One of the largest field experiments ever conducted is providing the best evidence yet in support of a key Darwinian theory—that interactions between species are stronger toward the tropics and at lower elevations.
An international research team used a simple experiment that mimics how plants and animals interact with each other—leaving seeds out for 24 hours to see how many are consumed by animals. Seven thousand seed beds were deployed across a huge geographic area, with 70 sites cutting across 18 mountains from Alaska to the Equator.
“Theory predicts that interactions among species—like predation and competition—will be strongest in the warm, productive, biodiverse ecosystems of the tropics and at low elevations,” says lead author Anna Hargreaves, who launched the project while at UBC’s Biodiversity Research Centre. She is now a professor at McGill University.
“For example, the spectacular diversity of tropical trees is thought to result partly from stronger interactions between plants and the animals that prey on their seeds, which shapes how and where plants grow and adapt.”
Read more at University of British Columbia
Image: In one of the largest field experiments ever conducted, an international team measured seed predation at 70 sites across the Americas. (Credit: Anna Hargreaves, University of British Columbia, McGill University)