What a nice paper! Not only did I learn more about different regions of Russia, but also it is a great resource when you want to get an overview in what various ways iNaturalist data are used in scientific publications and how to motivate people using the site.
In the course of reading this paper I also looked up some of the recent statistics, and there are two more iNat success stories I find worth mentioning:
South Africa surpassed 1 Million observations (next one would probably be NZ) and Australia has more than 1 Million Research Grade observations!