Chorology

CHOROLOGY. - The term c. (from χάρα, land and λάγος, discourse) designates the study of the geographical distribution of living beings: thus a zoogeography for animals and a phytogeography for plants are distinguished. Such distribution and diffusion of faunas and floras depends in the first place on present-day or ecological factors, that is, on the present existence of adequate climatic and environmental conditions; it depends, however, also on historical or geographical factors, that is, on the geological and climatic vicissitudes undergone by the earth's crust throughout its history. Thus, separations of continents and islands, which occurred in given geological eras, can account for the absence or presence of particular zoological groups, according to the epoch in which these appeared on earth; and changes in climatic conditions can explain the reductions or fragmentations of the areas of diffusion in many species, which in the past had a more extensive geographical distribution. The action of man, too, can considerably alter the distribution of faunas and floras.

Enrico Vannini