agridat (version 1.16)

holland.arthropods: Counts of arthropods in a grid-sampled wheat field

Description

Counts of arthropods in a grid-sampled wheat field

Usage

data("holland.arthropods")

Format

A data frame with 63 observations on the following 8 variables.

row

row

col

column

n.brevicollis

species counts

linyphiidae

species counts

collembola

species counts

carabidae

species counts

lycosidae

species counts

weedcover

percent weed cover

Details

Arthropods were sampled at 30m x 30m grid in a wheat field near Wimborne, Dorest, UK on 6 dates in Jun/Jul 1996. Arthropod counts were aggregated across the 6 dates.

Holland et al. used SADIE (Spatial Analysis by Distance Indices) to look for spatial patterns. Significant patterns were found for N. brevicollis, Carabidae, Lycosidae. The Lycosidae counts were also significantly associated with weed cover.

Examples

# NOT RUN {
data(holland.arthropods)
dat <- holland.arthropods


# use log count to make it possible to have same scale for insects
if(require(reshape2) & require(lattice)){
  grays <- colorRampPalette(c("#d9d9d9","#252525"))
  dat2 <- melt(dat, id.var=c('row','col'))
  contourplot(log(value) ~ col*row|variable, dat2,
              col.regions=grays(7), region=TRUE,
              main="holland.arthropods - log counts in winter wheat")
}


# }
# NOT RUN {
  # individual species
  require(lattice)
  grays <- colorRampPalette(c("#d9d9d9","#252525"))
  contourplot(linyphiidae ~ col*row, dat, at=c(0,40,80,120,160,200), region=TRUE,
              col.regions=grays(5),
              main="holland.arthropods - linyphiidae counts in winter wheat")
  contourplot(n.brevicollis ~ col*row, dat, region=TRUE)
  contourplot(linyphiidae~ col*row, dat, region=TRUE)
  contourplot(collembola ~ col*row, dat, region=TRUE)
  contourplot(carabidae ~ col*row, dat, region=TRUE)
  contourplot(lycosidae ~ col*row, dat, region=TRUE)
  contourplot(weedcover ~ col*row, dat, region=TRUE)
# }
# NOT RUN {
# }