Interactions bryozoaires-sédiment dans les environnements actuels et fossiles

Résumé En Fr

Bryozoan-sediment interactions in recent and fossil environments. Among the various ecological factors which influence the growth of bryozoans, substratum and rate of deposition are especially important. They interact with hydrodynamism in determining the distribution of species and zoarial forms, or colony growth forms. Fossil and Recent bryozoan assemblages are thus narrowly dependent on the sedimentary conditions occurring in a given environment. In turn, bryozoans contribute to sediment formation. They may constitute reefs of various sizes, alone or with other organisms, but usually only attach themselves to skeletons of frame-builders such as corals or calcareous algae. Bryozoan colonies may also develop in numerous layers on different substrates and form concretions and nodules. More often, bryozoan remains accumulate on sea floors together with other bioclasts.

Parmi les facteurs écologiques qui conditionnent la vie des bryozoaires, la nature du substrat et le taux de sédimentation sont particulièrement importants. Les formes zoariales, ou formes de croissance des colonies, ainsi que le plus ou moins grand développement des assemblages à bryozoaires en dépendent étroitement. Les bryozoaires agissent à leur tour sur le sédiment en intervenant à titre principal ou accessoire dans divers types de constructions, de concrétions et d'accumulations.