Two major research projects are described here, the Konza Prairie LTER Site and comparison of the Konza Prairie to other grasslands.

Weathering of near-surface carbonate rocks under a pristine tallgrass prairie, the Konza Prairie LTER Site

A long-term data base comprises fifteen years of nearly monthly water sampling from which changes in weathering of Permian limestone and the influence of soil on groundwater chemistry are studied in an unplowed, mesic, mid-continental grassland. Results suggest an increase in below-ground partial pressure of CO₂, increasing weathering rates, and a change in predominantly weathered phases. These changes may have consequences for stream-, river-, and ocean chemistry.

Ongoing projects include seasonal variation in major elements and water-level response to vegetation use during dry periods.

Projects to follow on to currently published work include…

· trace element variation on seasonal and long-term time frames (REE, Pb, U, Zn and other transition elements)

· biogeochemical cycles of essential nutrients for plants

· boron and lithium isotope variation and relation to silicate weathering

· sources for Sr and Sr isotopes

· sources for Mg

· sources for SO₄ using S isotopes

· rock sources for N using N isotopes

· flux of CO₂ and H₂O from atmosphere to ground water using stable isotopes of C, O, and H

· daily water-level oscillation and slow overall decline in water level to interpret aquifer parameters on a centimeter scale

· and many more

Refereed articles

Wiley, Karen L., William C. Johnson, and G. L. Macpherson, in press (2006), Carbon isotope variation in modern soils of the tallgrass prairie—analogues for the interpretation of isotopic records derived from paleosols: Quaternary International.

Wood, Heather K. and G. L. Macpherson, 2005, Sources of Sr and implications for weathering of limestone under tallgrass prairie, northeastern Kansas: Applied Geochemistry, 20(12): 2325-2342. DOI: 10.1016/j.apgeochem.2005.08.002.

Macpherson, G. L., 2004, Field vs. lab pH in remote wells, Konza Prairie LTER site, and implications for limestone weathering: Proceedings, 11^th International Water-Rock Interaction Conference, June 27 – July 2, 2004, WRI-11, Saratoga Springs, New York, A. A. Balkema Publishers, New York, pg. 845-848.

Macpherson, G. L., 1996, Hydrogeology of thin-bedded limestones--the Konza Prairie LTER site, northeastern Kansas: Journal of Hydrology 186(1-4): 191-229.

Book Chapters, Guidebooks, Open-File Reports

Johnson, W.C., Macpherson, G.L., and Willey, K.L., 2004, Biochemical signatures within soils of the Konza Tallgrass Prairie LTER site, IN Mandel, R. (compiler), American Quaternary Association Guidebook, p. 2-3--2-7, Kansas Geological Survey Open-file Report 2004-33.

Gray, L. J., G. L. Macpherson, J. K. Koelliker, and W. K. Dodds, 1998, Chapter 11, Hydrology and aquatic chemistry: in A. K. Knapp, J. M. Briggs, and S. L. Collins, eds., Grassland Dynamics--Long-Term Ecological Research in Tallgrass Prairie, Oxford University Press, p. 159-176.

Macpherson, G. L. and M. A. Townsend, 1998, Chapter 5, Water chemistry and sustainable yield: in "Perspectives on Sustainable Development of Water Resources in Kansas", Bulletin, 239, Kansas Geological Survey, p. 117-157.

Abstracts

Macpherson, G. L., J. A. Roberts and D.A. Fowle, 2006, Increasing Groundwater CO2 and Other Solutes Under Tallgrass Prairie, Northeastern Kansas, USA: Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract V53D-1786.

Macpherson, G. L., 2006, Trends in water chemistry of shallow limestone aquifers: Konza Prairie LTER site, northeastern Kansas USA: GSA Abstracts with Programs 38(7):

Kissing, Kimberly Rae, and G. L. Macpherson, 2006, Short-term water-level fluctuations and long-term water-level decline at the Konza Prairie—drought or vegetation?: GSA Abstracts with Programs 38 ( 1):

Kissing, Kimberly Rae (advisor, G. L. Macpherson), 2006, Boron isotope ratios--Linking groundwater chemistry to landscape evolution of natural prairie environments: KU Undergraduate Research Symposium, poster presentation

Kissing, Kimberly Rae and G. L. Macpherson, 2006, Boron isotope ratios--Linking groundwater chemistry to landscape evolution of natural prairie environments: AWG Brown Bag presentation, 21 April 2006.

Kissing, Kimberly Rae (advisor: G. L. Macpherson), 2006, Short-term water-level fluctuations and long-term water-level decline at the Konza Prairie—drought or vegetation?: Honors Defense oral presentation and paper; May 12, 2006.

Kissing, Kimberly Rae, and G. L. Macpherson, 2006, Short-term water-level fluctuations and long-term water-level decline at the Konza Prairie—drought or vegetation?: GSA Abstracts with Programs 38 ( 1): .

