ISSN:
1573-5036
Keywords:
blue grama
;
Bouteloua gracilis
;
C4 grass
;
CO2 enrichment
;
mycorrhizae
;
nitrogen
;
phosphorus
;
VAM
;
water relations
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract In order to better elucidate fixed-C partitioning, nutrient acquisition and water relations of prairie grasses under elevated [CO2], we grew the C4 grass Bouteloua gracilis (H.B.K.) lag ex Steud. from seed in soil-packed, column-lysimeters in two growth chambers maintained at current ambient [CO2] (350 μL L−1) and twice enriched [CO2] (700 μL L−1). Once established, plants were deficit irrigated; growth chamber conditions were maintained at day/night temperatures of 25/16°C, relative humidities of 35%/90% and a 14-hour photoperiod to simulate summer conditions on the shortgrass steppe in eastern Colorado. After 11 weeks of growth, plants grown under CO2 enrichment had produced 35% and 65% greater total and root biomass, respectively, and had twice the level of vesicular-arbuscular mycorrhizal (VAM) infection (19.8% versus 10.8%) as plants grown under current ambient [CO2]. The CO2-enriched plants also exhibited greater leaf water potentials and higher plant water use efficiencies. Plant N uptake was reduced by CO2 enrichment, while P uptake appeared little influenced by CO2 regime. Under the conditions of the experiment, CO2 enrichment increased root biomass and VAM infection via stimulated growth and adjustments in C partitioning below-ground.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00009970
