Fig 1.
Map showing Singapore’s freshwater environment, which comprises a highly inter-connected network of man-made reservoirs, rivers, streams, canal and drains.
1. Pulau Seletar, 2. Pulau Ubin, 3. Pulau Tekong, 4. St. John’s, Lazarus and Kusu islands, 5. Sentosa, 6. Pulau Sebarok, 7. Pulau Bukom, 8. Semakau Landfill, 9. Pulau Sudong, 10. Pulau Pawai, and 11. Pulau Senang.
Fig 2.
Relative variable importance of attributes (other attributes had relatively low variable importance and fluctuated about zero).
Fig 3.
Receiver operating characteristic curves for (a) the full random forest model containing all 21 species attributes, (b) reduced random forest model without attributes year of introduction and invasion history, and (c) the training and test samples used to account for circularity.
Table 1.
Attributes identified to be important predictors of establishment in random forest model.
Standard errors are given for continuous data in parentheses.
Fig 4.
Receiver operating characteristic curves for models constructed to assess model accuracy in predicting for establishment likelihood.
(a) The full random forest model containing all 21 species attributes. (b) Reduced random forest model without attributes year of introduction and invasion history. (c) The training and test samples used to account for circularity.