mammals Used Highly Complex Teeth to Compete With Dinosaurs

By Guest PostMarch 19, 2012Nature, Science3 d images, alistair evans, angiosperms, australia, back teeth, bumps, computed tomography, ct, cusps, dinosaur extinction, dinosaurs, event, extinction, finland, food, fossil, gregory p wilson, ian corfe, insect pollinators, jukka jernvall, mammal, mesozoic era, mikael fortelius, monash university, mountain range, multituberculates, Nature, paleontologist, peter smits, rodent, scanning, tooth surface, topography, tubercles, university of helsinki, university of washington, vince stricherz

Conventional wisdom holds that during the Mesozoic Era, mammals were small creatures that held on at life’s edges. But at least one mammal group, rodent-like creatures called multituberculates, actually flourished during the last 20 million years of the dinosaurs’ reign and survived their extinction 66 million years ago.

New research led by a University of Washington paleontologist suggests that the multituberculates did so well in part because they developed numerous tubercles (bumps, or cusps) on their back teeth that allowed them to feed largely on angiosperms, flowering plants that were just becoming commonplace. (more…)

Early Spring Drives Butterfly Population Declines

By Guest PostMarch 18, 2012Environment, Naturebutterfly population, carol boggs, caterpillars, climate change, colorado rocky mountains, david inouye, flower, life cycle, mormon fritillary butterfly, national science foundation, nectar, population, saran twombly, snowmelt, species, speyeria mormonia, university of maryland

“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…)

Discovery of Pine Beetles Breeding Twice in a Year Helps Explain Increasing Damage, CU Researchers Say

By Guest PostMarch 18, 2012Nature, Sciencealaska, american naturalist, attacking beetles, beetle epidemic, beetles, boulder, bugs, generation of beetles, higher elevation, jeffry mitton, lodgepole, mountain pine beetles, new mexico, pine trees, ponderosa, sangre de cristo, scott ferrenberg, tree killing beetles, university of colorado, warmer temperature, yukon territory

Long thought to produce only one generation of tree-killing offspring annually, some populations of mountain pine beetles now produce two generations per year, dramatically increasing the potential for the bugs to kill lodgepole and ponderosa pine trees, University of Colorado Boulder researchers have found.

Because of the extra annual generation of beetles, there could be up to 60 times as many beetles attacking trees in any given year, their study found. And in response to warmer temperatures at high elevations, pine beetles also are better able to survive and attack trees that haven’t previously developed defenses. (more…)

Hiding in Plain Sight, A New Frog Species With A ‘Weird’ Croak is Identified in New York City

By Guest PostMarch 15, 2012Nature, Scienceamphibians, brad shaffer, bronx, cathy newman, cryptic species, dna data, ecology, Environment, evolutionary biology, jeremy feinberg, joanna burger, leopard frog, leslie rissler, long snore, manhattan, marshes, mitochondrial dna, new frog species, new jersey, new york, new york city, odd frogs, ponds, rana, rapid chuckle, Rutgers University, skyscrapers, species, staten island, statue of liberty, uc davis, ucla, university of alabama, unusual frogs, weird rana, wilds, yankee stadium

In the wilds of New York City — or as wild as you can get so close to skyscrapers — scientists have found a new leopard frog species that for years biologists mistook for a more widespread variety of leopard frog.

While biologists regularly discover new species in remote rain forests, finding this one in the ponds and marshes of Staten Island, mainland New York and New Jersey — sometimes within view of the Statue of Liberty — is a big surprise, said the scientists from UCLA, Rutgers University, UC Davis, and The University of Alabama who worked together to make the unexpected discovery. (more…)

A Bird’s Song May Teach Us About Human Speech Disorders

By Guest PostMarch 7, 2012Nature, Sciencearea x, austin hilliard, autism, basal ganglia, bat species, biostatistics, brain, cortex, disorder, dolphins, elephants, elizabeth fraley, England, flying and perching, foxp2, genes, genetic equivalent, human genetics, human stuttering, julie miller, language, male zebra finches, master gene, neuroscience, sexually mature, small bird, social network, song, songbird, speech, stephanie white, steve horvath, stroke, stuart wolpert, tissue, vocalization, zebra finch

*UCLA scientists identify 2,000 important genes*

Can the song of a small bird provide valuable insights into human stuttering and speech-related disorders and conditions, including autism and stroke? New research by UCLA life scientists and colleagues provides reason for optimism.

The scientists discovered that some 2,000 genes in a region of the male zebra finch’s brain known as “Area X” are significantly linked to singing. More than 1,500 genes in this region, a critical part of the bird’s song circuitry, are being reported for the first time. Previously, a group of scientists including the UCLA team had identified some 400 genes in Area X. All the genes’ levels of expression change when the bird sings. (more…)

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

By Guest PostFebruary 28, 2012Nature, Sciencebergmann rule, coyote morphology, coyotes, ecogeographic principle, gray wolf, pleistocene coyotes, skeletons of wolves, solitary predators

*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. (more…)

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