NW USA

The NW North America Threatened Conifer Region extends from British Columbia in Canada down the Pacific coast as far south as San Francisco and with a southern inland limit of Fresno. The western slopes of the Rocky Mountains form the eastern limit. It encompasses major mountain ranges including the Cascades, Sierra Nevada and the Transverse Ranges in southern California. It also includes the Klamath-Siskiyou region which bridges the coastal mountain ranges of California and Oregon and the Pacific Coast Ranges. The Region is one of the most diverse areas in the world for temperate conifers and is especially famous for having some of the most enormous conifers in the world, namely Sequoia sempervirens and Sequoiadendron giganteum. Much of the area is included in the Biodiversity Hotspot of the Californian Floristic Province and is characterised by cool, wet  winters and hot, dry summers with many conifers in the coastal forests reliant on persistent summer fog. Threats in this Region include fragmentation of forests and reductions in population sizes due to historic logging and forestry management practices that favour particular species, urbanisation, grazing and the introduction of exotic pests and diseases. Many years of fire suppression and other management practices have caused high-intensity fires which has led to the loss of large areas of conifer forests.

Taxa in the category - NW USA:

 world map

blob indicating NW USA on map

Cupressus bakeri Jepson

Known from nine sites in northern California and south Oregon where fire and the introduction of pests and diseases are major threats Read full species entry >

 world map

blob indicating NW USA on map

Cupressus sargentii Jepson

Endemic to the coastal mountain ranges in California, USA. Even though it has a relatively large range, it is threatened by fire Read full species entry >

 world map

blob indicating NW USA on map

Picea breweriana S.Watson

Restricted to the Klamath Ranges of northwestern California and southwestern Oregon where the main threat is from fire and climate change. Read full species entry >

 world map

blob indicating NW USA on map

Pinus albicaulis Engelm.

Native to Western USA and Canada where historically large areas of forests were lost to the mining industry; today it is threatened by wildfire, White Pine Blister Rust and Mountain Pine Beetle Read full species entry >

 world map

blob indicating NW USA on map

Sequoia sempervirens (D. Don) Endl.

Endemic to the Pacific coast of the USA where historical logging has had significant effect of the population; present-day threats include selective logging and urbansiation Read full species entry >

 world map

blob indicating NW USA on map

Sequoiadendron giganteum (Lindl.) J.Buchholz

Restricted to California, USA where the groves have declined due to past logging. Today the main threats relate to fire management regimes, increases in the severity and frequency of fires and changes in precipitation patterns associated with drought. Read full species entry >

 world map

blob indicating NW USA on map

Torreya californica Torr.

Endemic to California, USA where historically it was heavily logged and today it forms small, localised subpopulations Read full species entry >