Isn't that needed only if you are being paid?
Good question that I’m not 100% sure of. I think whether you are paid or not, you are just as capable of hurting/killing yourself or another. The difference is that if you are trained and licensed, those eventualities are reduced. You are also likely to have the correct liability insurance. Pretty certain the landowner (who is also liable for any accidents etc) wouldn’t be up for an unticketed operative to do any work on their land. That said, it happens near me all the time. A tree barely hits the floor and it has been processed and already seasoning for next year’s fires.
The only unpaid work I do is volunteer work for Sustrans. I am a trained operative though. Weirdly a local council refused to let me do leaf clearance on one of their shared paths last year because I wasn’t a council employee so I guess they felt I wasn’t covered by their liability insurance. Despite offering to clear the ludicrously dangerous road chutney for free. Red tape gone mad. This year I’ll probably just go ahead and clear the path when it is quiet.
Could the OP use a bow saw near the public path (with permission from the landowner) and then a chainsaw at home?