Washington, Sep 17 :
A giant meteorite that wiped out dinosaurs along with evergreen flowering plants 66 million years ago gave rise to deciduous plants – plants that lose their leaves at some point during the year, a significant study reveals.
According to researchers from the University of Arizona, the meteorite impact decimated flowering plants to a much greater extent than their deciduous peers.
Later, the properties of deciduous plants made them better able to respond rapidly to chaotically varying post-apocalyptic climate conditions.
“When you look at forests around the world today, you do not see many forests dominated by evergreen flowering plants. Instead, they are dominated by deciduous species,” explained the study’s lead author Benjamin Blonder.
After analysing a treasure trove of thousands of fossilised leaves of angiosperms – flowering plants excluding conifers – the team reconstructed the ecology of a diverse plant community thriving during a 2.2 million-year period spanning the cataclysmic impact event that believed to have wiped out more than half of plant species living at the time.
The researchers found evidence that after the impact, fast-growing, deciduous angiosperms had replaced their slow-growing, evergreen peers to a large extent.
Living examples of evergreen angiosperms such as holly and ivy tend to prefer shade, do not grow very fast and sport dark-coloured leaves.
Blonder and his colleagues studied a total of about 1,000 fossilised plant leaves collected from a location in southern North Dakota, embedded in rock layers known as the Hell Creek Formation.
“The impact was like a reset button. Some species had properties that enabled them to survive,” Blonder noted.
The findings show that the extinction was not random and the way in which a plant acquires resources predicts how it can respond to a major disturbance.
Potentially, this also tells us why we find that modern forests are generally deciduous and not evergreen, researchers concluded.
The results were published in the journal PLOS Biology.