Wildlife habitat in roof gardens

[Barbara Peterson]

I was reading about a roof garden in an l.a. magazine and noted that among the benefits was that “the gardens provide a habitat for local wildlife”. I checked the plants listed in the article and, yes, they can provide shelter and nectar for birds and insects…wildlife…and on this project, there was a fountain (water).  But the roof gardens that I have seen in magazines which state that they “provide wildlife habitat” are located on the 8th and 9th stories and some above that.  And they tend to be located in dense urban areas with no other roof gardens nearby but where some street-level planting may be seen.

Habitat is defined by the US Fish & Wildlife as “a combination of environmental factors that provides food,           water, cover and space that a living thing needs to survive and reproduce”.

I do not wish to downplay there importance roof gardens – I do think that they are relavent –  and yes, ‘you have to start somewhere’ but here is my question: has anyone done any research (or seen any) to see how long it takes for wildlife to begin utilizing the gardens and what types of wildlife actually utilize roof gardens.  I’m particularly interested in those roof gardens which are located in that 8 story range and above.

[Roland Beinert]

I am not sure there is any research that answers your specific question about how long it takes. The journal Urban Ecosystems is always a good source for information on this sort of thing. They did an entire issue on green roof ecology in 2008, although I cannot guarantee they addressed your question in that issue. I imagine they have also done a few other articles on green roofs since then. As with most urban ecosystems, we probably are talking about the most adaptive and mobile of species, even if they are rare. Mostly birds and insects. It may happen faster than you think, simply because we are talking about the most mobile species.

[Tosh K]

Must be a dissertation topic somewhere… very good question.  We’ve done a lot of greenroofs but not a whole lot of post occupancy research.

KieranTimberlake (architects) have done some research on plant distribution on their roofs (at construction and few years later to compare strengths and migration) – their research division might be looking at this?

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