Fig. 4.

Gas exchange data for M. tessellata (dark green) and P. crispa (light green) measured at +20 ºC in hydrated samples in the laboratory of the BAE JCI. (A) Light curve of net CO₂ assimilation expressed on a thallus area basis. (B), (C), (D) and (E) depict maximum net assimilation A_n (A_sat), dark respiration (R_d), irradiance at which 90 % of A_sat is achieved (I_sat90) and light compensation point (I_com), respectively, calculated by Michaelis–Menten curve fitting. Data are mean ± s.e. (n = 4 or 5). Asterisks denote significantly different values (P < 0.05).