Cambios globales del clima y de los hábitats terrestres

Abstract

This paper offers a global synthesis of the evolution of climate and terrestrial habitats, stressing the environmental aspects which have had greatest repercussions on the present-day biogeographical configuration of the NW Iberian Peninsula and its human population. Although the environmental history of the territory can be dated to the oldest periods in the history of the Earth, the factors, which have determined and shaped the biocenosis in which primitive man lived, can be related to the cyclical fluctuations in the succession of glacial and interglacial phases that took place from the end of the Tertiary. This cyclical succession brought about the extinction of many of the thermophiles species which had been in expansion from the end of the Mesozoic or resulted in their progressive confinement to the different areas of refuge in the South of Europe, especially in the Iberian Peninsula, Italy and the Balkan Peninsula. They spread from these refuge areas in interglacial periods towards mores septentrional areas or areas situated at higher altitudes. The succession of climatic and environmental fluctuations, which marked the end of the Cenozoic, conditioned, therefore, the area of distribution of the flora and fauna of the whole European continent, and equally affected the expansion of the different human groups and their cultural evolution.