We have been managing a 1300 acre forest commercially for 30+ years.  We harvest and replant every year.  Have NEVER used chemicals to release seedlings. We, with the help of an excellent crew, use machetes to whack away the blackberries and other competing non-native vegetation annually. The crew is paid well and we have thriving stands of trees of many species, some of which have already provided us with with the financial reward of a successful commercial thinning. Everybody wins including the environment/forest ecosystem. The all important values of water, soil and air are protected.