My philosophy is simply this: if I can maintain an ever-increasing timber inventory (up to some predetermined maximum yield), the the related forest values of wildlife, watershed, recreation and aesthetics will also have the basis to be sustained.
    This involves establishing a long-range sustained yield goal and then managing the stand to realize this goal.  In a nutshell, management involves two components: Increasing inventory ( a quantitative goal) and improving stand structure ( a qualitative goal).
    Inventory is increased simply by cutting less that the forest is growing, until the sustained yield goal is attained.  For example, if, during a 15 year cycle, a property grows  1 million board-feet, then a harvest of 600,000 board feet will allow the remaining 400,000 board-feet to be added to the future growing stock.
    By repeating this pattern over several cycles, I can continually build stand inventory and eventually attain the long term sustainable harvest level or "allowable cut."  Once the allowable cut is attained, I can harvest the periodic growth without ever depleting the inventory.
    I like to view the forest inventory as principal and the annual growth as interest earned on the principal.  The essence of a sustainable forest is the ability to continually harvest the interest without having to touch the principal.
    This concept is best illustrated by one property which has been under sustained yield management for 25 years.  The volume is almost triple what it was in 1972.  Over this period, we have harvested significantly more timber than was present when management began in 1972.
    However, establishing a sustained allowable harvest only addresses how much volume is cut.  It does not consider which trees are removed or what the forest will look like following harvest.  It is essential to retain the biggest, best quality and most vigorous trees in the post harvest stand to build future inventory.
    Thus, in developing the sustained yield forest, it is important not only to cut less than the periodic growth, but equally important to refrain from cutting the best trees.  My personal criteria for tree removal can be lumped into three strategies:
    1.  First, mark the damaged, dying or diseased trees.  These are generally trees which will die before the next harvest.  (I make exceptions for trees I'm leaving to turn into snags)  This is a "sanitation" strategy.
    2.  Second, mark suppressed and intermediate crown class trees.  These are trees which are not contributing growth to the stand, nor will they be expected to do so over the next cycle.  This is a "thinning from below" strategy.
    3.  Lastly, mark larger trees which improve spacing for the high-quality "crop" trees which will be retained.  This is a "spacing improvement" strategy.
   
    In general, I try to use each harvest as an opportunity to upgrade overall stand quality by choosing which trees I leave and how they are spaced.
    In this way, I may initially enter a stand as early as 35 years old in a commercial thinning, and return two, three or more times until the stand is more than 80 years old and target diameters of 26 to 40 inches have developed.  I like to favor redwood, but not to the exclusion o f all other species; I seek a natural ecological balance and biological diversity.
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