Theory, Examples & Exercises
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Used as example dataset in Borcard et al. (2011); the dataset was first used in Borcard et al. (1992), and details are in Borcard & Legendre (1994).
(from Borcard et al. 2011)
Oribatid mites (Acari: Oribatida) are a very diversified group of small (0.2–1.2 mm) soil-dwelling, mostly microphytophagous and detritivorous arthropods. A well aerated soil or a complex substrate like Sphagnum mosses present in bogs and wet forests can harbour up to several hundred thousand (105) individuals per square metre. Local assemblages are sometimes composed of over a hundred species, including many rare ones. This diversity makes oribatid mites an interesting target group to study community–environment relationships at very local scales.
The example data set is composed of 70 cores of mostly Sphagnum mosses collected on the territory of the Station de biologie des Laurentides of Université de Montréal, Québec, Canada in June 1989. The data set comprises three files that contain the abundances of 35 morphospecies, 5 substrate and micritopographic variables, and the x-y Cartesian coordinates of the 70 cores.
Station de biologie des Laurentides, Université de Montréal, Quebec, Canada.
|Code||Description of variable|
|SubsDens||Substrate density (dry matter) [g dm-3]|
|WatrCont||Water content [g dm-3]|
|Substrate||Substrate [7 unordered classes]|
|Shrub||Shrubs [3 ordered classes]|
|Topo||Microtopography [Blanket - Hummock]|
mite <- read.delim ('https://raw.githubusercontent.com/zdealveindy/anadat-r/master/data/mite.txt') mite.env <- read.delim ('https://raw.githubusercontent.com/zdealveindy/anadat-r/master/data/mite_env.txt') mite.xy <- read.delim ('https://raw.githubusercontent.com/zdealveindy/anadat-r/master/data/mite_xy.txt')
or - data are in
vegan or in
# install.packages ('vegan') # install vegan if not installed yet on your computer library (vegan) data (mite) data (mite.env) # install.packages ('ade4') # install ade4 if not installed yet on your computer library (ade4) data (oribatid) # a list containing three components, check ?oribatid for details