The Galapagos Islands Zones - Several vegetation zones may be defined according to the increase in elevation, the type and availability of water and variable soil characteristics:
Coastal zone: Found along the beaches, salt water lakes and rocky, low and uneven banks where vegetation is influenced by the presence of salt.
Predominant plants are small trees, bushes and grasses that tolerate salt. Predominating in coves and protected lakes, red mangrove (Rhizophora mangle), black mangrove (Avicennia germinans), white mangrove (Laguncularia racemosa), and button mangrove (Conocarpus erecta). Salt woodland (Cryptocarpus pyriformis) and Sesuvium spp are also common.
Arrid zone: Found in continuation of the coastal zone and is the most extensive area in the Galápagos.The most notable plants on them are cactus, represented by (Brachycereus nesioticus), the giant saguaro cactus (Jasminocereus thouasii) and four species of prickly pear (Opuntia spp).
There are also trees and bushes with small leaves, some with spines that cover the breaks in the lava: lignum vitae , Bursera graveolens, Chala Croton acouleri, Acacia Acacia spp; Matazarno Piscidia carhagenensis, Manzanillo Hippomane mancinella; a number of annual or perennial grasses that produce a green and abundant ground covering for a few weeks during the short growth period; and lichens in various colors.
Humid zone: Appears above the arid zone through a transitional strip in which elements from both zones are combined.The humidity in this zone is maintained during the dry period thanks to thick fogs and drizzle which accumulate throughout the night and persist during the day.
Predominant in this area is the pawpaw tree (Scalesis spp, up to 20 meters tall), together with the guava tree (Psidium galapageium)and the pega pega (Pisoma floribunda).The trailing vegetation is made up of bushes, lianas, bromeliads and numerous species of ferns, orchids, mosses, liverwort and lichens which grown on trunks, branches, stems and even on leaves of some species.
Miconia zone: Tall trees are replaced by low and dense bushes; cacaotillo (Miconia robinsoniana) which reaches heights of two to four meters.This zone is most extensively developed on Santa Cruz Island.
Due to the dense grown of the liverworts and lichens vegetation is produced that is a shade of brown a color that is accentuated more in the dry season.This zone has been almost entirely changed by people because of farming and grazing activities and only small areas remain of this type of vegetation in its natural state.
Zone of ferns, gamneous, cyperaceuos: Covers the area of the peaks of the largest islands where the humidity is retained in temporary lakes by sphagneous mosses. Thin leaves and other adaptations of the plants serve to reduce the loss of water.
Most of the floral life includes cyperaceous, gramneous and ferns that are perennial, mixed with low bushes.
The endemic arborescent ferns (Cyanthee weartherbyane) are on channeled places formed by lava and in other small cavities associated with rushes, gramneous, mosses, sphanagneous and orchids.