Rufous-tailed JacamarDANIEL KARPBirds living in the rainforests of Costa Rica represent around 4.1 billion years of evolutionary history, while those that occupy nearby farmland can represent as little as 3.3 billion years, according to a paper published today (September 11) in Science. While the results suggest that agriculture diminishes phylogenetic diversity, researchers have also found that farms with mixed agriculture support far greater diversity than those with intensive monocultures.
“We’ve known for a while that intensive agricultural monocultures tend to have lower numbers of different species than diversified agricultural systems, which themselves tend to have lower numbers than undisturbed forests,” said Walter Jetz, a professor of global biodiversity, ecology, and conservation at Yale University who was not involved in the work. “What this study now adds is that, it is not just the count of different species but also the amount of evolutionary history, or phylogenetic diversity, that is different.” That is, farms tend to “harbor less of the avian tree of life,” he said.
Assessing the biodiversity of a given environment was traditionally accomplished by counting the number of species present, said Daniel Karp, a postdoctoral scientist in the department of Environmental Science, ...
