Uncovering the Past: How Global Warming is Impacting Plant Species – Insights from Ancient DNA

Global warming is causing a rapid loss of plant species, with roughly 600 plant species having died out since 1750, twice the number of animal species lost. The Alfred Wegener Institute has conducted two recent studies to investigate which plant species are hit hardest and how altered biodiversity affects plant interactions.

Using fragments of plant genetic material (DNA) deposited in lake sediments, researchers were able to gain new insights into how the composition of flora changed 15,000 to 11,000 years ago during the warming at the end of the last ice age. This period is considered to be the last major mass extinction event before today, offering a glimpse into what might await us in the future. The findings of these studies have been published in the journal Nature Communications.

Prof Ulrike Herzschuh from the Alfred Wegener Institute highlights the importance of studying plant extinctions, noting that until recently, suitable methods for investigating the extinction of plant species in detail were lacking. By analyzing old DNA from sediment cores taken from lakes in Alaska and Siberia, researchers were able to reconstruct changes in vegetation in these regions.

The research shows that the composition of plant species changed significantly at the end of the last ice age, accompanied by fundamental changes in ecological conditions. A connection between temperature and plant-to-plant interactions was identified, with plant species supporting each other in cold climate periods and mainly competing during warm periods.

In a warmer climate, woody plant species dominate, leading to a decline in plant diversity due to the migration of trees and shrubs into tundra regions. This shift in vegetation poses a threat to cushion plants, which play a pivotal role in high latitudes today.

The studies also revealed that certain types of vegetation disappeared entirely at the end of the last ice age, such as the mammoth steppe. Grasses and shrubs are at a higher risk of extinction in a warming world compared to woody plant species. The extinction rate was highest at the beginning of the current warm phase, indicating that the full impacts of human activities may not be apparent until the distant future.

These findings offer crucial insights into how environmental changes associated with warming affect biodiversity and highlight the importance of understanding ecological interactions to predict the impacts of climate change. By unlocking information from old DNA in sediments, researchers can better assess ongoing changes in Arctic ecosystems and make informed decisions to protect plant species at risk of extinction.