GEOGRAPHY:

San Cristobal is comprised of two coalesced volcanoes.¹ The southern volcano is approximately 2.5 million years old, covered with slow-dripping lava.¹ The northern volcano is much more recent, having lava flows only a few centuries old.¹ The main island is approximately 558 square kilometers in area, having only one significant island: Isla Lobos.² A prominent pyroclastic cone (a volcano that mixed with sea water) called Kicker Rock is a popular offshore destination.¹

On San Cristobal there are several very distinct growth zones.  The lowest, the Arid Zone, is desertlike and home to the largest number of species on the island, including many types of deciduous tree and other plants adapted to drought, like cacti.  The Transition Zone, the next up, is, as you might expect, more difficult to characterize.  Following the Transition Zone is the Scalesia Zone, a cloudy forest filled with the endemic Scalesia tree and other evergreens.  Next is the Brown Zone, another transition zone, full of trees draped with lichens, mosses and ferns.  The Miconia Zone, present only on San Cristobal and to a lesser extent on Santa Cruz, is the next area, densely covered in Miconia shrubs.  The last zone, the Pampa Zone, occurs only on a few islands.  San Cristobal's Pampa zone is above the tree line for that part of the world at about 4000 feet elevation.  It is very wet and home to grasses and sedges.^3,4,5