Alerce  (Fitzroya cupressoides)

This majestic giant conifer of the southern hemisphere inspires as much awe as its North American relative, the giant sequoia (Sequoiadendron giganteum) (5). Known locally as 'alerce', the species was declared a National Monument in Chile in 1976 (4). The reddish-brown trunk towers up to 60 metres tall, and the smooth bark often falls away in strips (2). The branches are relatively short and grow horizontally or downwards giving the alerce an overall conical appearance; large trees may sometimes be secured by buttress roots (2). The minute leaves are found in alternating whorls of 3 at the end of the branchlets (4), and male and females cones may be found either on the same, or on different, trees (5). Female cones are small and composed of 9 scales in alternative rings, the upper layer of which contains two-winged seeds (4); the tip of the woody cone ends in a resin-secreting structure that gives off a fragrant odour (5).

Found in southern Chile and Patagonia in Argentina (4). In Chile, alerce are known from the coastal mountain range, central depression and from the Andes (6).

These trees are found in temperate forests where there is a high seasonal rainfall, and where the soil is often poorly drained, peaty or sandy (2).

Alerce are extremely long-lived and may survive for many successive centuries; some known specimens are estimated to be over 3,600 years old (4). Valuable information on local climate can therefore be inferred by studying the tree rings of this species, a practice known as 'Dendrochronology' (5). Regeneration of this species is extremely intermittent and appears to depend on destructive events such as volcanic activity or fire. Although pure stands can exist, alerce are usually seen emerging above a much denser forest of broadleaved trees; waiting for the competition to be eliminated before regenerating (4).

The wood of the alcerce tree is highly prized as it is durable but lightweight and it has been used to make anything from furniture to ship masts (5). The resilience of the wood is evident from roofing tiles that are still in good condition despite being between 130 - 150 years old (2). Lumbering in Chile began towards the end of the 16th Century and continued right up to 1976, when the species was declared a National Monument, and the cutting of trees was therefore prohibited (7). The massive over-exploitation of the species caused population numbers to be decimated, and by the early 1900s a third of the Fitzroya forests had been lost (1). The naturally slow regeneration of this species means that any timber harvest is unsustainable and despite logging bans the species has not shown any sign of recovery (2). Today, the coastal populations appear to be declining although the direct cause is unclear; large tracts of dead, white stems have been found, although the time of death in many of these stands is unknown (7).

Logging of Fitzroya cupressoides is prohibited throughout the range of this magnificent tree, and international trade is banned by its listing on Appendix I of the Convention on International Trade in Endangered Species (CITES) (1). In collaboration with the Royal Botanic Gardens, Edinburgh, the University of Santiago is carrying out research into the conditions required for regeneration in order to assist propagation of these trees (8). The Global Trees Campaign is also involved in initiatives to restore and conserve remnant forests (6). This giant has a long history in Chile, and it is hoped that these efforts will help to restore the ancient forests to some of their former glory.

For more information on the Global Trees Campaign see:
http://www.globaltrees.org/

Authenticated (20/3/03) by Dr Aljos Farjon, Royal Botanic Gardens, Kew.
http://www.rbgkew.org.uk