476 Tree Species Found in Patch of Rain Forest

Ecologists have found that a small patch of Brazilian rain forest contains 476 tree species, more than any spot of similar size ever studied.

All 476 species were confined to a 2.5-acre plot, a Brazilian ecologist reported during the Atlantic Forest Ecological Corridors Workshop, a meeting held recently in the Brazilian state of Bahia.

The study area, about 300 miles northeast of Rio de Janeiro, is part of a rain forest ecosystem that is frequently cited as one of the world’s most endangered.

“It just reemphasizes how important these threatened hot-spot areas are,” said Russell Mittermeier, who is president of Conservation International and attended the mid-October meeting.

The study was done in the Atlantic coastal forest, an area of eastern Brazil that has been decimated since the Portuguese settled it 500 years ago. Ecologists estimate that about 5% of the original forest remains.

Conducted by Luciana Dias Thomaz of Brazil’s Universidade Estadual Paulista, the study found 104 tree species that had never been seen in the Atlantic coastal forest before, and five that are completely new to science.

That number could increase as the study’s results are analyzed more completely, said Wayt Thomas, an ecologist at the New York Botanical Garden who has done similar studies in the Atlantic coastal forest.

Thomas was the first to try cataloging the number of species in small rain forest plots. His 1993 study of a 2.5-acre section in the Brazilian state of Bahia found 458 species, 15 of them previously unknown. During the same year, a similar study of the Amazon rain forest, which is distinct from the Atlantic coastal ecosystem, found 473 species within the same area.

Ecologists are amazed at those numbers because, on average, a similar patch of North American temperate forest contains only two to 20 tree species.

“These are places that are very different from the rest of the disturbed, civilized world,” Thomas said.