The benefits of greenroofs include storm water management, reduction in heat island effect, increased life span of roof surfaces, reduction in heating and cooling costs for buildings and the creation of wildlife habitat. The levels of benefits vary depending on what type of greenroof is built but they are a positive regardless. Check out https://greenroofs.org/ for lots of great and more detailed information about greenroofs.
I bring this up because a couple days ago as I worked on the 19th floor terrace of one of my residential clients in Manhattan I experienced how even just a very small greenspace can be enough to provide a habitat for wildlife. As I was moving some outdoor furniture around, I was startled by a bird rocketing out of an umbrella pine just in front of my face. It was a Mourning Dove and at first seemed as stunned as I was if not injured. It gathered its wits and flew off the terrace, I assume to grab a slice at Rays. I wondered if there was a nest in the umbrella pine, which is sizable for a potted tree but nothing near what it could grow to if planted in the ground. I found something much more special than a nest.
I didn't want to get too close so as not to disturb them but I could see their bodies pulsating from their heartbeats. I was immediately worried I had scared the mother off for good or she was injured and these two newly hatched Mourning Doves would be left on their own to perish . I carried on with my work periodically checking to see if the mother had returned. It was a few hours but eventually she came back and took her place keeping them warm and safe.
I came to work on the same terrace the next day and was happy to find mama and her babies where I had left them. A bit later in the day the protective father showed up and stood perched on a nearby chair guarding his family, making sure I minded my own business.
It was a really cool thing to see this young family making a home under my umbrella pine, reminding me that not only am I making beautiful green spaces for my clients but creating habitat for the various living creatures we share this concrete jungle with.