A massive satellite study reveals that tropical forests across the Amazon, Africa, and Southeast Asia respond differently to heat and drought.
Picture a tropical forest, and you probably see one thing: a dense, dripping, impossibly tall green wall repeating itself from the Amazon to the Congo to Borneo.
A massive new satellite study says that picture is wrong in a scientifically important way. Forests on different continents don’t just look different. They also respond to heat, drought, and soil conditions in fundamentally different ways.
This means the climate rules that govern an Amazonian forest don’t necessarily apply to forests a few thousand miles away in Africa or Southeast Asia.
The research comes from a team affiliated with the Smithsonian Tropical Research Institute, the University of Maryland, NASA, and Brazil’s Universidade Federal dos Vales do Jequitinhonha e Mucuri.
Millions of measurements from space
The team pulled together 16 million satellite estimates of aboveground biomass. NASA’s GEDI mission collected the estimates in 2020 by firing laser pulses at forest canopies to map their three-dimensional structure from orbit.
The dataset covered the Amazon, the Congo Basin, and Southeast Asia. It gave researchers something no ground survey could match: a genuinely global comparison of how environmental conditions shape forest carbon storage.
__________________________________________________________________
Read Also : New mango varieties hit shelves after frustrating wait ends for growers
__________________________________________________________________
“This study definitively shows that tropical forests on different continents respond differently to climate,” said Helene Muller-Landau, a co-author of the study and a staff scientist at the Smithsonian Tropical Research Institute in Panama.
“This is consistent with the idea that the very different historical climates and evolutionary trajectories in Africa, Asia, and the Americas have enduring legacies in how forest biomass varies with climate.”
“Our GEDI spaceborne LIDAR mission, which uses laser pulses to measure the three-dimensional structure of forests, made it possible to connect aboveground forest biomass measurements with climate, soils, and topography,” said lead author Matheus Nunes, an assistant research professor at the University of Maryland.
Forests follow their own rules
Not every tropical forest fits the postcard image. Trees with lightweight wood, such as balsa, hold far less carbon than dense hardwoods such as rosewood or ebony, even when they stand side by side in the same climate zone.
Some tropical forests are packed with towering giants, while others consist entirely of much smaller trees. What grows where depends heavily on soil conditions and terrain. The ground may be flat or mountainous, parched or waterlogged.
The study found that identical climate shifts produced very different biomass outcomes depending on the continent and the conditions surrounding each forest.
“The study underscores the major role that events over a geological time scale, including landscape and climate changes, have shaped the extant tropical rainforest,” said Carlos Jaramillo, a paleobiologist at the Smithsonian Tropical Research Institute.
“It is not enough to have global analyses that show how the environment, including climate, affects the structure of vegetation, as these effects are very heterogeneous and depend strongly on the local context,” Nunes added.
“Therefore, we need local analysis and local experts who know the landscape well to make better predictions of the effects of climate on tropical forests.”
________________________________________________________________________
Read Also : Climate Change Performance Index 2021: India slips down by one position to 10th rank,…
________________________________________________________________________
Continents follow different climate rules
In general, hotter sites stored less biomass, but the size of that decline varied dramatically by region.
Congo Basin forests were the most temperature-sensitive of the three. Amazonian forests fell somewhere in the middle, while Southeast Asian forests barely responded to temperature shifts.
Water told the opposite story. Southeast Asian forests were by far the most sensitive to drought, with biomass falling sharply as sites became drier.
Amazonian forests behaved differently, with biomass peaking at intermediate levels of aridity rather than declining steadily as conditions became drier. African forests, meanwhile, showed almost no response to aridity.
Soil and terrain added another layer of complexity.
In the tallest forests on Earth, where trees stretch beyond 70 meters, drought and heat did not cause the greatest biomass losses. Instead, storms, lightning strikes, and windthrow knocked giant trees to the ground.
Why earlier studies disagreed
The findings help settle a debate that has simmered in forest ecology for years. Earlier studies appeared to contradict one another on how climate shapes biomass.
Rather than reflecting flawed methods, the researchers argue, much of that disagreement revealed something real: forests on different continents operate by different rules.
“Africa has a drier history, Southeast Asia has wetter history, and these histories have shaped what species are there, and how they respond to climate,” Muller-Landau said.
“So the fact that the forests look different in fascinating ways between Africa, America, and Asia is not just a curiosity – it’s fundamental to understanding the forests.”
“New networks of forest plots, such as the GEO-TREES network, which use the same methods to measure forest carbon at different sites, will be important as we continue to verify satellite carbon estimates,” she concluded.
NOTE – This article was originally published in Earth and can be viewed here
Tags: #africa, #amazon, #carbon, #climate, #climatechange, #environment, #forest, #getgreengetgrowing, #gngagritech, #greenstories, #nature
