GRASSLAND PRODUCTIVITY AND CARBON DYNAMICS: CONSEQUENCES OF CHANGE IN ATMOSPHERIC CO2, PRECIPITATION, AND PLANT SPECIES COMPOSITION, ...
Location: Grassland, Soil and Water Research Laboratory
Title: Rising atmospheric CO2 effects on productivity and plant composition differs among soils in southern plains tallgrass prairie
Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 22, 2011
Publication Date: August 7, 2011
Citation: Fay, P.A., Polley, H.W., Jin, V.L., Gill, R.A., Jackson, R.B., Way, D. 2011. Rising atmospheric CO2 effects on productivity and plant composition differs among soils in southern plains tallgrass prairie. In: Proceedings of the Ecological Society of America, Austin, Texas. OOS 33-5.
Rising atmospheric CO2 concentrations are expected to alter grassland ecosystem structure and function, and may have contributed to the current level of woody encroachment. But critical questions remain regarding 1) how much change in productivity or species composition may occur with near-future increases in CO2, compared to changes caused by past CO2 increases; and 2) how ecosystem responses might vary among soils across the landscape. Soils differ in water holding capacity, organic matter, and other properties crucial to primary productivity, and plant species differ in physiological efficiency and drought tolerance. These differences should have important consequences for species change and soil water balance as CO2 increases. We conducted a five year experiment in which we imposed a subambient to enriched gradient in CO2 concentration on a tallgrass prairie. Plots were established in weighing lysimeters containing an upland clay, a lowland clay, or a sandy alluvial soil representative of those in Southern Plains tallgrass prairie. We hypothesized that elevated CO2 would cause varying degrees of increase in aboveground net primary productivity (ANPP) among the soils, favor more mesic species, and increase soil water availability, especially on coarser soils with lower water holding capacity.