WSC investigates ecosystem services in the city
Post by Carly Ziter
I’m a little nervous, as I stand on the porch preparing to ring the doorbell of a stranger’s home. After all, it’s not every day that someone you’ve never met comes a-knocking, asking to take soil samples from your front lawn. Luckily for me, many Madisonians are kindly willing to part with a sliver of their yard in the name of science–or at least, so I’m told, since this is the first of many doorbells I’ll ring this summer.
Armed with my notebook and my trusty soil-corer, I reflect on how different this residential neighborhood is compared to the fields and forests I’m accustomed to working in. Certainly, when I imagined my future as a field ecologist, I didn’t picture that I’d be asking permission of my neighbors to dig up their yards! But the soil samples I collect this summer will contribute to a new Water Sustainability and Climate study of Madison’s urban ecology.
The parts of the city I’m most interested in are its green spaces. Green spaces not only make the city more enjoyable, they provide benefits for our health and safety. From the UW arboretum to city parks and residential lawns, green spaces help reduce Madison’s urban heat island, the warmer temperatures felt in cities. They also offer permeable surfaces in an area dominated by concrete. This allows rain to filter into the soil, lessening the risk of flooding. The soils under our feet play a role in the climate system, too, storing carbon that would otherwise add to a warming climate.
But not all green spaces are equal when it comes to providing these natural benefits, also known as ecosystem services. Just as architecture trends reflect the past, urban ecology is also shaped by what came before.
Soils, for example, change very slowly over time, and impacts of past land use–such as the loss of topsoil that happens over years of farming or the disruption that occurs during construction projects–can sometimes last for decades after development. In a previously farmed area such as Madison, these land-use legacies may mean that soils in older neighborhoods have had more time to rebuild than in new developments. Because older soils often have higher amounts of organic matter, or the layer of soil responsible for sucking up water like a sponge and storing carbon, older developments might have less runoff during storms and help us combat climate change.
We can’t change the past. So what can today’s urbanites do to encourage ecosystem services in the city?
One option individuals have is that classic planet-friendly action: plant a tree. You could also install a rain garden.
However, whether these simple management actions can make a dent compared to larger forces like history isn’t well understood. Can we really combat the effect of the “urban jungle’s” parking lots by amping up the benefits of its parks? Sampling soil in different areas of the city will allow us to start to tackle these questions, and to learn which types of green space are benefiting us most and why. With 8 out of 10 Americans living in urban areas, this type of “backyard science” is increasingly important if we want to create more resilient cities.
By influencing soil characteristics, the past may exert control over present-day ecosystem services. Through my work this summer, I hope to start untangling the question of how strong this role of history is, and whether it’s greater than the impact we can have today by managing the urban landscape.
And if I show up at your door later this month, I hope you’ll help me out in this quest!