By studying vegetation landscapes across North America, scientists have concluded that their condition is indicative of a “preparation” for a mass extinction that has not been observed since the retreat of glaciers and the arrival of humans about 13,000 years ago.
The researchers used data from 14,189 fossil pollen samples to determine the resilience of landscapes. To do this, they paid attention to two factors: residence time - the duration of the existence of specific biomes, such as forests and grasslands, and recovery - how well biomes recover from wildfires and other disasters.
“Our work shows that landscapes today show low resilience, anticipating potential extinctions in the future,” the scientists write in their work. "Conservation strategies that increase the resilience of ecosystems can mitigate these extinction risks."
In the course of their work, scientists have studied 12 major plant biomes in North America over the past 20,000 years. They found that landscapes today show lower resilience than at any time since the end of the Pleistocene.
For example, it takes more than three centuries to restore a biome, and not all of them eventually bounce back. The study found that only 64% of landscapes are recovering to their original biome, with arctic systems being the least likely to recover. Also, scientists have noticed that landscapes are restored most quickly if the ecosystem contains a high biodiversity of plants.
The resilience of the landscape, the ability of habitats to conserve or quickly recover in response to disasters, helps maintain biodiversity during periods of climatic and ecological change, the researchers note. That is why scientists say that it is very important to start introducing measures to restore biodiversity so that natural systems can survive global changes on Earth.