AI Helps Us Better Understand (and Protect) Forests

The coordinated work of over 150 scientists, complemented by the substantial computational capabilities of AI, seeks to enhance our understanding of forests. The primary goal is to investigate the evolving nature of these ecosystems and develop effective measures for their conservation. The results of this challenging research – promoted by the researchers of the Global Forest Biodiversity Initiative – have been published in three scientific articles. Two of these articles have been published in Nature, while the third finds its place in Nature Plants.

"Through the collaborative efforts of hundreds of researchers science has achieved a significant advancement in the understanding of the world’s forest ecology and in emphasising the need to protect them. Without the supercomputer’s computing power and AI, we would have needed decades and the workforce of thousands, all without the certainty of obtaining reliable estimates," says Roberto Cazzolla Gatti, professor at the Department of Biological, Geological, and Environmental Sciences of the University of Bologna and co-author of the three studies.

ALIEN SPECIES AND NATIVE DIVERSITY
The first topic that the researchers focused on was the invasion of non-native trees: this is an essential phenomenon to understand, to safeguard native ecosystems and limit the spreading of invasive species. Which factors are triggering and facilitating this process?

By analysing trees’ databases at a global level, researchers determined that temperature and precipitations serve as strong predictors of the invasion strategy: non-native species effectively invade an area when their environmental preferences align with those of the native community in conditions of extreme cold or drought.

However, there is another element which facilitates the diffusion of invasive species even more: human activity, particularly in environments such as managed forests or near roads and seaports.

"The invasion of a place by non-native trees is not only predicted by anthropic factors, but its gravity is also ruled by native diversity: a greater diversity reduces the gravity of the invasion. Rather than combating alien species when it's already too late, our focus should be on safeguarding the health of forests. This proactive approach, similar to other ecosystems, would pose greater challenges for alien species to spread and invade", says Professor Cazzolla Gatti.

CARBON SINKS?
Nowadays we recognise the crucial role of protecting forests in preserving their capacity to capture carbon dioxide and serve as Earth’s carbon sink. However, what is the global potential of carbon that forests can store?

The second study, published in Nature, focuses on that topic, revealing that the global forest carbon is currently considerably below the natural potential. Almost 61% of this potential is located in areas hosting existing forests, where the safeguard of the ecosystem allows them to recover until reaching maturity. Instead, the remaining 39% is located outside urban and agricultural lands, but in regions in which forests have been either removed or fragmented.

"Forests alone cannot substitute the necessary reduction of CO2 emissions in the atmosphere. However, our results support the idea that the conservation, recovery, and sustainable management of different forests can offer precious contributions to reach the global goals for climate protection and biodiversity. For the first time, we were able to verify that, despite the regional variations, predictions on global scale exhibit remarkable coherence, with only a 12% difference among the estimates obtained from the ground and those derived from the satellite. So, forests serve as a major earth’s carbon sink, however anthropogenic changes in climate and land use reduce their absorption capacity", explains Professor Cazzolla Gatti.

LEAF TYPES AND CLIMATE CHANGE
While conducting research and analysis, researchers have gone even further. They have tried to understand the factors that influence the global variation in tree leaves and the role of tree species in terrestrial ecosystems, including the cycle of carbon, water, and nutrients.

As a result, researchers have discovered that the global variation between evergreen and deciduous trees is mainly caused by isothermy and soil characteristics. At the same time, the type of leaves is determined by temperature. In particular, their estimate reveals that 38% of the world’s trees are evergreen with needle-shaped leaves, while 29% are broadleaved and 27% are broadleaved deciduous and 5% have needle-shaped leaves.

Professor Cazzolla Gatti explains, "Depending on future greenhouse gas emissions, by the end of the century, 17 to 34 percent of forest areas may undergo climate conditions that currently support a different type of forest: up to a third of the earth’s green areas will likely experience intense climate stress. The results of this study can improve the predictions on the functioning of forest ecosystems and the carbon cycle by quantifying the distribution of tree leaf types and corresponding biomass, identifying the areas in which climate change will exert greater pressure on the current leaf types."