NASA’s space laser, dubbed GEDI, has transformed the way we comprehend rainforests, bringing to light a simpler structure with a primary leaf concentration at 15 meters. This discovery holds the potential to remarkably enhance our understanding of biodiversity, how species adjust to climate change, and the carbon-holding capacity of forests.

The pioneering and comprehensive depiction of the world’s rainforests provided by NASA’s GEDI space laser has empowered researchers to delve deeper into the intricacies of these ecosystems.

Decoding the Rainforest Canopies: A Journey of Discovery

The rainforest canopy, home to most of the world’s species, remains less explored than the Martian surface or the ocean’s depths. However, with GEDI, NASA’s space laser, this is on the cusp of transformation, offering an unprecedentedly detailed view of the rainforests.

In a paper titled “Tropical forests are mainly unstratified, especially in Amazonia and regions with lower fertility or higher temperatures” recently published in the Environmental Research Ecology journal, the laser’s findings are meticulously elaborated. Authored by researchers from the U.S., U.K., and Singapore, Christopher Doughty, a professor at Northern Arizona University’s School of Informatics, Computing, and Cyber Systems and the primary author of the study, emphasizes the criticality and necessity of this research to broaden our understanding of tropical ecosystems.

The paper includes a graph illustrating canopy information gathered from GEDI. Credit: Nicolle Fuller and Chris Doughty

Unveiling the Significance of the Rainforest Structure

Doughty acknowledges the paradox of our minimal knowledge of the rainforest structure that is home to the majority of the world’s species. He asserts, “Rainforest structure is essential as it determines how animals access resources and evade predators, and these findings will contribute to our comprehension of tropical forest animal’s vulnerability to climate change.”

Historically, the understanding of forest canopies has drastically evolved. Initially, western visitors perceived tropical forests as nature abhorring a vacuum since vegetation seemed eager to occupy every open space. Later, scientific studies categorized the lush vegetation into distinct forest layers, but this was limited to only a few extensively researched locations, leaving the structure of most tropical forests largely unknown.

The Advent of GEDI

NASA introduced GEDI, short for Global Ecosystem Dynamics Investigation, as a groundbreaking tool for investigating ecosystems.

Hao Tang, a professor at the National University of Singapore (NUS) and a co-author of the paper, distinguishes GEDI from conventional satellites. He states, “A primary differential factor is GEDI’s capability to measure three-dimensional canopy structure. Although conventional satellites offer valuable data regarding land cover and canopy greenness, they often lack the detailed vertical information provided by GEDI. This information is fundamental to comprehending ecosystem dynamics, carbon storage, and biodiversity, aspects typically obscured in regular satellite images.”

Launched in late 2018, NASA’s GEDI emits an invisible laser from the International Space Station into Earth’s forests, thousands of times a day. Depending on the reflected energy, GEDI can generate an intricate 3D map illustrating the locations of leaves and branches in a forest and their changes over time. This data will enhance our understanding of forest biomass, carbon storage, and the effects of disturbances – vital information to comprehend Earth’s carbon cycle and its evolution.

Uncovered Findings and their Implications

The authors analyzed GEDI data from all tropical forests and found that the structure was more straightforward and more exposed to sunlight than previously assumed. The data also uncovered that in most tropical forests (80% of the Amazon and 70% of Southeast Asia and the Congo Basin), the leaf peak was at 15 meters, and not at the canopy top as early researchers suggested. Despite forest variations, a consistent finding was that deviation from ideal conditions, like lower fertility or higher temperatures, resulted in shorter, less layered forests with lower biomass.

Doughty expressed surprise at the dominance of this structure, which deviates from traditional textbook knowledge. He said, “These findings will not only help us comprehend how the millions of species residing in a rainforest canopy might adapt to changing temperatures, but also how much carbon these forests store and their efficacy in combating climate change.”

Reference: “Tropical forests are mainly unstratified especially in Amazonia and regions with lower fertility or higher temperatures” by Christopher E Doughty, Camille Gaillard, Patrick Burns, Jenna Keany, Andrew Abraham, Yadvinder S Malhi, Jesus Aguirre-Gutierrez, George Koch, Patrick Jantz, Alexander Shenkin and Hao Tang, 13 July 2023, Environmental Research Ecology. DOI: 10.1088/2752-664X/ace723

Frequently Asked Questions (FAQs) about NASA’s GEDI Space Laser

More about NASA’s GEDI Space Laser

• NASA’s GEDI Space Laser
• Global Ecosystem Dynamics Investigation
• The Role of Rainforests in Climate Change
• Understanding Forest Biomass and Carbon Storage
• Biodiversity in Rainforests