32 years in the business.
It's not either/or. Depends upon site conditions and objectives. Sometimes a combination of both is needed. Time of year is also a factor. Different results depending upon Spring versus Fall burns (Locally, Summer is too dry/too risky, and Winter is too wet -- cannot burn snow.)
Burns require optimum weather conditions. The right combination of fuel moistures, humidity, and wind speed/direction. Then they all have to occur on an allowable burn day under local air quality rules. One burn I was involved with waited three years for the perfect alignment of conditions and air quality rules. But that was unusual. One northern California National Forest looked at historical climate patterns and allowable burn days under Air Quality rules and found they averaged 18 days per year for optimum weather conditions and air quality regs. Cannot have much of a prescribed burning program with 18 days per year.
Mechanical treatment can be done any time. Not weather dependent. Some areas may need some mechanical treatment before it can be safely burned with satisfactory results. Other cases, mechanical treatment will not achieve the desired results -- only fire will produce the results wanted.
