Problems Defining Old Growth

Old-growth is difficult to define because of (Tyrell and others 1998, Giles 2000):

• Lack of consensus as to which forest types occur in an old-growth condition.
• Difficulty in choosing which attributes to use to characterize old growth.
• The variation that exists in species stature and spacing due to site conditions and elevation.
• Lack of available data about historic old-growth forests.
• Questionable representativeness of remnant old-growth example.
• Changes in forest structure due to altered disturbance regimes since European settlement.
• Influences of pollution, exotics, fragmentation, and extinctions.
• The need to move beyond the stand-level treatment to consider the landscape scale.
• Differences in forest characteristics due to geographic location, e.g., eastern versus western forests.
• Differences in land use history.
• Differences in management objectives.
• Differences in values attributed to old-growth forests.
• Altered disturbance regimes over the last 400 years have changed the bioclimatic background within which historical old-growth forests developed and may inhibit our ability to recreate that exact type of old-growth forest.
• Multiple governmental agencies, non-governmental interest groups, and different, conflicting, and unclear laws and regulations all contending for a definition of old-growth forests favorable for their own agendas.
• The political sensitivity and potential impact of any particular definition of old-growth.