The sudden loss of nearly half of Europe’s population between 1347 and 1353 due to the bubonic plague surprisingly led to a decline in plant diversity across the continent, a new study reveals.
Until now, it was widely believed that environmental benefits follow large-scale population decline, as human activity is thought to be inherently damaging to biodiversity.
Researchers previously held that the sudden loss of life caused by the Black Death in medieval Europe led to the abandonment of farms, villages and fields, creating a massive historical “rewilding” event.
However, a new analysis of fossil pollen records from across Europe tells a different story.
“As farmland was abandoned, traditional land management practices ceased, and forests spread,” said Jonathan Gordon, an author of the study published in the journal Ecology Letters.
“Rather than driving an increase in plant biodiversity, biodiversity plummeted,” said Dr Gordon from the University of York’s Leverhulme Centre for Anthropocene Biodiversity.
In the study, researchers examined plant diversity in the centuries before and after the Black Death and found that biodiversity declined significantly in the 150 years following the pandemic.
Scientists argue that many of the plant species valued today depend on long-term human disturbance, such as farming, grazing and land clearance.
The contemporary “rewilding” movement often promotes the withdrawal of human activity from landscapes to enable nature recovery.
The findings challenge the idea that the richest ecosystems are found in landscapes untouched by humans, and may have implications for modern conservation strategies.
They imply that simply removing people does not automatically lead to healthier or more diverse ecosystems.
“Our work offers a more nuanced perspective on the relationship between humans and nature,” said Chris Thomas, another author of the study.
The research indicates that biodiversity and human land use do not have to be in conflict.
“In many cases, they actually depend on one another,” Dr Thomas said.
Scientists call for a “patchwork approach” to maintain the many different types of biodiversity that have been associated with European ecosystems over the last few millennia.
In this approach, areas are to maintain a mosaic of crops, woodlands, pastures, ponds, and lakes and so on, co-existing in the same landscape.
“It is true that humans can go too far, and we have seen that with extensive crop monocultures and overgrazed landscapes, but we have models where a good balance has been achieved between humans and biodiversity,” Dr Gordon said.
“For example, in the Iberian dehesas and montados, as well as Alpine pastures and Hungarian Tanya, so we know it is possible,” he said.
