ABSTRACT
The effect of human activities on the vegetation mantle of the earth historically has tended to be especially severe on island ecosystems. The Canary Islands, which originally supported substantial stands of both coniferous and broadleaf evergreen forests, offer an instructive, but little-known example of the continuing interaction between man and environment. Mature, straight-boled trees normally reach a height of 20 to 30 meters. Much influenced by human activities, stand densities vary greatly, but a light, open forest with sparse under-growth is most characteristic, especially on drier sites. There is uncertainty as to when the first Gaunche peoples reached the Canary Islands from North Africa with goats, sheep, and pigs, but their arrival was definitely well before the time of Christ. Water is overriding problem in the Canary Islands today. "Mined" for more than a century from pervious lenses in the complex volcanic rocks that make up the islands and used mostly for irrigation, water is in perilously short supply.
