PARENT SESSION
Poster Session 5: Climate Dynamics
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Quantifying the Effects of Interannual Climate Variability on Plant Biomass in an Oklahoma Tall-grass Prairie Ecosystem.
Farnady, Annmarie*,1, Arnone, John1, Verburg, Paul1, 1 Desert Research Institute, Reno, NV, U.S.A.
ABSTRACT- We are studying the effects of changing year-to-year climate variability and its effect on the structure and function of a tall-grass prairie ecosystem of the North American Great Plains. The underlying ecological mechanisms of this year-to-year variability are generally believed to result from precipitation- and temperature-driven shifts in species competition. We will be focusing on the change in biomass of the plants and the potential role of any change in responses. This experiment was run in the EcoCELLs, four temperature-controlled greenhouses that each contain three separate monoliths of plants. All four greenhouses contain samples of undisturbed prairie that were collected from the same area of Oklahoma. During the first year, all four EcoCELLs were maintained at an average temperature determined from measurements taken at the Oklahoma site. During the second year, the temperature in two of the EcoCELLs was elevated to simulate an anomalously warm year while the other two were kept at the normal average temperature. During the third year, the anomalously warm EcoCELLs were returned to average Oklahoma temperatures. We hypothesized that these changes may affect the interactions between species, with an increase in the biomass of one type of plant being linked to a decrease in another type of plant, which may have a major impact on the biodiversity of the community as a whole, and alter the function of the ecosystem as well as the services that the ecosystem provides. Our specific hypothesis is that the biomass will be affected negatively by the temperature change. A secondary hypothesis is that the invasive plants present in the EcoCELLs will be positively affected by the change in climate. Our primary hypothesis was disproved over time, as the total biomass in the experimental, heated EcoCELLs decreased during the treatment year but recovered to a state comparable to that of the control EcoCELLs during the post-treatment year.
Key words: interannual climate variability, biomass, tall-grass prairie