. The algae. Algae. SUMMARY O2 UPTAKE. Juvenile Hormosira 100 Adult Hormosira 0 12 4 8 HOURS AFTER IMMERSION 16 Fig. 210 Respiration rate of juvenile and adult Hormosira hanksii and Ecklonia radiata after desiccation and re-immersion. Note that the adult Hormosira and Ecklonia return to the control value (non- dehydrated plants) but the juvenile Hormosira does not. (After Bergquist.) appeared as a result of the habitat they occupy. In the case of Hor- mosira the rate of water loss is correlated with bladder size (see p. 213)5 the larger the bladder the slower the rate of water loss (Fig. 209A)
. The algae. Algae. SUMMARY O2 UPTAKE. Juvenile Hormosira 100 Adult Hormosira 0 12 4 8 HOURS AFTER IMMERSION 16 Fig. 210 Respiration rate of juvenile and adult Hormosira hanksii and Ecklonia radiata after desiccation and re-immersion. Note that the adult Hormosira and Ecklonia return to the control value (non- dehydrated plants) but the juvenile Hormosira does not. (After Bergquist.) appeared as a result of the habitat they occupy. In the case of Hor- mosira the rate of water loss is correlated with bladder size (see p. 213)5 the larger the bladder the slower the rate of water loss (Fig. 209A). Plants with large bladders occur at the higher levels on the shore so that morphology provides protection in this species. A further feature that has received very littie attention is the effect of desiccation upon the major metaboHc processes, respiration and photosynthesis. A recent study upon Hormosira (Bergquist, 1957) has shown that the effects may be quite different in the sporehng as compared with the adult (Fig. 210). This may be of profound significance and further work is clearly required. It appears that the respiration rate decreases with increasing desiccation (Bergquist, 1957). For comparison with the water relations of fucoids, reference may be made to the work of Anand (1937) on the marine algae of the Dover cliffs. Here two important belts are dominated, the one by Enteromorpha and the other by Chrysophyceae. Anand found that the Enteromorpha mat lost 25 per cent of its moisture in the first 3 hours of exposure, whilst the Chrysophyceae belt lost 8-4 per cent. The relative loss by evaporation from these two belts is shown in Fig. 21 lA, whilst the corresponding loss due to drainage is shown in Fig. 21IB. The measurements were obtained by the 390. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original wo
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Keywords: ., bo, bookcentury1900, bookcollectionbiodiversity, booksubjectalgae
