the position between the ecotone of desiduous forests and prairy

more positive values of d13C indicate a spread of C4 prairy grasses and decline of C3 forest plants, more positive d18O indicates evaporation of soil water which is stronger in the prairy environment than in the forsest

effects of temperature on d18O in rainfall and alterations of the d18O of soil- and ground water due to evaporation

groundwater d18O, d13C of soil CO2 and DIC

Difference between the d13C of soil CO2 in areas with C3 and C4 vegetation

Denniston, R. F., Gonzalez, L. A., Baker, R. G., Asmerom, Y., Reagan, M. K., Edwards, R. L. and Alexander, E. C.: Speleothem evidence for Holocene fluctuations of the prairie-forest                 ecotone, north-central USA, The Holocene, 9(6), 671–676, doi:10.1191/095968399674716399, 1999.

d18O (SP04DEUS01A): interpretation4_scope: '' has been replaced by 'isotope'
d13C (SP04DEUS01A_d13C): interpretation3_scope: '' has been replaced by 'isotope'
d13C (SP04DEUS01A_d13C): interpretation4_scope: '' has been replaced by 'isotope'

"Oxygen isotope analyses were performed at the Isotope Laboratory, Institute of Karst Geology, Guilin, China, using a VG MM-903 gas mass spectrometer (for Dongge Cave D3 and D4 analyses, except for D4 between 15.81 ky and 9.98 ky); at the State Key Laboratory of Loess and Quaternary Geology, Insti- tute of Earth Environment, Xi?an, China, using a Finni- gan MAT 252 Kiel Device III (Dongge Cave D4 be- tween 15.81 and 9.98 ky); and on a Finnigan MAT 251 at the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (Hulu Cave H82 be- tween 15.34 and 16.30 ky before the present)."

sample D4 and H82 from Hulu Cave (Wang, et al., 2001) replicate, however "In detail, D3 and D4 do not replicate perfectly, with some times characterized by differences in  18O that are large as compared to analytical error but small compared to the amplitude of the record (Fig. 2). These discrepancies are likely due to kinetic effects, water/rock interactions, and/or differential evapora- tion of water at the land surface."