Landscape Scale Approach to Old Growth Restoration

Trombulak (1996) proposed some general principles for planning a landscape-scale approach for old-growth restoration and maintenance:

• Small preserves are more vulnerable to destruction than large ones.  Natural disturbances from wind, fire, and disease are more likely to destroy 10-20 ha stands than 100 + ha stands.
• Old-growth restoration strategies should de-emphasize goals which aim for a specific set of species as an end point because of the natural unpredictability in patterns of species colonization and establishment as well as the impact of anticipated climate change.
• Old-growth restoration plans should apply to the long term-- to centuries.  Long-lived individual trees take centuries to develop old growth characteristics.  In addition, the abiotic and biotic environment in which these trees live also requires these centuries to fully develop into an old-growth community.
• Old-growth restoration efforts should focus on the old growth community complex rather than on a few of its elements in isolation. Old growth restoration may require active management until the conditions for the successful functioning of natural regeneration have been established.  Common impacts that might prevent old-growth from successfully regenerating include: eroded soils, unnaturally high populations of herbivores (deer or domestic animals), exotic plant competitors, exotic insect pests and pathogens, fire suppression and timber harvesting practices that increase the threat to old growth from any of these factors.
• A landscape restoration plan must include an design for human use of the old-growth landscape.  Permissible, as well as prohibited uses, must be clearly spelled out.
• A professionally responsible old-growth restoration plan will avoid questionable practices, which, upon careful examination, fail to bring about the true goal.  Some questionable practices are (Trombulak 1996):
  • Selecting stands for old-growth restoration because they are economically unsuitable for timber harvesting.
  • Selecting primarily recently clearcut or other heavily modified stands for the restoration program when other choices are available.  These types of stands will take so long to develop old-growth characteristics that the plan effectively excludes old-growth from a landscape for centuries to come.
  • Selecting small, widely scattered stands for old-growth restoration.  These isolated patches often have too large a probability distructive disturbance events to ever make it to old-growth status.

Major challenges related to planning at the landscape scale are: (1) deciding which areas we are going to protect and, (2) deciding which of the selected areas are going to be managed by passive restoration and which by active restoration.