The devastation caused by the Black Death in medieval Europe may not have delivered the environmental benefits that could be assumed to follow large-scale human decline, according to new research.
The study may have implications for contemporary conservation strategies
The bubonic plague, which swept across Europe between 1347 and 1353, is estimated to have killed up to one half of the continent's population. The sudden loss of life led to the abandonment of farms, villages and fields, creating what researchers describe as a massive historical 'rewilding' event.
Many modern environmental theories suggest that human activity is inherently damaging to biodiversity, raising the expectation that nature would have flourished in the wake of the plague.
However, an analysis of fossil pollen records from across Europe appears to tell a different story, at least for plant communities.
Untouched landscapes
Jonathan Gordon, Postdoctoral Research Associate at the University of York's Leverhulme Centre for Anthropocene Biodiversity, said: "We 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.
"As farmland was abandoned, traditional land management practices ceased and forests spread. Rather than driving an increase in plant biodiversity, biodiversity plummeted. We only started to see a recovery once human populations rebounded and agricultural activity resumed - a process that took roughly 300 years to return to pre-plague levels."
The findings, published in the journal Ecology Letters, challenge the idea that the richest ecosystems are found in landscapes untouched by humans. Instead, the researchers argue that many of the plant species valued today depend on long-term human disturbance, such as farming, grazing and land clearance.
Recovery
The conclusions may have implications for contemporary conservation strategies, particularly the growing 'rewilding' movement, which often promotes the withdrawal of human activity from landscapes to enable nature recovery.
The research suggests that simply removing people does not automatically lead to healthier or more diverse ecosystems, and this should be considered in future environmental policies.
Co-author Professor Chris Thomas, also at the Leverhulme Centre for Anthropocene Biodiversity, said: "Our work offers a more nuanced perspective on the relationship between humans and nature, indicating that biodiversity and human land use do not have to be in conflict. In many cases, they actually depend on one another."
Good balance
Jonathan Gordon added: "To maintain the many different types of biodiversity that have been associated with European ecosystems over the last few millennia, we have to take a 'patchwork approach', where we have 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 – for example in the Iberian dehesas and montados, as well as Alpine pastures and Hungarian Tanya - so we know it is possible."
