Soil microbial activity and N availability with elevated CO2 in Mojave Desert soils
Billings, Sharon A.
Schaeffer, Sean M.
American Geophysical Union
Scholarly/refereed, publisher version
This published article is © American Geophysical Union and can found on the publisher's website at http://dx.doi.org/10.1029/2003GB002137
MetadataShow full item record
We examined the effects of elevated CO2 on soil nitrogen (N) dynamics in the Mojave Desert by measuring plant N isotope composition (δ15N), soil microbial biomass N, soil respiration, resin-available N, and C and N dynamics during soil incubations. With elevated CO2, foliage of Larrea tridentata and Krameria erecta had mean δ15N 2.1 and 1.1‰ higher with elevated CO2, respectively, and elevated CO2 increased microbial biomass N in dry soils under a perennial grass (6.8 ± 1.4 versus 3.7 ± 0.3 μg/g). Elevated CO2 significantly increased cumulative resin-available N in the field by 12%, driven by available soil moisture. Rates of soil respiration with elevated CO2 were sporadically higher under Pleuraphis and Larrea. Soils under shrubs had greater potential net N mineralization (102.6 ± 24.2 μg/g) than soils under grasses and in plant interspaces (40.0 ± 9.69 μg/g). Rates of recalcitrant N turnover in soil incubations were related to soil substrate availability. Results indicate that shifts in soil microbial structure and/or activity may occur with elevated CO2 and may result in increases in plant-available N when soil moisture is available.
Billings, S. A., S. M. Schaeffer, and R. D. Evans (2004), Soil microbial activity and N availability with elevated CO2 in Mojave Desert soils, Global Biogeochem. Cycles, 18, GB1011, http://dx.doi.org/10.1029/2003GB002137
Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.
We want to hear from you! Please share your stories about how Open Access to this item benefits YOU.