This dataset contains the computed community effect matrix of the model in Figure 2 from Levins' 1996 paper (see references).
data(cem.levins)
A 4 by 4 (-1, 0, 1) matrix. The matrix is interpreted as the ith parameter has the indirect causal effect [i,j] on parameter j after the system stabilizes in response to a perturbation.
Levins, R. and Schultz, B. B. (1996) Effects of density dependence, feedback and environmental sensitivity on correlations among predators, prey and plant resources: Models and practical implications. Journal of Animal Ecology, 65(6),802-812. <tools:::Rd_expr_doi("10.2307/5678")>.
Puccia, C. J. and Levins, R. (1986) Qualitative Modeling of Complex Systems: An Introduction to Loop Analysis and Time Averaging. Cambridge: Harvard University Press. <tools:::Rd_expr_doi("10.4159/harvard.9780674435070")>.