People say that people who ignore history are doomed to repeat it. It turns out there’s another reason not to ignore history, according to a new Michigan State University study published in the journal Ecology.
When it comes to restoring ecosystems to their natural state, humans cannot ignore history if they want to replicate successful efforts.
“Restoration is notorious for producing different results with very similar approaches,” said Chris Katana, a research associate in MSU’s Department of Plant Biology and first author of the new report. “There’s a lot of variability.”
Catano works with Lars Brudvig, a professor in the College of Natural Sciences. One project in Brudwig’s lab is looking at the main factors that contribute to this variability. Supported by the National Science Foundation, this new research focuses on one of those factors — when a site recovers — through the lens of biodiversity.
“We see that the past matters. History matters,” Catano said.
Working on a site that was once an active airstrip, the team restored 18 plots of prairie. The researchers kept all restoration conditions the same as possible, except when the restoration began.
They then tracked how different communities of organisms came together at those sites—for example, what kinds of plants grew and what other organisms they attracted. In addition to characterizing the biodiversity, the team also analyzed how it affects the site’s downstream ecological functions.
“It’s been a huge question in ecology for almost 30 years to understand what the consequences of biodiversity are on how an ecosystem functions,” said Brudwig, who is also a core faculty member in the Ecology, Evolution and Behavior program. EEB, at MSU.
Somewhat surprisingly, greater biodiversity did not always translate into a more functional ecosystem in the team’s experiment.
There is a lot of evidence supporting a positive relationship between biodiversity and ecosystem function, but many of these studies have been conducted under highly controlled conditions, the team said. With its unique site designed specifically to study the effects of history, the team noticed that relationships are more complex in a more natural environment.
“We saw relationships that ranged from positive to neutral to negative,” Brudwig said. “In nature, the results are a huge mixed bag.”
Brudvig emphasized that this work does not overturn previous findings or deny the conclusion that, generally speaking, more biodiversity is a good thing. However, in individual cases, Brudwig’s team shows that biodiversity impacts are subtle and complex – they cannot be summed up by a single value or measured quantity.
“There is no number for biodiversity that tells you the whole story,” Catano said. “In this case, it is the identity of the keystone species and their traits that are hidden behind the numbers that really matter to the functioning of ecosystems.”