meta (version 6.2-1)

woodyplants: Elevated CO_2 and total biomass of woody plants

Description

Meta-analysis on effects of elevated CO_2 on total biomass of woody plants

This dataset has been used as an example in Hedges et al. (1999) to describe methods for the meta-analysis of response ratios. The complete dataset with 102 observations and 26 variables is available online as a supplement. Here only a subset of 10 variables is provided and used in the examples.

Format

A data frame with the following columns:

obsno	observation number
papno	database paper number
treat	treatment code
level	treatment level
n.elev	number of observations in experimental group (elevated CO_2-level)
mean.elev	estimated mean in experimental group
sd.elev	standard deviation in experimental group
n.amb	number of observations in control group (ambient CO_2-level)
mean.amb	estimated mean in control group
sd.amb	standard deviation in control group

References

Hedges LV, Gurevitch J, Curtis PS (1999): The meta-analysis of response ratios in experimental ecology. Ecology, 80, 1150--6

Examples

data(woodyplants)

# Meta-analysis of response ratios (Hedges et al., 1999)
#
m1 <- metacont(n.elev, mean.elev, sd.elev, n.amb, mean.amb, sd.amb,
  data = woodyplants, sm = "ROM", studlab = paste(obsno, papno, sep = " / "))
print(m1, prediction = TRUE)

# Meta-analysis for plants grown with low soil fertility treatment
#
m2 <- update(m1, subset = (treat == "fert" & level == "low"))
print(m2, prediction = TRUE)

# Meta-analysis for plants grown under low light conditions
#
m3 <- update(m1, subset = (treat == "light" & level == "low"))
print(m3, prediction = TRUE)