A new study published this week and led by a Bard College biology professor shows catastrophic flooding can be mitigated by protecting biodiversity. WAMC’s Hudson Valley Bureau Chief Allison Dunne spoke with the lead author, who says though the flooding was studied in Germany, there could be comparisons to the Hudson Valley.
In June 2013 a 200-year flood hit much of eastern and central Europe. Flooding in Germany covered multiple river basins, including, in central Germany, the location of one of the longest-running biodiversity experiments in the world. Because of the longstanding experiment, the ability to research flooding’s impact on an ecosystem was happenstance. Dr. Alexandra Wright is the lead author of a study that researched the flooding impacts.
“So the biggest thing I would say is that this is the first time ever that we’ve had any data about the role of biodiversity during flooding.”
She says she expected to find a devastated ecosystem. The results surprised her.
“In many cases there was a positive response to the flood.”
Wright says lots of species, or an ecosystem with high diversity, require a large amount of resources to keep going, and that’s exactly what the flood provided, and quickly. First, it provided a lot of water.
“It also kind of jumpstarted the nitrogen cycle is what it looks like. So the water came in. A lot of biomass did die, so a lot of plants did die in the very, very short term,” Wright says. “But with all that moisture and all the heat from the summer, all of the dead biomass recycled into available nitrogen, is what we think happened, very, very quickly.”
She says with more water and more nitrogen, the high diversity ecosystem rebounded well. Wright says in the absence of any other such data, the study is widely applicable, especially for a region like the Hudson Valley, which is similar in climate and topography to the experiment site in Germany, also a river valley.
“What you can take from this in terms of anywhere in the world where you see big floods is that if we can maintain biodiversity at really high levels, the ecological systems are going to recover very fast and you may even experience causative effects,” says Wright. “And in most urban areas, we aren’t doing a great job protecting biodiversity.”
Portions of the Hudson Valley saw major flooding from Hurricanes Sandy and Irene and Tropical Storm Lee. Wright points out that in the next 100 years, rising atmospheric carbon dioxide concentrations are predicted to increase the frequency and severity of extreme weather. She says mitigating the costs of floods not only in Europe, but elsewhere in the world, will depend on the ability to maintain high-diversity ecosystems. And based on the results of this latest research, Wright says it seems that extreme floods could temporarily increase productivity in areas where biodiversity has been protected.
Wright, a biology professor at Annandale-on-Hudson-based Bard College, says she would like to further study species’ ability to rebound and adapt to catastrophe, among other topics.
“One of the things I’d like to do is to think about other disturbances that potentially have similar effects in that they result in a large increase in resources. And a fire could likely have a similar type of effect,” says Wright. “With a fire you have a huge influx of light and you would have a huge influx of nitrogen because all of a sudden you have all this available nitrogen in all this burned material.”
The study was published in the journal Nature Communications.
