Dawn Redwood

Scaffolding of living fossil

The dawn redwood is a deciduous conifer, just like the larch. The tree has long been known but only from the fossil record (70 to 5 million years ago).

In 1941, in an inaccessible area of China, a forester discovered a small population of unfamiliar trees: trees with thin branches, graceful foliage and a beautiful pyramid-shaped crown. Chinese dendrologists identified them as the supposedly extinct Metasequoia. In 1947 with the support from the Arnold Arboretum an expedition set out to collect seeds from which several botanical gardens in the Netherlands have grown material.

The dawn redwood grows fast and in China is now widely planted to supply timber for scaffolding used in many construction projects in the country.

Discovered in 1944 in the Shuishaba Valley

The genus Metasequoia was first described from fossil material. Shortly afterwards in Central China a new tree was discovered - a Metasequoia. It was a ‘living fossil’, similar to the more well-known Ginkgo biloba which is also found in China. In the wild the tree can reach about 35 m in height. On first sight this species looks like the bald cypress, Taxodium distichum, from North America. The dawn redwood differs in that its leaves are oppositely arranged whereas on the bald cypress they are offset.

Ecology and habitat

Small native populations of the dawn redwood occur on wet ground along rivers and in open woodland that flood regularly. Therefore it is similar to the bald cypress (Taxodium distichum) in its environmental requirements. The remaining populations are all of what remains of a, once extensive, riverine woodland, in which the dawn redwood was a component. In the Shuishaba Valley in China, where this species can still be found, a continental climate with warm summers and cold winters prevail.

Threat

When the species was discovered in1944, they grew in a forest comprising about 6000 large trees in the Shuishaba Valley. During the Chinese Revolution of 1949 this forest was felled. All that remains are small groups of trees here and there, lone witnesses to the original forest, enclosed by agriculture and villages. Although large individual trees are protected, the wild population is still under threat from increasing agriculture as its natural habitat is disappearing and the species cannot recover in the wild. The species can now be found worldwide - the result of botanic gardens and growers.