Resistance of rocky intertidal communities to oceanic climate fluctuations

Table 3. Analysis results for the focal functional groups with the highest average annual dissimilarity in the a) high, b) mid and c) low zone. Multiple regression models tested the effects of mean Pacific Decadal Oscillation index (mean PDO), mean North Pacific Gyre Oscillation index (mean NPGO), mean El Niño Southern Oscillation index (mean ENSO), mean and standard deviation of the Biologically Effective Upwelling Transport Index (mean and SD BEUTI, respectively), mean daily sea surface temperature (Mean SST), mean daily maximum air temperature (Max Air Temp), and years since the sea star wasting disease epidemic (Yr Since SSWD) Only those model terms that met the significance threshold of P < 0.00625 (Bonferroni correction) are listed, and these were subsequently tested for bivariate correlations between the climate term and the taxon abundance. Bold statistics indicate bivariate adjusted R2 of > 0.1. a) High zone Model Response Average Annual Dissimilarity Model Marginal R2 Sig. Terms (p < 0.0065) Bivariate Correlation Herbivorous snails 8.40 0.34 Mean PDO -0.057 Mean NPGO +0.157 ENSO -0.054 SD BEUTI -0.001 Max Air Temp -0.048 Mean SST < -0.001 Yr Since SSWD -0.239 Limpets 6.45 0.42 Mean PDO -0.038 Mean NPGO +0.122 ENSO -0.037 BEUTI +0.044 SD BEUTI +0.164 Max Air Temp +0.059 Mean SST -0.029 Yr Since SSWD -0.151 Balanus glandula 4.55 0.05 None sig. Fucoid algae 4.46 0.51 SD BEUTI -0.077 Chthamalus dalli 3.12 0.12 None sig. Mussels 3.10 0.32 PDO <+0.001 Bare Space 2.74 0.13 None sig. Mastocarpus papillatus 2.35 0.18 None sig.

b) Mid zone Model Response Average Annual Dissimilarity Model Marginal R2 Sig. Terms (p < 0.0065) Bivariate Correlation Limpets 7.98 0.40 Mean PDO -0.222 Mean NPGO +0.107 Mean ENSO -0.025 SD BEUTI +0.109 Max Air Temp -0.005 Mean SST -0.065 Yr Since SSWD -0.131 Predatory Snails 5.13 0.39 Mean NPGO +0.030 Mean ENSO <+0.001 SD BEUTI -0.034 Max Air Temp -0.117 Yr Since SSWD -0.012 Bare Space 4.74 0.32 None sig. Large barnacles 4.37 0.33 None sig. Gooseneck barnacles 3.63 0.27 Mean NPGO -0.010 Yr Since SSWD -0.001 Mussels 2.71 0.22 Yr Since SSWD +0.136 Endocladia muricata 2.30 0.63 Max Air Temp +0.255 Balanus glandula 2.18 0.60 None sig. (Continued) PLOS ONE Resistance of rocky intertidal communities PLOS ONE | https://doi.org/10.1371/journal.pone.0297697 May 29, 2024 18 / 34