Uni-Bayreuth Uni-Augsburg Uni-Würzburg Elitenetzwerk Bayern



Primary succession on the subdesert scrub on La Palma recent lava flows

Francisco Cabrera Rodríguez
Universidad de La Laguna
Grupo de Investigación de Ecología y Biogeografía insular de la ULL


La Palma is the most volcanically active island of the Canaries, such activity is concentrated on the South of the island: Cumbre Vieja, a volcanic building of at least 123 ky; seven of the 15 historical volcanoes of the Canary Islands have occurred there. Subdesert scrub is a rather complex vegetation community, and primary studies on xeric ecosystems are scarce, surprisingly few studies about succession related with volcanism have being done in the Canary Islands. I am studying the vegetation succession with a chronosequence, The long and intense volcanic activity of Cumbre Vieja makes it a remarkable place to study a well defined set of chronosequences that differ also on orientation, aspect and elevation; furthermore,, the North to South orientation of Cumbre Vieja produces a windward/leeway effect in the East and West sides of it. The interaction among these features and lava flow age might be important to analyze how vegetation succession function in Cumbre Vieja.
Among the main objectives of the study are: to elucidate which variables are responsible or influence vegetation succession for the subdesert scrub in Cumbre Vieja. To analyze if species composition will depend on the degree of isolation from sources of potential colonists; also if age of the lava flows affect rate of vegetation development reducing compositional heterogeneity; and finally if vegetation structure converges towards that of neighbouring areas
I also want to study which succession model works for the primary succession of the subdesert scrub the classical model, in which initially discrete patches of competitive dominant colonists coalesce to form a homogeneous cover; or the patch dynamics model, in which renewal mechanisms such as disturbance create a shifting mosaic of patches at different stages; or the geoecological model, in which the vegetation gradually differentiates along edaphic gradients related to the underlying physical template.

Letzte Änderung 11.04.2011