Thanks. Property boundary lines are often painted here but no much else.
We use flagging tape, some use plastic but the company I work for uses tape made of paper, it can even be boiled with the pulp without harming the process, unlike plastic.
Seed trees are left to the harvester operator to choose, but usually we do clear cuts and replant the following year.
We flag boundaries, marches/creeks and sometimes the path we wish the forwarder to use to get most of the wood out to the landing, that's mostly to guide them around wet areas where they can get stuck or damage water ways or to show a way through rough terrain etc.
So our flagging is to show where to cut but it's up to the logger or operator to choose which trees to cut and which to save.