%0 Journal Article
%A Potvin, C.
%A Lechowicz, M.J.
%A Tardif, S.
%T The statistical analysis of ecophysiological response curves obtained from experiments involving repeated measures
%B Ecology
%D 1990
%V 71
%P 1389-1400
%N 4
%Z 00129658 (ISSN) Cited By (since 1996): 311 Export Date: 26 April
2007 Source: Scopus Language of Original Document: English; timestamp=(2007.12.05)
%X Physiological ecologists often analyze the responses of physiological
or biochemical traits to environmental factors. The data for such
a response curve typically are gathered by sequential sampling of
the same plant or animal; analysis should explicitly allow for this
repeated-measures design. The authors address statistical treatment
of response curves and illustrate the correct alternatives that
are available. Four different statistical methods for analyzing
response curves are considered: analysis of variance with repeated
measures (ANOVAR), multivariate analysis of variance with repeated
measures (MANOVAR), a nonparametric split-plot analysis (NP split-plot)
and parametric comparison of models fitted to the data by nonlinear
regression. Analyses of the CO2 dependence of photosynthesis in
the C4 grass Echinochloa crus-galli following chilling are used
as examples of these different methods. ANOVAR, potentially the
most powerful analysis, makes stringent assumptions about the variance-covariance
structure of the data. Within limits these assumptions can be relaxed
and a corrected significance level used. When the variance-covariance
structure badly violates the ANOVAR assumptions, MANOVAR or NP split-plot
are viable alternatives. Use of MANOVAR frequently is limited by
small sample sizes and the tendency for the number of levels of
the treatment factor to exceed the sample size. The NP split-plot
is based on simple assumptions and could be widely used. Comparison
of curves fitted by nonlinear regression is also distribution free
and provides an interesting alternative when responses are amenable
to fitting. -from Authors
%K analysis of variance carbon dioxide photosynthesis response curve
split-plot analysis Echinochloa crus-galli
%# brugerolles
%F PotvinLechowiczTardif1990
%3 BibTeX type = ARTICLE