The New York Times
April 9, 1998
Plant Survey Reveals Many Species Threatened With Extinction
By WILLIAM K. STEVENS
At least one of every eight plant species in the world -- and nearly one of three in the United States -- is under threat of extinction, according to the first comprehensive worldwide assessment of plant endangerment.
The assessment, which required more than 20 years of work by botanists and conservationists around the globe, added nearly 34,000 plant species to the World Conservation Union's growing Red List of imperiled organisms. The survey was made public Wednesday in Washington.
Plants in Trouble
The United States leads the world in the number of plant species identified as threatened by extinction. Here are the countries with the largest number of threatened species, along with the percentage of the nationís plants that are in jeopardy.
Imperiled Species Percent of Total Species United States 4,669 29.0 % Australia 2,245 14.4 South Africa 2,215 9.5 Turkey 1,876 21.7 Mexico 1,593 6.1 Brazil 1,358 2.4 Panama 1,302 13.1 India 1,236 7.7 Spain 985 19.5 Peru 906 5.0 Cuba 888 13.6 Ecuador 824 4.3 Jamaica 744 22.5 Colombia 712 1.4 Japan 707 12.7
Source: The World Conservation Union
Among the plants most at risk, the survey found, are 14 percent of rose species, 32 percent of lilies, 32 percent of irises, 14 percent of cherry species and 29 percent of palms. Coniferous trees as a group, and many species found in island nations, were also judged especially vulnerable.
While endangered mammals and birds have commanded more public attention, it is plants, scientists say, that are more fundamental to nature's functioning. They undergird most of the rest of life, including human life, by converting sunlight into food. They provide the raw material for many medicines and the genetic stock from which agricultural strains of plants are developed. And they constitute the very warp and woof of the natural landscape, the framework within which everything else happens.
The census of imperiled plants should be taken not as an exact measure of the situation, leaders of the survey said, but rather as a first, rough approximation.
And some acknowledged that the majority of species were "secure and widespread," in the words of Dr. Bruce Stein, a botanist who is a senior scientist with the Nature Conservancy, one of nine scientific and conservation organizations that participated in drawing up the list. Furthermore, Stein said, some plants were placed on the list simply because they are rare, not because their numbers are declining or their habitat is threatened.
Nevertheless, of the world's 270,000 known species of plants, the 12.5 percent found to be at risk is a huge proportion, said David Brackett of Ottawa, chairman of the World Conservation Union's Species Survival Commission. Moreover, he said, the figure is probably an underestimate, since data from most places in the world -- including some species-rich tropical nations where the countryside is being rapidly cleared -- are fragmentary.
The list of imperiled plants fills more than 750 pages of a large red-bound book. Nine of every ten plants on the list are found in only one country, making them especially vulnerable to national or local economic and social conditions. Many species are found only on a few islands, and countries like Mauritius, the Seychelles and Jamaica consequently have disproportionately high numbers of threatened plants.
Scientists generally cite two main reasons why plants become endangered: destruction of large swatches of wild countryside by agriculture, logging or development, and invasions of plants from one part of the world that run riot and crowd out native species in another part.
The new listing of endangered plants is one more piece of evidence that "a whole chunk of creation is at risk," said Dr. Stuart Pimm, an ecologist at the University of Tennessee, who was not involved in producing Wednesday's report. While 1 plant in 8 might not seem like much, he said, "that's what's threatened now, as a consequence of what we've done so far; but all the evidence is that the destruction is continuing at an accelerating pace."
The United States' situation looks comparatively grim, said Stein, because plants are probably better surveyed here than elsewhere. With 4,669 species judged to be threatened to one degree or another, the United States ranked first, by far, among the nations of the world in total number of plants at risk. That is 29 percent of the country's 16,108 plant species.
"I don't believe the U.S. is worse off than other countries," said Stein. "If anything, I think the U.S. has taken a more active interest in plant conservation."
Stein's group, the Nature Conservancy, maintains what is widely regarded as one of North America's most comprehensive databases on endangered plants. Other major American participants in drawing up the Red List were the New York Botanical Garden and the Smithsonian Institution's National Museum of Natural History.
The conservation union, also called the International Union for the Conservation of Nature, or IUCN, is based in Gland, Switzerland. Many governments and scientific organizations are among its members. Since 1960, it has been maintaining and adding to its Red List of threatened species. The list has no official effect but is widely regarded as an influential guide for conservation policy makers.
Two years ago, the union placed nearly a quarter of all known mammal species and 11 percent of birds on the list. It also added a number of marine species for the first time.
The Red List establishes five categories of organisms: species not seen in the wild in 50 years and presumed extinct; species suspected of having recently become extinct; endangered species, those likely to become extinct if the causes of endangerment continue; vulnerable species, those likely to become endangered if the causes continue; and rare species, those with small worldwide populations not yet endangered or vulnerable. Of the total number of plants on the Red List, 43 percent are classified as rare, 24 percent as vulnerable and 20 percent as endangered.
These categories are different from those established under the United States' Endangered Species Act, and cannot be compared with them. The American categories, in descending order of seriousness, are called endangered and threatened.
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