create_niche_model function

Create a food web based on the niche model

Function to generate a food web based on the niche model (Williams and Martinez, 2000) based on the number of species and connectance. Corrections from Allesina et al. (2008) are used.

create_niche_model(S, C)

Arguments

• S: integer, number of species.
• C: numeric, connectance i.e. the number of realized links over the all possible links.

Returns

A (square) matrix with zeros (no interaction) and ones (species j consume species i).

Details

If at least one species has not resource or consumer (i.e. it is an isolated species), another food web is generated, until a maximum of 100 iterations.

Examples

set.seed(123)
web_niche <- create_niche_model(30, .1)
image(t(web_niche))

References

Williams, R. J., & Martinez, N. D. (2000). Simple rules yield complex food webs. Nature, 404(6774), 180-183.

Allesina, S., Alonso, D., & Pascual, M. (2008). A general model for food web structure. science, 320(5876), 658-661.