Black Death had dramatic effect on species diversity as humans abandoned farmland, study finds

When millions of people died in Europe during the Black Death, biodiversity suffered too, new research suggests.

The findings suggest that human activities once promoted biodiversity in the landscape — and experts say we could use these findings to boost biodiversity in our modern agricultural landscapes.

The 14th century was a tumultuous time for the people of Europe.

Persistent cold, wet weather at the beginning of the century led to widespread agricultural failures and unprecedented levels of starvation in what became known as the Great Famine from 1315 to 1317.

This was followed by the Black Death , an epidemic of bubonic plague caused by the bacterium Yersinia pestis that killed more than a third of Europe's population.

As a result of the widespread deaths and resultant social upheaval, large swaths of agricultural land were abandoned.

Population levels didn't begin to recover until the 16th century .

The Black Death era is the perfect opportunity to look at the effects of humans on biodiversity over a longer period, Jonathan Gordon , a paleoecologist at the Leverhulme Centre for Anthropocene Biodiversity at the University of York and first author of the paper, told Live Science.

In the study, which was published March 4 in the journal Ecology Letters , the researchers compared more than 100 European pollen records that included about 4,600 samples.

The records came from sites ranging from the lowlands of France and uplands of the southwest United Kingdom to the Swiss Alps.

The pollen records "give us information on the past diversity of the plant records," Gordon said.

For example, cereal grains ‪—‬ such as wheat, barley and rye ‪—‬ were a fundamental part of medieval agriculture .

The representation of pollen from these types of crops in the pollen record points to historic land use.

The researchers divided the pollen data into three categories based on the presence of cereal pollen: places where agricultural production went up, places where it went down, and places where there was no evidence of cereal cultivation.