Active Management for Old Growth Restoration

Old growth definitions based on structural characteristics of forests imply that silvicultural techniques can be used to actively create or maintain these old-growth conditions (Tyrell and others 1998):

"Silvicultural manipulations can indeed create or accelerate the formation of some of the structural attributes of old-growth (Nyland 1997): produce large trees through crown release (see also Goodburn and Lorimer 1997, Singer and Lorimer 1997), maintain an irregular upper canopy, increase vertical structural diversity, create snags, mimic gap dynamics (see also Runkle 1991), and increase age diversity. Other practices, such as adding nest boxes or dead logs, provide habitat associated with old-growth (Runkle 1991). However, some old-growth characteristics prevail only with sufficient time. For example, it takes time for abundant coarse woody debris to develop even with silvicultural manipulations (Goodburn and Lorimer 1997), and for logs to reach advanced stages of decay (Tyrrell and Crow 1994)."

Many silvicultural practices might be used in an active old-growth restoration project (Trombulak 1996, Giles 2000):

• Removal of exotic species.
• Thinning selectively to restore natural species composition and increase individual tree sizes more rapidly.
• Prescribed burning to mimic wildfires.
• Selectively harvesting trees to create clearings and open gaps in the canopy.
• Extending rotation ages.
• Re-introducing wildlife flora and fauna known to be historically present but currently absent.
• Creating standing snags.
• Re-introducing of organic log structures to streams.
• Excluding horses.
• Managing of populations of herbivores, such as deer.
• Identifying and eliminate vectors for the introduction of exotic plants.
• Managing local fish populations.

The active application of silvicultural methods to restore old-growth forest conditions is controversial and still largely experimental (Trombulak 1996). The controversy centers on the contention that silvicultural management techniques do not produce the full array of old-growth characteristics and do not, therefore, result in old-growth (Leverett 1996). Therefore, until we improve our knowledge and predictive capabilities, Trombulak (1996) advises that active management for old-growth restoration should be limited to small fractions of an entire restoration project. The results should be monitored and analyzed and management should be altered on the basis of analysis (Trombulak 1996).