southwest – Shamskm: A site to exchange knowledge and solutions

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

By Guest PostFebruary 18, 2013Environmentbird, black bears, black chinned hummingbirds, boulder, climate change, climate warming trend, cone initiation, creeping climate change, crossbill, dramatic warming, drought, ecologists, ecosphere study, ecosystems, environmental stimulus, fire, forcella, frank forcella, germination, growing season, impact, increases in temperatures, insects, jeffry mitton, lower elevations, mammal species, masting events, miranda redmond, negative effect, new mexico, northern arizona, northwestern oklahoma, nut carrying cones, nutcrackers, pinyon pine, pinyon pine reproduction, pinyon pine seedlings, pollination, precipitation, season, southwest, temperature, university, university of colorado, us tree, woodland ecosystems

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…)

Droughts are Pushing Trees to the Limit

By Guest PostSeptember 8, 2012Environmentaerial surveys, atmospheric sponge, borderland, carbon dioxide, catastrophic disruption, climate change, deficit, drought, ecological disturbance, elevation, embolism, forest service, four corners, greenhouse experiment, growing season, high plains, index, jeremy weiss, jonathan overpeck, julio betancourt, leaf water, Mexico, moisture, mountainous terrain, photosynthesis, plant growth, precipitation, regional warming, southwest, stomates, temperatures rise, university of arizona, US, vapor pressure, vicious circle, weather data, wildfires

Droughts in the Southwest made more severe by warming temperatures are putting plants in stressful growing conditions, a new study has found, identifying an increasingly water-thirsty atmosphere as a key force that sucks moisture from plants, leading to potentially higher stress – especially in mid and low elevations.

As temperatures rise and droughts become more severe in the Southwest, trees are increasingly up against extremely stressful growing conditions, especially in low to middle elevations, University of Arizona researchers report in a study soon to be published in the Journal of Geophysical Research Biogeosciences.

Lead author Jeremy Weiss, a senior research specialist in the UA department of geosciences, said: “We know the climate in the Southwest is getting warmer, but we wanted to investigate how the higher temperatures might interact with the highly variable precipitation typical of the region.” (more…)

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…)

Uncertain Future for Joshua Trees Projected with Climate Change

By Guest PostMarch 27, 2011Environment, Naturecalifornia, climate change, climate warming, climatic tolerances, ecologis, ecology, fossil record, jon eischeid, joshua trees, ken cole, kenneth cole, kirsten ironside, models of future climate, mojave desert, nevada, north american yucca, packrats, shasta ground sloth, southwest, squirrels, state of the art climate models, temperature

FLAGSTAFF, Ariz. — Temperature increases resulting from climate change in the Southwest will likely eliminate Joshua trees from 90 percent of their current range in 60 to 90 years, according to a new study led by U.S. Geological Survey ecologist Ken Cole.

The research team used models of future climate, an analysis of the climatic tolerances of the species in its current range, and the fossil record to project the future distribution of Joshua trees. The study concludes that the species could be restricted to the northernmost portion of its current range as early as the end of this century. Additionally, the ability of Joshua trees to migrate via seed dispersal to more suitable climates may be severely limited. (more…)

Drier Conditions Projected to Accelerate Dust Storms in the Southwest

By Guest PostMarch 3, 2011Environmentagricultural productivity, arches, arid landscapes, biological soil crusts, canyonlands national parks, climate change, cyanobacteria, drier conditions, drought conditions, dust storm, grasslands, magnitude of runoff, perennial vegetation cover, rates of dust emission, sediment transport, semiarid and arid environments, seth munson, shrublands, southeastern utah, southwest, wind erosion

MOAB, Utah — Drier conditions projected to result from climate change in the Southwest will likely reduce perennial vegetation cover and result in increased dust storm activity in the future, according to a new study by scientists with the U.S. Geological Survey and the University of California, Los Angeles.

The research team examined climate, vegetation and soil measurements collected over a 20-year period in Arches and Canyonlands National Parks in southeastern Utah. Long-term data indicated that perennial vegetation in grasslands and some shrublands declined with temperature increases. The study then used these soil and vegetation measurements in a model to project future wind erosion. (more…)

Tag Archives: southwest

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

Droughts are Pushing Trees to the Limit

Mesquite Trees Displacing Southwestern Grasslands

Uncertain Future for Joshua Trees Projected with Climate Change

Drier Conditions Projected to Accelerate Dust Storms in the Southwest