To me the problem with police is that they protect private property. Private property is a network of oppressive systems that all work to hurt the average schmuck and nature for the benefit of someone enclosing the commons.
Rangers still have arrest power and can put you in that prison system I oppose, but they aren't protecting private property. They're protecting the commons. I don't want poachers on public lands because they degrade the ecosystems that provide for me and protect me. I don't want people defacing national parks because those belong to the public a century from now. I don't want people dumping shit or camping irresponsibly in national forests because wildfires impact the entire community for generations. Littering in parks hurts everyone and everything encountering it while breeding the pests that spread disease.
Those are crimes against everyone who does or will exist. Environmental crimes and ecocide need to be regulated. Public land needs to be protected or the private businesses that pigs protect will clear cut the forests and destroy the rivers like they did before the rangers.