mite {codep}

The Oribatid Mite Data Set

Description

Borcard et al's oribatid mite community composition from Lac Geai, Canada.

Usage

data(mite)

Format

Contains three matrices:

mite.species

The abundance of 35 morpho-species of oribatid mites (Acari).

mite.env

14 environmental variables (quantitative and binary).

mite.geo

The relative coordinates of the samples.

Details

Values in mite.species are counts of individuals of each of the morpho-species obtained from 5 cm diameter cores going from the surface of the peat down to a depth of 7 cm. See Bordard & Legendre (1994) and reference therein for details about sample treatment and species identification.

'mite.env' contains two quantitative variables, namely the substratum density (g/L) and water content (percent wet mass over dry mass), in addition to 12 dummy variables. The first seven represent the composition of the substratum: Sphagnum magellacinum (with a majority of S. rubellum), S. rubellum, S. nemorum, (with a majority of S. augustifollium), S. rubellum + S. magellicum (in equal proportions), lignous litter, bare peat, and interface between Sphagnum species. The next three dummy variables represent the presence and abundance of shrubs (Kalmia polifolia, K. angustifolia, and Rhododentron groenlandicum): none, few, and many. The last two dummy variables represent the microtopography of the peat: blanket (flat) or hummock (raised).

'mite.geo' contains the location of the samples, in meters, with respect to the sampling grid. Point (0,0) is the lower left end of the plot for an observer looking from the shore towards the water. The 'x' coordinate is the offset along the shore (from left to right) while the 'y' coordinate is the offset from the shore while moving towards the water (See Borcard & Legendre, 1994, Fig. 1 for details on the sampling area).

Source

Daniel Borcard, Département de sciences biologiques, Université de Montréal, Montréal, Québec, Canada.

References

Borcard, D. & Legendre, P. 1994. Environmental control and spatial structure in ecological communities: an example using Oribatid mites (Acari, Oribatei). Environ. Ecol. Stat. 1: 37-61

See Also

Borcard, D.; P. Legendre & P. Drapeau. 1992. Partialling out the spatial component of ecological variation. Ecology 73: 1045-1055

Legendre, P. 2005. Species associations: the Kendall coefficient of concordance revisited. Journal of Agricultural, Biological and Environmental Statistics 10: 226-245

Borcard, D.; Gillet, F. & Legendre, P. 2011. Numerical Ecology with R. Springer, New-York, NY, USA.

Examples

data(mite)
summary(mite.species)
summary(mite.env)
summary(mite.geo)