During the years 1964 and 1965 an ecological study was realized on the littoral region of the coast of Valparaiso Bay, Chile in order to analyze the vertical distribution of the organisms. Observations were realized on the lowest levels of the terrestrial zone to depths of 20 meters below mean tide level.
The ecological model we have used allowed us to determine various zones and to represent patterns within different habitats.
The fundamental results indicate that:
- The littoral region is the convergence of two very different systems, TERRESTRIAL AND MARINE.
- The terrestrial system consists of 1) A TERRESTRIAL ZONE, the lower level of which is characterized by plants of the genera Nolana, Carpobrotus and Oxalis. 2) GEOLITTORAL ZONE which is characterized by the lichen genera Caloplaca, Verrucaria, Lichina, and the isopod genus Ligia.
- The marine system consists of 1) A HYDROLITTORAL ZONE which is characterized by the principal genera Porphyra, Ulva, Centroceras, Gelidium, Dendrymenia, Perumytilus, Chthamalus, Littorina, etc. 2) A MARINE ZONE characterized by the principal genera Glossophora, Corallina, Lithothamnion, Plocamium, Lessonia, etc.
- There is a transitional area between two adjacent ecological zones.
In the vicinity of Montemar, zonational studies were complemented with observations on the horizontal distribution of species in various habitats as well as on the influence of several environmental factors. It has been determined that the most noticeable biological differences are caused by the following fundamental factors: wave effect, orientation, inclination and nature of substratum, illumination and grade of humidity. The associations existing in the explored area have been analyzed in relation to the most favorable environmental condition for their development.
Finally, a comparative analysis between this locality and other localities in Chile and the world is given.
