  The contemporary forestry preoccupation with non-declining even-flow during
yield simulations detracts from more important questions about the constraints
that should bind the end of a simulation. Whilst long simulations help to
convey a sense of sustainability, they are inferior to stronger indicators such
as the optimal state and binding conditions at the end of a simulation.
Rigorous definitions of sustainability that constrain the terminal state should
allow flexibility in the planning horizon and relaxation of non-declining
even-flow, allowing both greater economic efficiency and better environmental
outcomes. Suitable definitions cannot be divorced from forest type and
management objectives, but should embrace concepts that ensure the anticipated
value of the next harvest, the continuity of growing stock, and in the case of
uneven-aged management, the adequacy of regeneration.
