On the form of species–area relationships in habitat islands and true islands

Abstract

In Matthews et al. (2016), errors were found in Abstract section on page 841 and power (log–log) model section on page 852, due to the following reasons: To compare c-values (from the `power log-log species–area relationship model), the area units should be the same. However, in the analyses comparing the c-values of the power model between habitat islands and different categories of true islands, the authors mistakenly did not convert the island areas of the habitat island datasets (originally in ha) into km2 (the area units of the true island datasets). When the c-values were calculated after converting habitat island areas to km2, the median habitat island c-value was 3.16 (Q1 and Q3 = 2.33 and 4.10). c-values were significantly lower for oceanic islands (median = 1.45; Q1 and Q3 = 0.33 and 2.45; P < .001), continental-shelf islands (median = 2.20; Q1 and Q3 = 0.80 and 3.39; P < .001), and inland water-body islands (median = 2.81; Q1 and Q3 = 1.60 and 3.78; P = .04) whereas in the original article we (incorrectly) reported that c-values were significantly higher for inland water-body islands, than for habitat islands. Hence, in the Abstract section, under results, the fourth sentence should say “Average c-values were significantly lower for oceanic islands, inland water body islands, and continental-shelf islands, than for habitat islands.” In addition, making these changes affect two parts of two figures in the supporting information Appendix S3 (Figures S2a and S6a). The new figures indicate that, when converting habitat island areas to km2, the mean habitat island c-value increases slightly; this makes sense as you can fit more species in 1 km2 than 1 ha. All of the remaining analyses in the paper are unaffected by the habitat island areas being in the units of hectares, and are thus unchanged. The supporting information Appendix S3 has been corrected and available online. The authors apologize for this error and any confusion this may cause.