When it comes to climate change And Amazon rainforest, the news is never good. Between 2019 and 2020, this news is dominated by images of climates burning in forests and a land covered by climate change and illegal logging.
But scientists still don’t know about the mysterious Amazon.
A new study published Friday Advances in science A case in point. In the study, scientists revealed some startling environmental features in the wettest region of the Amazon, saying rainfall could be harder than we thought.
Neural Networks – In the study, scientists looked at the relationship between air dryness (also known as vapor pressure deficit) and the total initial production of the Amazon.
Total initial production refers to the total amount of carbon that plants in the forest “correct” or take during photosynthesis.
Scientists used observational data over a nine-year period between June 2007 and May 2016, inputting data into a machine learning tool known as an artificial neural network. These networks helped researchers analyze and compare their results with existing results and simulations of how dry air changes Amazon’s ability to act as a carbon sink.
“All I wanted to do was predict different environments and use their input as a model so that I could predict changes in photosynthesis,” says Julia K. Green, author of Laborato des Des Sciences du Climate et al. The opposite.
Simulation vs. Reality – Equipped with their model, Green and his colleagues then compare the general predictions of ground-level simulations to what is actually going on at Amazon.
“These are the ones we’re using to predict climate change and so our predictions can only be as good or accurate as those models,” Green said.
The wet parts of the Amazon boast trees with deep root systems. Models, however, show that plants in this region may be under pressure due to “water shortages” caused by increasingly dry air or soil. That water deficiency can severely affect photosynthesis.
Green explains, “Plants have these tiny holes in their leaves called stomata.
However, “because the plant absorbs some carbon dioxide, it can lose water on the surface of the leaves because the air is dry,” Green said. As a result, the air is becoming “drier, more closed stomata” for water conservation, he explains.
Researchers have assumed – and also made their models – that stopping the stomata from air drying will reduce photosynthesis.
“What we were seeing was a slight dryness with the model simulations, the photosynthesis in these rainfed areas was really declining in the models and we weren’t sure if that seemed necessarily realistic,” Green said.
That’s where the artificial neural networks came in – Green surprised them with their searches: the simulation models were wrong.
“What we’ve seen is that photosynthesis takes place in a really wet area of the forest as the vapor deficit increases. [increases], ”He explains.
Reasons to do with the nature of the Amazon forest. The Amazon has a very “dynamic” forest canopy, Green says, which compensates for the stomata closing, protectively enhancing photosynthesis.
“Once the wind starts to dry, the only way to end the incident is for the forest to spread these old leaves on top of the camp,” Green said. “Newer leaves replace them. And these new leaves have a much greater ability to reproduce light than the new leaves they are replacing.”
A natural elasticity – Amazon works in one of the most important carbon sinks in the world. And that carbon sink depends on photosynthesis for survival.
These results, however, suggest that Amazon maintains its own natural resilience during indicator winds. However, research has shown whether Amazon is better positioned against extreme weather events such as climate change-related droughts, Green said.
“This study, while showing that forests are more resilient than our approach to air dryness and what has been portrayed, does not mean that we have not seen so far that it is going to dry out in layers that are going to be fine,” says Green.
Abstract: Models of the Earth system predict that increasing atmospheric and soil dryness will reduce photosynthesis in the Amazon Rain Forest, with major implications for the global carbon cycle. Using situation monitoring, solar-powered fluorescence, and nonlinear machine learning techniques, we show that this is not really the case: in most parts of the region, photosynthesis and biomass continue to increase with the dryness of the atmosphere, a decrease in CO2 dissipation . These results can be explained by changes in the larger canopy properties, especially in the dry season when new leaves have a higher luminosity than their replacement leaves, compensating for the negative stomatal response to increased dryness. As atmospheric aridity increases with climate change, our study of how ecosystem photosynthesis responds to atmospheric aridity in very humid regions highlights the importance of land reclamation to accurately measure land carbon sinks.