“In Defense of Plants” podcast on Urban Ecology

Today I listened for the first time to the In Defense of Plants podcast. I have been looking for good podcasts on urban ecology, so I checked out Episode #14 (Urban Ecology!).

In this episode, host Matt interviews Dave Spiering of the Tifft Nature Center in the City of Buffalo. Spiering discusses about how urban brownfield recovery can be understood as a successional process, and what that means for our efforts to re-wild urban areas. Tifft seems interesting, as it is a nature center built on top of a brownfield. As such, its success depends on restoration rather than simply preservation.

Spiering has a lot of interesting things to say about the challenges that urban ecological restorationists face. The prevalence of invasive species and the relative isolation of urban sites from native plant sources are chief among concerns. Invasive plants are pretty ubiquitous, and it is easy to “recover” a site by allowing non-native species to take over. But as Spiering explains, what happens early in a site can dictate where succession takes that site, and simply living with invasives may mean living without the eventual ecological community we want to see at a site.

The isolation of these sites can also be a problem, as Spiering explained that seed dispersal is pretty limited in urban areas, especially to sites that don’t have vegetation in place to attract birds. In some cases a recovering area may have a seed bank in the soil that’s just waiting to explode under the right conditions, but more often seeds need to be imported in order to allow re-establishment of native vegetation.

This episode also has some really interesting discussion of whether urban sites are unique and require specific ecological theory to explain their dynamics. Spiering thinks that the basic laws of ecology still apply in urban areas, but these areas tend to have different dynamics because of different initial conditions and overall species availability. He had some interesting things to say about succession: that as they re-wild, many urban sites sit somewhere between primary and secondary successional processes. While most sites are not bare rock, they sometimes resemble bare rock in the sense that their soils are toxic or otherwise unsuitable for initial colonization. On the other hand, many urban sites maintain a strong base of soil, soil that is just waiting for the right dispersed seeds to take hold.

Spiering favors early intervention rather than long-term sustained manipulation as a means of achieving our restoration goals. As he explained, how a restoring site initially is populated by plants pretty much defines where it can go.

There’s a general attitude these days that trying to restore ecosystems to their native states is a fool’s errand, but Spiering pushed back a bit on this idea. While he didn’t advocate a purist-native approach to restoration, he cautioned against “always throwing in the towel” because allowing invasives to dominate really limits what a restored site can become.

A funny aside in this episode discusses beavers and deer, two species that are quickly becoming unwelcome byproducts of urban re-wilding. Spiering pointed out how restored woodlots are a lot harder to manage than fields because of the dual impact of beavers (on mature trees) and deer (on seedlings). I am not holding my breath to see beavers or deer anywhere in Brooklyn… but maybe I will be surprised!

I was excited to discover this really informative podcast; it’s accessible enough for non-botanists like myself but still very rich in information and ideas.