|Scientific Name:||Commidendrum spurium (G.Forst.) DC.|
Aster gummiferus Hook.f. pro parte
Conyza cuneifolia Raeusch. non Lam.
Solidago spuria G.Forst.
|Red List Category & Criteria:||Critically Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C1+2a(i,ii); D ver 3.1|
|Assessor(s):||Lambdon, P.W. & Ellick, S.|
As there is only one extant patch of seven plants, the False Gumwood (Commidendrum spurium
|Previously published Red List assessments:|
The False Gumwood is restricted to the western Central Ridge of St Helena, South Atlantic Ocean.
Native:Saint Helena, Ascension and Tristan da Cunha (Saint Helena (main island))
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||In 1983, the world population numbered 10 individuals at three sites. At the time of the previous Red List assessment (Cairns-Wicks 2003), this had declined to eight plants at two sites, and since then, it has again declined to six individuals. The single tree on a cliff at Sheep Pound (near Cole’s Rock) died in 2013, leaving the remaining population confined to Mt Vesey. The surviving plants may also be displaying signs of ageing.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
Over the last century there have never been more than a few known individuals in existence and many details of the species’ ecology therefore remain unknown. Of the four extant species in the endemic genus Commidendrum, the False Gumwood appears to have had the most montane distribution, with all recorded wild plants occurring between 650 and 750 m altitude. It is not entirely clear what the associated vegetation would have looked like. The elevation range lies somewhere between a belt thought to have been dominated by upland gumwood forest and the true cloud forest zone nearer the summits, dominated by cabbage trees (Asteraceae spp.) and Tree Ferns (Dicksonia arborescens L’Hér). However, the original habitat has been entirely destroyed, largely as a result of the large-scale replacement of native upland forest with plantations of New Zealand Flax (Phormium tenax J.R.Forst. & G.Forst.) in the late 19th and early 20th Centuries.
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||100|
|Movement patterns:||Not a Migrant|
|Use and Trade:||Would have been used as firewood and for timber by early settlers.|
The main cause of decline in the population seems to have been severe habitat loss. Following the establishment of a permanent colony on St Helena in 1658, human exploitation has resulted in heavy reductions to the island's original upland vegetation. Initial impacts arose from conversion of land to pasture, and felling of native woody species for firewood. The establishment of extensive New Zealand Flax plantations along the least productive, steep slopes of the Central Ridge probably cause further, heavy tolls in the late 19th and early 20th Centuries. In subsequent decades, this has been further compounded by smaller-scale habitat deterioration as a result of invasion by non-native shrubs, herbs and grasses. Typically for Asteraceae species, the fruits are small, wind-blown achenes with a pappus. Grass swards provide intense competition for small germinating seedlings and form a barrier which prevent the achenes from coming into contact with the ground.
The Mt Vesey site has recently been designated as part of the Central Peaks National Park. Routine weed clearance is conducted twice a year by staff of the island’s Environmental Conservation Section (St Helena Government), and seed collections have been made from all extant individuals. This has been banked on-island and also at Kew's Millennium Seed Bank in the UK. Unfortunately, due to the challenging location, only very small quantities of seed were obtained from the Sheep Pound tree before it died, but an additional collection made from an additional tree which grew at Oaklands in the 1990s has recently been repatriated to St Helena from the Royal Botanic Gardens, Edinburgh.
|Citation:||Lambdon, P.W. & Ellick, S. 2016. Commidendrum spurium. The IUCN Red List of Threatened Species 2016: e.T37588A67370705.Downloaded on 18 December 2017.|
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