Los Alamos National Laboratory

Open-Air Laboratories

For over a decade, the U.S. Department of Energy has managed a collection of large, outdoor field experiments to monitor the effects of elevated CO2 levels in real ecosystems. Observing stations and CO2 injectors were established in a variety of ecological zones, and researchers have been collecting empirical data on how the extra greenhouse gas in the air affects the plants and other life present.

Sweetgum plantation photo

Sweetgum plantation in Tennessee
photo courtesy of Steve Eberhardt / ORNL

Kuske's team takes its soil samples from six of these study sites, chosen to span a diverse range of habitats within the United States. In most of the sites, plant growth increases in response to the elevated CO2. But how much of that carbon remains locked up in plant matter, safely out of the atmosphere? That depends on the microbes in the soil, and it is one of Kuske's principal research objectives to assess the microbes' response to the added CO2, an effort that began in earnest about a year ago. One of the major challenges is to identify trends in microbial populations that are important at the landscape level, which requires many samples and a blend of metagenomic and other measurements.

Desert shrubs, grasses, and soil crust in Nevada photo

Desert shrubs, grasses, and soil crust in Nevada
photo courtesy of Lynn Fenstermaker

Kuske's early results show that a soil community's response to the enriched CO2 atmosphere is varied and complex; each ecosystem has a different response pattern. At some sites, the total microbial biomass goes up or down. In some cases, the fungal populations appear to change the most, while in others it's the bacteria. In the Nevada desert site, for instance, there was no observed change in fungal populations, but a population of bacteria called cyanobacteria diminished substantially. This may be significant because cyanobacteria in arid lands are responsible for many of the services normally provided by plants elsewhere: absorbing carbon from the air through photosynthesis, fertilizing, and stabilizing the soil against erosion. Arid lands—including deserts, arid grasslands, and shrub lands—make up one-third of all the land on Earth.

Palmetto and scrub oak grove in Florida photo

Palmetto and scrub oak grove in Florida
photo courtesy of Bert Drake

Estuary marsh grasses in Maryland
photo

Estuary marsh grasses in Maryland
photo courtesy of Mark Sigrist

PPine forest in North Carolina 
photo

Pine forest in North Carolina
photo courtesy of Yavor Parashkevov

Aspen, maple, birch, and poplar plantation in Wisconsin photo

Aspen, maple, birch, and poplar plantation in Wisconsin photo courtesy of David F. Karnosky

In this issue...

Contact Us | Careers | Bradbury Science Museum | Emergencies | Inside LANL | Maps | Site Feedback | SSL Portal | Training

Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA © Copyright 2014 LANS, LLC All rights reserved | Terms of Use | Privacy Policy