How do higher temperatures, pollution and other changes in the environment affect biodiversity? To find out, scientists developed a ‘time machine’. And not to fly into the future, but to take a look into the past. What they saw was hardly reassuring.
German and British scientists used sediments from the bottom of a lake in Denmark to create this so-called time machine. This created a hundred-year-old library containing all information about biodiversity, chemical pollution and climate change.
The changes in water quality in this lake had been well recorded for a long time, making it a perfect natural experiment to test the biodiversity time machine. The sediments clearly showed what changed in the lake over time from the pure clean environment at the beginning of the Industrial Revolution to the present.
The researchers used genetic material left behind by animals, plants and bacteria in the sediments to map the entire freshwater community. With the help of AI, they analyzed the information in combination with climate and pollution figures to figure out how to explain the massive loss of species in the lake.
Back in time
“We took sediments from the lake bottom and used biological data in the sediment as a time machine, allowing us to go back in time to paint a detailed picture of biodiversity over the past century at one-year resolution. By combining the biological data with pollution levels and climate change data, we were able to identify the factors that have had the greatest impact on biodiversity,” explains lead researcher Luisa Orsini of the University of Birmingham.
The research is aimed at protecting biodiversity. “However, it is not realistic to protect every species without impacting people’s lives, but with the help of AI we can prioritize the conservation of species that are particularly useful to the ecosystem. At the same time, we can identify the biggest polluters and promote regulation to combat the emissions of chemicals that have the greatest negative impacts. This can not only help us preserve the biodiversity that still exists, but may also promote its recovery. Biodiversity supports many ecosystems, from which we all benefit,” said the researcher.
Pesticides, such as insecticides and fungicides, together with a temperature increase of 1.2 to 1.5 degrees Celsius caused the most damage to biodiversity. Remarkably, the DNA in the sediments showed that the lake began to recover over the past twenty years. The water quality improved because the land around the lake was used less for agriculture. Yet biodiversity is still far from being at its previous level.
“The loss of biodiversity caused by pollution and higher water temperatures may be irreversible. The species that were found in the lake a hundred years ago but have now disappeared will not all return. It is impossible to restore the lake to its original state, even if there is now some recovery. This research shows that if we fail to protect biodiversity, much of it may be lost forever,” it said.
Predict the future
But the researchers’ time machine can also help predict the future. “By learning from the past, our models can help predict the likely loss of biodiversity if we continue as now or switch to other climate scenarios. We have demonstrated the value of AI-based methods to explain past biodiversity loss. As new data becomes available, AI models can improve our predictions even further,” said researcher Jiarui Zhou of the University of Birmingham.
This research was actually an experiment to test the ‘time machine’. Now that it has proven to be so successful, the researchers want to study many more lakes in England and Wales. This way they can see whether patterns emerge and whether pollution and climate change have similar effects on lake biodiversity everywhere.