Table 1 Effect of warming and limpets on community composition and succession.

PERMANOVA was used to determine how treatments affected community composition at the end of the 16-month-long experiment (28 August 2012), and permutational analysis of multivariate dispersions (PERMDISP) was used to determine how variable composition was within treatments. Similar analyses were conducted to determine whether community succession differed between treatments. Pairwise comparisons indicate whether treatments were significantly different (★) or not (ns). Further details are provided in tables S3 and S4. Amb, ambient; W, warming; L, limpets.

SourcedfFPEffect sizePairwise comparisons
After 16 months
Community composition (PERMANOVA)Amb (−)Amb (+)Warm (−)Warm (+)
W1,2813.56<0.00129.04%Amb (−)
L1,288.79<0.00122.86%Amb (+)ns
W × L1,282.750.03815.33%Warm (−)
Variability in community composition (PERMDISP)Amb (−)Amb (+)Warm (−)Warm (+)
W × L3,286.500.004Amb (−)nsns
Amb (+)ns
Warm (−)ns
Successional trajectory
Community succession (PERMANOVA)Amb (−)Amb (+)Warm (−)Warm (+)
W1,287.08<0.00125.72%Amb (−)ns
L1,283.210.00215.52%Amb (+)
W × L1,282.340.02317.04%Warm (−)ns
Variability in succession (PERMDISP)Amb (−)Amb (+)Warm (−)Warm (+)
W × L3,286.430.006Amb (−)nsnsns
Amb (+)nsns
Warm (−)ns