Kim Kissing and G. L. Macpherson, 2005, Short-Term Water-Level Fluctuations and Long-Term Water-Level Decline at the Konza Prairie: Drought or Vegetation?: Osage Chapter of AWG Brown Bag Seminar, November 2005.

Kim Kissing and G. L. Macpherson,2005, Short-Term Water-Level Fluctuations and Long-Term Water-Level Decline at the Konza Prairie: Drought or Vegetation? : G-Hawk Student Symposium, October 2005.

Macpherson, G. L., W. C. Johnson, and L. W. Gatto, 2005, REE in Konza Prairie LTER Site(USA) soil—Allochthonous?: Geochimica et Cosmochimica Acta 69(105):A604.

Johnson, William C., G. L. Macpherson, Michael E. Ketterer, James M. Kaste, and Lawrence W. Gatto, 2004, Topographic variation in biogeochemical signatures within soils of the Konza Tallgrass Prairie LTER Site, Kansas: AAG (American Association of Geographers) 100^th annual meeting, 14-19 March 2004, Philadelphia PA.

Macpherson, G. L., and W. C. Johnson, 2004, Konza as a baseline for soil erosion and evaluation of the ¹³⁷Cs method —an update of a work in progress: 15^th Annual Konza LTER Workshop, March 6, 2004, Abstracts Volume, pg. 5-6.

Macpherson, G. L., William C. Johnson, Sheldon Landsberger, Michael E. Ketterer, Lawrence Gatto, and G. N. Blair, 2003, Nonradioactive cesium and rubidium as analogs for 137Cs behavior in soil at the Konza Prairie LTER site, northeastern Kansas, USA: Geological Society of America, Abstracts with Programs v. 35, no. 6.

Hunter, Lewis E. , D. L. Gebhart, G. L. Macpherson, W. C. Johnson, S. Landsberger, M. G. Hohmann, and L. Gatto, 2001, Detailed investigation of soil geochemistry to evaluate radioisotope distribution in prairie soils: Geological Society of America, Abstracts with Programs, 33(6): pg. A-366.

Macpherson, G. L. and H. Wood, 2001, Chemical weathering of carbonate phases at Konza Prairie LTER Site—Dependence on imported material: Geological Society of America, Abstracts with Programs, 33(6): pg. A-343.

Wood, Heather K., and G. L. Macpherson, 2000, “Punctuated equilibrium:” The effect of rainwater recharge on mineral weathering in thin limestone aquifers, north-central Kansas: Geological Society of America, Abstracts with Programs, 32(7): pg. A-483

Macpherson, G. L. and Simon Jackson, 1997, Trace elements in recent algal carbonate at the Konza LTER site, northeastern Kansas, determination by laser ablation microprobe (LAM) ICPMS: Geological Society of America, Abstracts with Programs, 29(6): p. A-175.

Macpherson, G. L., 1992, Variations in shallow ground-water chemistry, Konza Prairie LTER Site, Kansas, USA, 1991: 1992 AGU Spring Meeting, EOS 73(14): 126-127.

Macpherson, G. L., 1991, Time-series analysis of ground-water chemistry at Konza Prairie: Third Annual Konza Prairie LTER Workshop.

Macpherson, G. L., 1990, Chemical trends along ground-water flow paths, Cretaceous Dakota Formation aquifer, Kansas : Geological Society of America, Abstracts with Program, 22(7): 295.

Inman, Dan L., and G. L. Macpherson, 1990, Preliminary ground-water chemistry of the N4D watershed: Abstracts, Second Annual Konza Prairie LTER Workshop, p. 3.

Related Supervised Theses, Dissertations

Kissing, Kimberly Rae, 2006, Short-term water-level fluctuations and long-term water-level decline at the Konza Prairie—Drought or vegetation?: University of Kansas, unpublished senior honor’s thesis, 20 pp.

Wood, Heather, 2001, Seasonality and rates of mineral weathering in karst aquifers at the Konza Prairie: University of Kansas, unpublished MS thesis, 114 pp. (Supervisor: G. L. Macpherson)

Dee, Kato, 2001, Lead contamination and attenuation in a shallow monitoring well, Konza Prairie Long-Term Ecological Research site, Riley and Geary Counties, Kansas: University of Kansas, unpublished MS thesis, 124 pp. (Supervisor: G. L. Macpherson)

Weathering, Other Grasslands

Comparison of the Konza Prairie LTER Site with other grasslands is underway. First project compared element distributions in sequentially extracted soil samples. Amanda Wilson has so far presented results from Panama soils.

Abstracts

Wilson, Amanda, J. A. Roberts, and G. L. Macpherson, 2004, Weathering dynamics from selected soil sites on Barro Colorado Island, Panama: GSA Abstracts with Programs Vol. 36, No. 5, p. 494.