>>2610053tree planting probably not.
felling and related work, probably yes. however running a saw for years without supplementary lifting has given me very disproportionate muscles (ie my left bicep/delt are considerably longer/larger than my right) and it fucks with my coordination a bit. but in terms of pain, nah
ive considered starting a similar business but just doing defensible space work for boomers with their 3rd 10,000 sqft home in fire prone areas