Year: 1964
Type: dissertation
Abstract: The Sierra de Tuxtia, a small, isolated volcanic m o m t a i n area near the Gulf coast of southern Veracruz, Mexico, affords excellent conditions for biogeographical investigations.The present study de scribes the manner in which physical and human factors have influenced native vegetation, nontransient avifauna and larger forest mammals in this tropical region.Physical factors considered are geology, land configuration, climate, drainage and soils; human factors examined include population, settlement and forms of land use.Following the Sierra's permanent emergence from nairine inunda tion in the Tertiary, volcanism and erosion gradually transformed the land surface into its present configuration of high-walled craters, steep cones, ridges, valleys and undulating uplands.Most Sierra soils have been derived from-basic volcanic materials, and some were formed from sedimentary rocks.The soils' variable depth and compo-' sition reflect this complex surface configuration and cause a marked variability in vegetation structure.High annual rainfall and generalljT warm temperatures interact with soils to support a rain forest subformation chiefly on the Gulf side of 'the range.Poorer soils and lower precipitation on southern slopes support forests of gum, pine, oak and semideciduous tropical broadleaf trees.The Gulf of Mexico is a major source of moisture affecting vegetation, and orographic rainfall, especially during northers and easterly waves, is a significant influence.The aspect of a forested region in a tropical environment was largely maintained through the Sierra's geological history.
Author: Andrle, Robert F
Institution: Louisiana State University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Life on land
Open Access status: gold
OpenAlex ID: W3020445537