Banks of algal microscopic forms: hypotheses on their functioning and comparisons with seed banks

Abstract

It has been proposed that a 'bank of microscopic forms' functions as a survival mechanism for benthc macroalgae, m some ways analogous to the 'seed bank' of terrestrial plants. Four aspects related to this hypothesis are examined here, namely (1) origin and morphology of the structures forming banks, (2) their specific compositions, (3) environmental conditions that allow their survival in a state of suspended growth, and conditions that trigger reinitiation of growth; and (4) losses from the banks by diverse causes Although the structures at which growth suspension occurs are of very different morphologies, and probably are also different in their capacities of temporal displacement, both types of banks are regulated by similar environmental factors and subjected to similar types of constraints. Some important differences between the 2 banks are likely to stem from the lesser longevity of the algal microscopic stages, which would limit the duration of banks of microscopic forms