T258 Sigma Gamma Epsilon Undergraduate Research (Posters)

Wednesday, 21 October 2009
9:00 AM - 6:00 PM
Hall A

REFORESTATION OR RESPONSE TO RISING ATMOSPHERIC CO2: INVESTIGATING TWO POSSIBLE MECHANISMS FOR THE INCREASE IN GROUNDWATER CO2 AT THE KONZA PRAIRIE, NORTHEASTERN KANSAS

Paper number: T258-2
Program: Technical Sessions
Time: 9:00 AM – 6:00 PM

Authors

Abstract

The Konza Prairie, a National Science Foundation Long-Term Ecological Research site and Biological Station, is an unplowed tallgrass prairie underlain by Early Permian-aged limestone-shale couplets that create sandwich-type aquifers. In an upland watershed at this site, two wells on the edge of the riparian zone on one side of the ephemeral stream draining the watershed show a 15-year increase in groundwater CO2 (Macpherson et al., 2008). The watershed has experienced invasion of woody species, especially near the riparian zone, and Liu et al. (2008) invoked the reforestation of a watershed in China as an explanation for increasing soil CO2. Therefore, we tested whether two other wells at the Konza Prairie that have not seen an increase in woody vegetation show changes in groundwater CO2 or not. Our findings confirm that, because the wells used for this study have experienced an increase in groundwater CO2 similar to the wells near the increasingly woody riparian zone, the increase in groundwater CO2 cannot be attributed to a change in vegetation, but may be a response to changing climate.

References

Macpherson G.L., Roberts J.A., Blair J.M., Townsend M.A., Fowle D.A. and Beisner K.R. (2008) Increasing shallow groundwater CO2 and limestone weathering Konza Prairie, USA. Geochimica et Cosmochimica Acta. 72, 5581-5599.

Liu, Z., Dreybrodt, W. and Wang, H. (2008) A possible important CO2 sink by the global water cycle. Chinese Science Bulletin. 53, 402-407.