ABSTRACT
The coevolution between flowering plants and animals is the principal mechanism by which Angiosperms conquered most of the earth’s surface, overtaking Gymnosperms or Cryptogams. The taiga are large evergreen conifer forests of the boreal regions, undergoing a cold season of eight months. Mangrove forests are a particular form of tropical rainforest that colonize the intertropical sea coasts in which the brackish water is sufficiently warm. It is a type of vegetation confined to regions exposed to tides and has an optimal development along estuaries. The juxtaposition of different types of vegetation on a single territory leads to an increase in the overall rate of species diversity, the rates of each environment being cumulative. The vegetation of subalpine and alpine stages is made up of discontinuous bushy formations, adapted to abrupt daily thermal contrasts. The richness of the vegetation of tropical mountain forests is remarkable. The diversity is wide because of the multitude of environments generated by the altitudinal stages.
