Amazon survey finds a handful of tree species dominate the largest rainforest


Sun, Oct 20, 2013 - Page 6

The world’s largest tropical forest actually contains a lot of the same kinds of trees, according to research on the Amazon published this week in the journal Science.

Researchers embarked on an ambitious endeavor to catalogue the types of trees seen most often in the vast Amazon basin, which spans parts of Brazil, Peru, Colombia, Guyana, Suriname and French Guiana.

There are about 390 billion individual trees in this expanse known as greater Amazonia, which covers an area about as large as the continental US.

After compiling data from 1,179 forestry surveys, scientists discovered for the first time that the most common tree species in the Amazon is the palm Euterpe precatoria.

They also found that about half the trees in the entire rainforest come from just 227 tree species. The entire Amazon contains about 16,000 different tree species.

In other words, 1.4 percent of the total species make up about half the forest.

Researchers called these common trees “hyperdominants.” They include Brazil nut, chocolate, rubber and acai berry trees.

Some experts believe these trees are so common because they were actively cultivated by indigenous people who have inhabited the area for millennia.

Others, according to report co-author Nigel Pitman, a visiting scientist at the Field Museum in Chicago, “think those trees were dominant long before humans ever arrived in the Americas.”

The count also turned up new hints about rarities in the Amazon, suggesting about 6,000 tree species have populations of fewer than 1,000 individual trees.