Bakwin , P. S. , Tans , P. R , White , J. W. C. and Andres , R. J . 1998 . Determination of the isotopic (C-13/C-12) dis-crimination by terrestrial biology from a global network of observations . Global Biogeochem. Cycles 12 , 555 – 562 .
Bevington , P. R. and Robinson , D. K . 1992. Data reduction and error analysis for the physical sciences, McGraw Hill, Boston.
Boggs , P. T. , Byrd , R. H. and Schnabel , R. B . 1987 . A stable and efficient algorithm for nonlinear orthogonal distance regression , SIAM J. Sci. Statist. Comput . 8 , 1052 – 1078 .
Buchmann , N. , Guehl , J. M. , Barigah , T. S. and Ehleringer , J. R . 1997 . Interseasonal comparison of CO2 concentrations, isotopic composition, and carbon dynamics in an Amazo-nian rainforest (French Guiana) . Oecologia 110 , 120 – 131 .
Conway , T. J. , Tans , P. R , Waterman , L. S. , Thoning , K. W. , Kitzis , D. R. , Massarie , K. A. and Zhang , N . 1994 . Evidence for interannual variability of the carbon cycle for the National Oceanic and Atmospheric Administra-tion/Climate Monitoring Diagnostics Laboratory Global Air Sampling Network . J. Geophys. Res . 99 , 22 831-22 855 .
Keeling , C. D . 1961 . The concentrations and isotopic abun-dances of atmospheric carbon dioxide in rural and marine air . Geochim. Cosmochim. Acta 24 , 277 – 298 .
Miller , J. B. , Tans , P. P. , White , J. W. C. , Conway , T. J. and Vaughn , B. W . 2002. The atmospheric signal of terres-trial isotopic discrimination and its implication for carbon fluxes. Tellus 55B, this issue.
Pataki , D. E. , Ehleringer , J. R. , Flanagan , L. B. , Yalcir , D. , Bowling , D. , Still , C. J. , Buchmann , N. , Kaplan , J. O. and Berry , J. A. 2002. The application and interpretation of Keeling plots in terrestrial carbon cycle research. Global Biogeochem. Cycles (in press).
Press , W. H. , Teukolsky , S. A. , Vetterling , W. T. and Flannery , B. P . 1992. Numerical recipes in C, Cambridge University Press, New York.
Ricker , 1973 . Linear regressions in fishery research . J. Fish. Res. Board Can . 30 , 409 – 434 .
Sokal , R. R. and Rohlf , F. J . 1995 . Biometry: the princi-ples and practice of statistics in biological research, W . H. Freeman and Co ., New York .
Sprent and Dolby , 1980 . The geometric mean functional re-lationship . Biometrics 36 , 547 – 550 .
Tans , P. P . 1980 . On calculating the transfer of carbon-13 in resevoir models of the carbon cycle . Tellus 32 , 464 – 469 .
Thoning , K. W. , Tans , P. P. and Komhyr , W. D . 1989 . At-mospheric carbon dioxide at Mauna Loa Observatory 2. Analysis of the NOAA GMCC data, 1974-1985 . J. Geo-phys. Res . 94 , 8549 – 8565 .
Trolier , M. , White , J. W. C. , Tans , P. R , Massarie , K. A. and Gemery , P. A . 1996 . Monitoring the isotopic compo-sition of atmospheric CO2: Measurements from the NOAA global air sampling network . J. Geophys. Res . 101 , 25 897-25 916 .
Yakir , D. and Wang , X.-F . 1996 . Fluxes of CO2 and water be-tween terrestrial vegetation and the atmosphere estimated from isotope measurements . Nature 380 , 515 – 517 .
York , 1966 . Least-squares fitting of a straight line . Can. J. Phys . 44 , 1079 – 1086 .