Ecological Archives E087-081-A2

C. E. Cáceres, S. R. Hall, M. A. Duffy, A. J. Tessier, C. Helmle, and S. MacIntyre. 2006. Physical structure of lakes constrains epidemics in Daphnia populations. Ecology 87:1438–1444.

Appendix B. Results from the regression tree analyses. Because some of our metrics varied among years (infection prevalence, host density, Fee’s probability) whereas others (phosphorus, surface area, maximum depth, mean depth, depth ratio) were constant among years, we fit two models. Panel A shows the result of the model that included each lake once with the three-year average for density and prevalence of infection. Panel B shows the results from the second model which considered each annual epidemic to be a unique event. We used the least squares loss function with a stopping rule of four cases per terminal node. Symbols are shaded based on their grouping in the terminal nodes. Numbers above boxes indicate cut values.



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