DNA found in lake bottom offers historical clues regarding impact of an

first_img The researchers note that understanding the full impact of an invasive species on an environment is difficult, involving many factors, one of which is generally a long timescale. In this new effort, the researchers found an environment with few interacting variables and a natural historical record—DNA found in a lake bottom.The environment was the Kerguelen Islands, situated in a remote southern part of the Indian Ocean. The invasive species was a type of rabbit introduced to the islands as a food source in 1874 by a group of scientists—they were there to study the transit of Venus, but they left behind several rabbits that quickly multiplied because there were no predators. Since that time, the rabbits have spread across much of the main island of Grande Terre, wreaking havoc on the delicate ecosystem.To learn more about the impact the rabbits have on the island, the researchers collected samples from the bottom of a lake which contained samples of plant DNA. They found samples dating back several hundred years, and were able to follow the events that had transpired.They deduced that the region had been relatively stable for hundreds of years prior to the arrival of the rabbits. Then, in the early 1940s, when the rabbits made their way to that part of the island, things changed. Prior to their arrival, the dominant plant was Azorella selago—after their arrival, plant diversity plummeted. They also noted that erosion dramatically increased, as well.The team notes that erosion did eventually level off, but the ecosystem was unstable, and remains that way today in spite of efforts to eradicate the rabbits by the French Government. Instead, due to more human traffic in the area, other invasive species have made their way to the islands. Still, the island offers a unique opportunity to study the impact of an invasive species in a near-pristine environment. Citation: DNA found in lake bottom offers historical clues regarding impact of an invasive species (2018, May 10) retrieved 18 August 2019 from https://phys.org/news/2018-05-dna-lake-bottom-historical-clues.html Invasive Burmese pythons shown to be reducing marsh rabbit population in Everglades Journal information: Science Advances A team of researchers from France, Italy and Norway has found a natural historical record of the impact of an invasive species of rabbit on a remote Indian Ocean island. In their paper published on the open access site Science Advances, the researchers describe their efforts to learn more about the environmental impact of an invasive species. Credit: CC0 Public Domainlast_img

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