What's notable about this is not that they're mapping the trees - that was going to happen. What's notable about this is the openness, the volunteer effort, and

What's notable about this is not that they're mapping the trees - that was going to happen. What's notable about this is the openness, the volunteer effort, and possibly the quality of the data and relatively low cost due to that volunteer effort. This may also have started out seeded with data from aerial photography - possibly with pretty good data on tree types and rough sizes which could be gathered from color data particularly if they used several seasons of data. Mapping of trees was going to be done by whoever was responsible for maintaining them, on a smaller basis by anyone required to work around them (say for sidewalk work), and probably by multiple other organizations.