Forest ecosystems at risk of collapse



by LORENZO CIOTTI

Forest ecosystems at risk of collapse

According to a study just published in Nature, the climate crisis is causing the collapse of 23% of the forest ecosystems still intact on the planet. The researchers explain: "We integrate satellite vegetation indices with machine learning to show how forest resilience, quantified in terms of critical slowdown indicators, has changed over the period 2000-2020.

Resilience of forest ecosystems which is defined as the ability to resist and recover from natural and anthropogenic disturbances. and tropical forests and those in the driest areas are experiencing a significant decline in resilience, probably linked to greater water constraints and climate variability.

Forests in the northern hemisphere at higher latitudes generally have an inverse trend, that is, they are benefiting from the increase in temperatures and CO2 in the atmosphere, even if there are marked differences at the local level.

About 23% of intact and undisturbed forests have already reached a critical threshold and are undergoing further degradation of resilience. The factors are the increase in the average temperature especially. "

Conservation of forest ecosystems

Primary forest means an intact forest, whose vital functions and ecosystem subsists in its original state.

This forest has never been touched by human activities of an industrial nature or by agricultural conversion. Primary forest is a mature forest and usually hosts the highest degree of biodiversity. Secondary forest is a forest that is heavily disturbed by natural and non-natural causes.

It can be a forest that has undergone several waves of selective cutting, or more frequently a young forest that has regrown after clear cutting operations, or after a cycle of agriculture based on slash and burn. Secondary forest is usually characterized by less developed cover, younger trees and less diversity, with a greater presence of pioneer species.

Often, due to the lesser cover, the undergrowth of a secondary forest, especially in the tropics, takes on the character of a jungle, being more dense. Intact forest areas still extend over 13 million square kilometers, 8% of the land area: half of the original forests that covered the planet at the end of the ice age are lost forever, and most of the remaining forests are fragmented.

in small areas. Frontier forests or intact forest landscapes are forest-based ecosystems that cover an area that exceeds 500 square kilometers and whose natural features are not affected by human intervention.