There are many kinds of rå in the Scandinavian folklore, where Skogsrå (forest) is one of them. There is also the Sjörå (sea or freshwater), Havsrå (ocean or saltwater), Bergsrå (mountain) as well as human constructions such as Skeppsrå (ship or boat) and Gruvrå (mine). Some even consider Gårdstomten as an rå, often called Gårdsrå (farm) in those cases.
The word rå comes from the belief these beings are considered to protect certain areas or construction and the best translation might be warden or keeper. The word itself is closely related to the word råda, which translates to advise or reign. Also, the word rår which translates into controlling something.
This leads to the conclusion that these beings have certain control of the animals and the environment in their area. They can both help and cause trouble for all those that enter their domain. Many that have an rå close by, be it on their farm or while working in the forest as a hunter or woodworker, tries to stay on the areas rå good side. This can lead to help in their field while ignoring them or to make them angry causes trouble.
An interesting thing to consider is that nature is more often presented as female, while manmade constructions are presented as male. It’s not always the case, but it is a trend among the story.