Eastern Pacific High Sea

The Chala coastal desert runs from the Pacific shore to elevations of about 500 metres. Near the ocean, fog and mist often replace rainfall. Their moisture supports lomas ecosystems on the first western slopes, usually between 150 and 600 metres and in places up to about 1,000 metres. The belt is discontinuous and lies amid nearly rainless terrain, becoming drier toward the south. Average temperatures remain moderate overall because of the ocean influence, although daily extremes can still reach 33°C or fall to 8°C.

The seaward waters adjoin this thin zone where clouds, sterile-looking slopes and vegetation meet. Anchovy, sea lions and several seabird species belong to the coastal fauna, while rivers introduce trees and grasses adapted to damp ground. Among them are carob, palo verde, salt-tolerant grama grass, mangrove, giant reed and Canebrava. On the lomas, the Peruvian daffodil, wild tomato, Peruvian papaya and divi-divi provide traces of the ecological diversity sustained by water that arrives without steady rain. Farther north, where the central and southern coastal desert gives way to Piura and Tumbes, equatorial dry forests support thorny savanna trees. These conditions place the coastline within the South American Coastal Deserts bioregion and make offshore productivity and narrow river valleys unusually significant.