The team of Australian and international scientists is strongly urging the protection of primary forests as a result of its findings.
The study, published in the scientific journal Nature, says most forms of forest degradation have an overwhelmingly detrimental effect on tropical biodiversity.
The report compared human impacts on biodiversity across key forested regions across the world.
“The conclusion is very clear,” report co-author Professor Corey Bradshaw from the University of Adelaide said.
“Undisturbed primary forests are the only ones in which a full complement of species can thrive.”
The team emphasised that until now some people believed that revegetation and other conservation programs in secondary forests would be enough to help preserve or return most species.
“It’s not that secondary forests have no biodiversity value. They are just less valuable than primary forests. We should be focused on protecting primary forests as much as possible.”
Professor Bradshaw’s colleagues also emphasised that most forms of forest degradation have an overwhelmingly detrimental effect on biodiversity.
“The study shows that the impact of human interference in those forests is too strong. We’re kidding ourselves if we think the damage can be reversed,” Professor Barry Brook also from the University of Adelaide said.
South-East Asia is the worst affected area, suffering the greatest losses of biodiversity of any tropical region over the past 50 years.
The report’s authors said that while South-East Asia must remain one of the top priority regions, that doesn’t mean other areas can be ignored.
They suggest the expansion and greater enforcement of protected areas.
“We have already invested substantially in setting up parks. So expanding them and making them more effective might be practical,” one of the study’s leaders, PhD student Tien Ming Lee said.