A James Cook University scientist says a new study shows more than half of all tree species in the world's most diverse forest -- the Amazon -- may be globally threatened.

Long-time Amazon researcher, Professor William Laurance from JCU, is a co-author of the study, published this week in the journal Science Advances.

It compared data from forest surveys across the Amazon with maps of current and projected deforestation to estimate how many tree species have been lost, and where.

Professor Laurance said the study suggests existing Amazonian parks and reserves, if properly managed, could protect many of the threatened species. But it was not a forgone conclusion.

"It's a battle we're going to see play out in our lifetimes," he said. "Either we stand up and protect these critical parks and indigenous reserves, or deforestation will erode them until we see large-scale extinctions."

The findings were announced by a research team comprising 158 researchers from 21 countries, led by Hans ter Steege of Naturalis Biodiversity Center in the Netherlands and Nigel Pitman of the Field Museum in Chicago, USA.

The authors say protected areas and indigenous territories now cover over half of the basin, and are likely to contain sizeable populations of most threatened species.

"This is good news from the Amazon that you don't hear enough of," said ter Steege.

"In recent decades Amazon countries have made major strides in expanding parks and strengthening indigenous land rights," he said. "And our study shows this could have big benefits for biodiversity."

However, the authors caution that Amazonian forests and reserves still face a barrage of threats, from dam construction to wildfires and droughts intensified by global warming.