Dinosaur-killing asteroids are today’s rain forest irt


Colombia looked at the rain forest Very different million 66 million years ago. Currently, the wet and biodiversity ecosystem is jammed with trees and it is covered in a dense, light-blocking canopy of leaves and branches. Significantly, no Dinosaurs. Before the dinosaurs moved away with the Chixulab effect, indicating the end of the Cretaceous period, things looked very different. Plant coverage in this region was relatively low, and an incentive for conifers to call it home.

Uses Fossilized From the remains of plants, a team of researchers studied the past of the rain forest and how the asteroid gave birth to today’s rain forest. The Study, Published Science On April 1, scientists from the Smithsonian Tropical Research Institute (STRI) in Panama led and scientists from the Neguni Institute for Plant Conservation Science and Action at the Chicago Botanic Gardens.

“The forest disappeared due to environmental disasters … and then, the returning plants were mostly dominated by flowering plants,” said Manica Carvalho, the first author of STRI and the first author and joint postdoctoral fellow at Columbia Universidad del Rosario. Ars

The study began 20 years ago, with parts of the team collecting and analyzing 6,000 leaves and 50,000 pollen fossils from Colombia. Observing these fossils enables the team to detect the presence of both types of plants before and after the asteroid’s impact. “It took us a long time to gather enough information to have a clear picture of what was going on at the time of our extinction,” Carvalho told Ars, covering the region’s biodiversity between 722 million and 56 million years ago, both before and after the impact.

Although the study discusses Colombian fossils, Karbalho said researchers can get a fair idea of ​​what happened to rainfall elsewhere in Central and South America, although the impact of the asteroid varies from region to region. “It simply came to our notice then. We still don’t know why some places were more affected than others, “he said.

Later Asteroids Hit the earth, almost half of Colombia’s plant species have become extinct. The pollen fossils of this species have stopped the past presence of that point. Rainforests began to be occupied by ferns and flowering plants that were less common than they are today in pre-impact. The coniferous trees died effectively by comparison.

Outside of the presence of conifers, the rainforests of the past were probably much more sparse than their modern parts. Current rainforests have dense canopies and the plants in them are very close together, which means more plants are sending water into the atmosphere. This leads to higher levels of humidity and cloud coverage. According to Carvalho, the relative lack of moisture in previous forests meant that these areas were probably much less productive than they are today.

However the low-productivity forest remained in place until the asteroid hit. “After the impact we see that forests change their structure,” he said.

Researchers have some ideas about how this change happened. The first is the Dinosaurs The forests become more dense – there may be very few animals with the help of plants or brushes, so the leaves may be relatively removed. The second idea is that soon after the collision of the asteroid with the planet, a selective extinction of conifers occurs in the tropics – they may bear less good fruit than their flower peers after being affected.

The third is that the aftermath of a disaster can irrigate the soil. Tsunami events after impact can carry debris and sediment from the surrounding carbon-rich, shallow marine areas. The fire could send ash into the burning atmosphere and act as a kind of fertilizer when it finally settles in the ground. Carvalho said flowering plants grow better than conifers in high-nutrient soils. He further mentioned that all these assumptions or all two assumptions can be true at the same time.



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