The Valdivian temperate forests (NT0404) is an ecoregion on the west coast of southern South America, in Chile and Argentina.

Temperate rain forests comprise a relatively narrow Chilean coastal strip, between the Pacific Ocean to the west and the southern Andes Mountains to the east, from roughly 37° to 48° south latitude.

A few coastal enclaves of Valdivian forest grow in north-central Chile (such as Bosque de Fray Jorge National Park) as remains of the last glacial maximum.

The water vapour held by the westerlies condenses as they encounter the windward slope of the Chilean Coast Range and the Andes, creating orographic rainfall.

Together they are the second largest in the world, after the Pacific temperate rain forests of North America (which stretches from Alaska to northern California).

The Valdivian forests are a refuge for the Antarctic flora, and share many plant families with the temperate rainforests of New Zealand, Tasmania, and Australia.

Other notable species are the nalca or Chilean rhubarb (Gunnera tinctoria) and the ferns Lophosoria quadripinnata and Parablechnum cordatum.

Chile's national flower, the copihue (Lapageria rosea) is a pioneer species that grows in disturbed areas of the Valdivian rain forest.

The maximum plant species richness is found at latitudes 40 to 43° S.[3] There are four main types of forest ecosystems in the Valdivian ecoregion.

Tall coniferous pehuén monkey-puzzle trees (Araucaria araucana) grow at the southern edge of the deciduous forests, from the coast at Nahuelbuta National Park to the Andes.

Valdivian laurel-leaved forests, characterized by a variety of broadleaf evergreen trees, including Laureliopsis philippiana, Aextoxicon punctatum, Eucryphia cordifolia, Caldcluvia paniculata, and Weinmannia trichosperma, with an understory of Myrceugenia planipes, the arrayán (Luma apiculata) and other plants.

The alerce looks like a giant sequoia, and is a rival in longevity to the bristlecone pine, some with growth rings recording 3,625 years of local weather cycles.

[3] Its "Gondwanan" species are a legacy of the ancient supercontinent of Gondwana, a landmass formerly composed of South America, Africa, India, Antarctica and Australia.

The high degree of endemic species and monospecific genera is thought to be linked to the geographic isolation came into being as result of the uplift of the Andes.

These magnificent rainforests are endangered by extensive logging and their replacement by fast-growing pines and eucalyptus, which are more sought-after by the pulp and paper industry.

Gianni Lopez, Executive Director of CONAMA, Chile's national environmental agency remarked, "Ten years ago the existence of protected areas not owned by the government was unthinkable."