Sourced from Denverite
In November, Denverites narrowly passed an ordinance that requires new, large buildings to include green space on their roofs. We’re always interested to explore Denver as an urban ecosystem, so we went asking some local experts: Will green roofs be good for animals?
The answer: It all depends on what you grow. Native animals generally need native plants to thrive. Plant the wrong thing, and you won’t be too helpful.
There is indeed a need.
To start, let’s narrow this down. There isn’t much chance that deer or urban bunnies will make their way onto green roofs, as cool as that would be. But birds and bugs could. As it happens, they’re both in need of a little support.
In December we explored how climate change and development have diminished resting places for birds traveling between Mexico and Canada in what is known as America’s “central flyway” for migration.
Last spring we followed bee guru Gregg McMahan around during swarm season. While he said longer warm seasons (due to climate change) might actually be good for the metro area’s 500-plus bee species, they’re going to need more food to make it through the year. As with birds, development has diminished many areas that once fostered bee food.
What’s it gonna be?
Green roof advocates are most interested in lowering energy use (to battle the “urban heat island” effect) and mitigating Denver’s air pollution problems. The ordinance does not dictate what kinds of plants go on roofs. As far as their primary goals go, any plants should do the trick. But when it comes to helping wildlife, what you plant is crucial.
Particularly, said Denver Museum of Nature and Science (DMNS) Senior Curator of Entomology Dr. Frank-Thorsten Krell, if you want to help native species, you’ve got to grow native plants.