The biological diversity of the United States is far richer than previously imagined, embracing more than 200,000 known species and more major ecological zones than any other country.
Indeed, scientists who compiled the inventory, collected over the past quarter-century, estimate that the eventual number of species found, ranging from microscopic marine jaw worms to 12-foot polar bears, could be two or three times as large.
The biological profile - the most complete analysis of the health and location of American wildlife - was drawn by a network of scientists organized by the Nature Conservancy, the nonprofit organization that buys land to protect natural habitat.
The bad news is that a third of the identified birds, fish, amphibians and plants are under threat of extinction. Habitat loss, competing alien species, pollution and disease are the prime culprits.
Most of the world's 1.75 million animals and plants are found in the tropics. But more than 10 percent of these species reside in the United States, which contains 12 of the 14 major biomes on Earth, from tundra and desert to prairie and rainforest.
America is the richest nation in the world in numbers of salamanders, crayfishes and freshwater turtles, snails and mussels. Nearly the same for pine-like trees. One river in Tennessee alone has more species of fish than in all of Europe. (Admittedly, two-thirds of the U.S.-cataloged species are insects and mushrooms, but that's true of most well-studied countries.)
The study is a field manual for protecting the nation's biological richness. It will give regulators a head start in locating at-risk species and devising ways to protect them, rather than waiting until these species totter at the brink of extinction. Governments and developers can use the information to plan around critical habitat.
This study can also steer Washington to do more of what the Nature Conservancy does - to come up with money needed for open-space conservation. The proposed Conservation and Reinvestment Act would direct about $1 billion a year (in off-shore oil royalties) to acquire and protect those valuable habitats of our biodiversity.