The research published in Nature Plants by a global team of tropical forest scientists shows that the average size of trees in Amazon forests has increased over recent decades. The team of almost a hundred researchers monitored the size of trees in 188 permanent plots and discovered that the increase has continued for at least 30 years.

The study is the result of an international partnership of more than 60 universities in South America, the UK and beyond—including the Universities of Birmingham, Bristol, and Leeds.

Co-author of the study, Professor Beatriz Marimon, from Universidade do Mato Grosso, who coordinated much of the Brazilian data collection in southern Amazonia, commented, "This is a good news story. We regularly hear how climate change and fragmentation is threatening Amazonian forests. But meanwhile, the trees in intact forests have grown bigger; even the largest trees have continued to thrive despite these threats."

The study found that both large and smaller trees have increased in size, consistent with benefiting from fertilization by increased atmospheric carbon dioxide.