Tag Archives: catalina mountains

Mesquite Trees Displacing Southwestern Grasslands

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…)

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Asteroid 2011 AG5 – A Reality Check

Asteroid 2011 AG5 has been receiving a lot of attention lately because of a very unlikely scenario which would place it on an Earth-interception course 28 years from now. Here is a scientific reality check of this relatively nondescript space rock which is currently ranked a “1” on the 1 to 10 Torino Impact Hazard Scale

As of Feb. 26, 2012, asteroid 2011 AG5 is one of 8,744 near-Earth objects that have been discovered. It is approximately 460 feet (140 meters) in size and its orbit carries it as far out as beyond Mars’ orbit and as close to the sun as halfway between Earth and Venus. It was discovered on Jan. 8, 2011, by astronomers using a 60-inch Cassegrain reflector telescope located at the summit of Mount Lemmon in the Catalina Mountains north of Tucson, Arizona. (more…)

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