The grass isn’t growing greener.
A globe-trotting research team has found that fertilizers used in farming are “destabilizing” natural grasslands, reducing diversity and making the ecosystems they support more vulnerable.
Additional nutrients flowing into the ground, the team discovered, synchronize the growth of different grass species, reducing what is known as the “portfolio effect.”
“If you have money in two investments and they’re both stocks, they’re going to track each other, but if one is a stock and one is a bond, they’re going to respond differently to the overall economy and are more likely to balance each other,” explained Eric Seabloom, an associate professor at the University of Minnesota, which led the study.
The team, which included scientists from the University of Zurich in Switzerland and Oxford University in the United Kingdom, collected plants from sites around the world, then dried and weighed them to measure how many plants had grown there over time.
“It was really striking to see the relationship between diversity and stability,” said Yann Hautier, also an associate professor at the University of Minnesota.
As Andy Hector, of Oxford University said, “The results of our study emphasize that we need to consider not just how productive ecosystems are, but also how stable they are in the long-term, and how biodiversity is related to both aspects of ecosystem functioning.”
The findings were published in the journal Nature on Sunday.