EXTINCTION looms for some of the most ancient trees on Earth. A quarter of
the world鈥檚 conifer species are under threat, many of them survivors from the
age of the dinosaurs. And more than one in ten species is likely to disappear in
the next few decades, the World Conservation Union (IUCN) warned this week
in its Action Plan for Conifers.
Only three specimens remain of the world鈥檚 rarest conifer, the Chinese
species Abies beshanzuensis. And another Chinese species, Thuja
sutchuenensis, has disappeared from the wild altogether, surviving only in
cultivation. Logging, mining, wildfires, agricultural and urban
development鈥攅ven ozone pollution鈥攁re all taking their toll.
The greatest diversity of conifers is at low latitudes and in the tropics;
forests in the north have billions of trees but few species. 鈥淧eople perceive
conifers as very common because they think of vast northern forests of pines and
firs. They don鈥檛 realise the great majority are more isolated鈥攇rowing on
the fringes of the Pacific, on tropical mountaintops or islands or at the tips
of the southern continents,鈥� says Christopher Page, one of the plan鈥檚 authors.
鈥淚t鈥檚 these we are especially worried about.鈥�
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Many of these species are relics from the Mesozoic era that began 225 million
years ago. Once flowering plants arrived, the vast conifer forests disappeared.
Many species died out, others retreated into smaller refuges, often in lands
with harsh climates or poor, sometimes toxic soils. 鈥淭hese are areas where whole
genera and families are threatened with rapid extinction. No animal group is in
quite such jeopardy,鈥� says Page.
Many ancient species are sought after for their dense, rot-resistant timber.
鈥淭he most ancient conifers are also the most slow growing,鈥� says Page. 鈥淔or
some, recovery could take a thousand years.鈥�
The new action plan shortlists 42 conifers for urgent attention and nine
鈥渉otspots鈥� where conservation will protect at least eight species. It suggests
areas that should be protected against logging, mining and fire, and regions
where the conifers鈥� shrinking habitat must be restored. As an insurance policy,
says Page, it is vital to store seed in seedbanks and plant the rarest conifers
in safe havens such as botanic gardens.
The Pacific island of New Caledonia is one of the top priorities. The island
has 43 unique conifer species. Strip mining of the metal-rich soils is a serious
problem. Ironically, these conifers have hung on this long because they have
adapted to growing in metal-rich soils鈥攖he ones now sought after by
miners.
Conifers could also prove to be a valuable medicine chest. One species, the
Pacific yew (Taxus brevifolia), has already provided the anticancer
drug Taxol. 鈥淭hese ancient plants have all sorts of properties that are very
different from modern plants,鈥� says Page. 鈥淲ho knows what else we might find?鈥