Figures & data
Fig. 1. Map of the northern Iberian Peninsula showing the 20 intertidal sites sampled between Buelna (1) and Arnao (20). Site 11 is Aramar beach.
Fig. 2. North coast of Spain: kelp distribution maps in the 1980s and 2000s. Dense populations (dark) and small patches or isolated individuals (grey) are indicated.
Fig. 3. Annual pattern of biomass of Saccorhiza polyschides at the end of the 1970s (mean values ± S.D.).
Fig. 4. Long-term changes in the standing crop (a), density (b), thallus length (c) and density of fertile specimens (d) of Saccorhiza polyschides (mean values ± S.D. in each case).
Fig. 5. Saccorhiza polyschides: survivorship curves for the main cohort of 1977 and the only cohort of 2005 growing at three low intertidal levels: 0.20 m above LAT (dark circles), 0.40 m above LAT (open circles) and 0.70 m above LAT (dark inverted triangles).
Table 1. Critical temperatures for different phases and processes of the life history of Saccorhiza polyschides, based on data of Kain (Citation1969) and Norton (Citation1977). The months when the process takes place, according to Fernández (Citation1980), are given in parentheses.
Fig. 6. (a) Mean annual sea surface temperature (SST) and (b) number of consecutive days with SST > 20°C recorded by in situ loggers (open circles) and satellite (dark circles) on the north coast of Spain at Aramar beach (43° 36′ N, 5° 46′ W9) and 43° 37′N, 5° 38′W, respectively.
Fig. 7. Saccorhiza polyschides: relationship between the density of algae with developed bulbs (>3 rows of haptera) and the number of consecutive days with SST > 20°C.
