H2fun: Specialisation of a bipartite web.

Description

Calculates the overall level of specialisation of all partners in a bipartite web.

Usage

H2fun(web)

Arguments

web

A matrix representing the interactions observed between higher trophic level species (columns) and lower trophic level species (rows). Usually this will be number of pollinators on each species of plants or number of parasitoids on each species o

Value

H2The H2'-value for the web matrix.
H2minHeuristic minimum H2-value for the web matrix.
H2maxHeuristic maximum H2-value for the web matrix.
H2uncorrUncorrected H2-values (before ranging between min and max), rounded to three digits.

encoding

latin1

Details

H2' is an index describing the level of specialisation, or should one say: selectiveness, of an entire bipartite network (Bl�thgen et al. 2006). It describes to which extent observed interactions deviate from those that would be expected given the species marginal sums. The more selective a species, the larger is H2' for the web. H2' is an extension of d' (see dfun) for the entire network. Check there for details on finding maximum and minimum H2 values for a given web. For internet implementation see also: http://nils.mib.man.ac.uk/~nils/stat/

References

Bl�thgen, N., Menzel, F. and Bl�thgen, N. 2006 Measuring specialization in species interaction networks. BMC Ecology 6, 9

Examples

Run this code

data(Safariland)
H2fun(Safariland)

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