Vegetation

Abstract

In the island, seven vegetation types related to altitude and terrain forms are recognized. The more protected and lower mountain slopes and valleys show the development of Nothofagus betuloides and Drimys winteri forest characteristics of the true Subantarctic Evergreen Forest. In those sites constantly exposed to continuously strong wind conditions, the main vegetation is the Magellanic Moorland Formation, a mosaic of interfingered and superimposed subunits that may cover a rather small area forming blanket-like patches. The Scrub Formation occurs on mountain slopes exposed to the prevailing southwesterly and westerly winds where trees of Nothofagus antarctica and shrubs grow low and tortuous. Above approximately 450 m the so-called Alpine Formation occurs with sparse vegetation cover, and often includes dwarfed forms of Nothofagus antarctica and Empetrum rubrum. Soil conditions also influence the vegetation that characterizes the island. For example, the cold and damp climate favors peat development mainly at low and intermediate elevations. However, in spite of the constant soil humidity, the topography influences drainage patterns and this is reflected by the composition of the vegetation. Littoral and Maritime Tussock Formations develop along the stony and rocky coastal areas, small peats and soils above the high tide line and in rock crevices at the intertidal zone.