Climate of Our Future

Elevated Carbon Dioxide Spurs Shrub Growth

Science Daily — Shrubs far outgrew native grasses in Colorado rangeland when exposed to elevated levels of carbon dioxide (CO₂), according to a study published by Agricultural Research Service (ARS) scientists and cooperators at Colorado State University.

Plant physiologists Jack Morgan and Dan LeCain used open-top Chambers to evaluate the responses of native rangeland plant species exposed to a doubling of CO2 on the Colorado Shortgrass Steppe. (Credit: Scott Bauer)

The results suggest that rising CO₂ levels in the Earth’s atmosphere may be contributing to shifts in plant community dynamics, in which woody vegetation is favored over perennial forage grasses.

The study will be published in this week’s online edition of the Proceedings of the National Academy of Sciences. Plant physiologist Jack A. Morgan, research leader of the ARS Rangeland Resources Research Unit in Fort Collins, Colo., led the study. ARS is the U.S. Department of Agriculture’s chief scientific research agency. Keep reading

Climate Change Likely To Help With Groundwater Recharge

Science Daily — Elevated levels of carbon dioxide (CO₂) in the Earth’s atmosphere could seriously impact air, weather and vegetation. Now a scientist with the Agricultural Research Service (ARS) is taking a closer look at what could happen underground.

ARS scientists Mike Murphy (left) and Rob Erskine measure soil moisture in an Oklahoma pasture. Some of that moisture will drain through the soil beneath the root zone to recharge groundwater reserves. Hydrologist Tim Green’s simulation studies in Australia show that climate change impacts this process. (Credit: Tim Green)

If atmospheric CO₂ levels double within this century, as many climate models predict, some areas could experience large increases in the rate of groundwater recharge, the process by which water filters through the soil and enters aquifers. That’s the conclusion of a recent study conducted by ARS scientist Tim Green, a hydrologist in the agency’s … Keep reading.