New research shows the Amazon rainforest is much more geographically sorted than researchers ever imagined.

A team of scientists demonstrated the "hidden tapestry" of chemical variations in the region that is linked to which plants grow where, the Carnegie Institution for Science reported.

"Our findings tell us that lowland Amazon forests are far more geographically sorted than we once thought," said Carnegie's Greg Asner. "It is not simply a swath of green that occurs with everything strewn randomly. Place does matter, even if it all appears to be flat and green monotony at first glance."

The Amazon rainforest holds thousands of plant species, each with their own unique chemical fingerprint used for functions such as fighting off predators, attracting pollinators, and even adapting to climate change. The region itself boasts an "underlying mosaic" of geologic and hydrologic variation that affects the chemical diversity of the plants. Understanding this phenomenon is key to realizing how the ecosystem functions on a large scale. To gain these insights, the researchers used data from the Carnegie Airborne Observatory to create maps of the rainforest's canopy chemistry.

"This is the first time that so many chemicals have been measured and mapped in any forest ecosystem on Earth," Asner said. "No one has done the mapping we have achieved here, which enabled a discovery that the lowland Amazon is anything but monotonous or similar everywhere."

The researchers observed the chemical changes along the Madre de Dios River and the Tambopata River as well as the landscape's "microscale" topography. They found even minute changes in elevation had an influence on the greenery.

"Looking at the lowland Amazon with this kind of detail, you can see back in time, from the way the topography was shaped millions of years ago, which still affects soils and mineral availability today, to the way that different species evolved to take advantage of this great variety of subtly changing conditions," Asner said. "And we can peer into the future and see how quickly human activity is changing the kaleidoscope of diversity that has been uniquely shaped over millions of years."

The findings were published in a recent edition of the journal Nature Geoscience.