@subsubheading Description

The @code{CO2} data set has 84 rows and 5 columns of data from an experiment
on the cold tolerance of the grass species Echinochloa crus-galli.

@subsubheading Format

@subsubheading Details

The CO2 uptake of six plants from Quebec and six plants from Mississippi was
measured at several levels of ambient CO2 concentration. Half the plants of
each type were chilled overnight before the experiment was conducted.

@subsubheading Source

Potvin, C., Lechowicz, M. J. and Tardif, S. (1990). The statistical
analysis of ecophysiological response curves obtained from experiments
involving repeated measures. @cite{Ecology}, 71, 1389–1400.

Pinheiro, J. C. and Bates, D. M. (2000). @cite{Mixed-effects Models
in S and S-PLUS}. New York: Springer.

@subsubheading Examples

@example
@INCLUDE_DATASET_EXAMPLE_SCRIPT{zCO2_1.m}
@end example
