There was a fascinating article this week out of the horticulture school at Lullier Switzerland that doesn’t appear to be about beavers at all. Young scientist Beat Oertli is earning his degree by studying something we all take for granted. His thoughtful work is entirely based on data collection and other scientific things that make your eyes tired.

The funny thing for us, of course, is that it is ENTIRELY about beavers. We know better.

Why small ponds have enormous value

Ponds may not seem as glamorous as rushing rivers or majestic lakes, but they’re indispensable when it comes to biodiversity and ecosystem health. In Switzerland natural ponds have all but vanished with the rise of agricultural intensification.

It turns out that water purification and filtration is just one item on a very long list of services that ponds provide, both for humans and the environment. These services range from flood and erosion prevention, to habitat for endangered species – even absorption of the greenhouse gas carbon dioxide.

“We’ve estimated that one pond can trap as much carbon as one car produces in a year,” Oertli says.

But he explains that these services are in danger of disappearing: over the last 200 years, 90% of ponds and small pools in Switzerland have dried up or been destroyed, largely as a direct result of human activities and agricultural intensification.

It’s easy to underestimate the environmental contribution of ponds, given their small size compared to larger freshwater resources like lakes and rivers. But as Oertli explains, their greatest ecological benefits are realised on a collective level, as each small body of water plays a key role in a larger network.

“In a region, if you put all the biodiversity of small ponds together, it’s many more species than lakes and rivers. That’s because ponds are all very different – they are like humans: you cannot find two that are the same.”

And it’s not just frogs that love to call Swiss ponds home: they are also crucial habitat for a variety of plants and fish, as well as beavers, shrews, voles, bats, leeches, dragonflies, and pollinators like bees and syrphid fliesexternal link.

Hurray for the small ponds!  These little saucers of nature scattered across our landscape should be added together to count their contributions, Oertli, you’re onto something! But did you just say that ponds are crucial to beavers?  I admit I don’t know anything about the Swiss language but I think you got your sentence structure reversed,

Beavers are crucial to ponds.

But individual ponds are valuable as well, especially in an urban setting, which is the focus of Oertli’s research in Lullier. Even an artificial pond in the middle of a city can host natural biodiversity, as well as provide key services for humans. 

“Urbanisation is increasing, and ponds are a good example of systems that provide a lot of services for landscaping, flood protection, education for students and children, for trapping pollutants and purifying waters that flow through the city,” Oertli explains. He adds that urban ponds can even provide a crucial reservoir for irrigating parks and gardens, and even for fighting fires.

You don’t say. Ponds are important in cities? They provide a place for trapping pollutants and purifying water and even make a reservoir for fighting fires? Allow me to repeat that paragraph by adding an overlooked word to your sentence for clarification.

BEAVER ponds are a good example of systems that provide a lot of services for landscaping, flood protection, education for students and children, trapping pollutants and purifying the waters that flow through the city.

Well said, Oertli, I literally could not agree more.

You know I saw something recently that reminds me of this, you would think everyone would be lining up to get beaver ponds in their city, wouldn’t you?

Researchers find urban development dramatically increases stream flow