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Sample experimental sites

Alternatives to clear cutting – White pine ecosystem study area – Fuelwood road genetics plantation area – Old-growth eastern white pine

To better understand some of the activities at the Petawawa Research Forest (PRF), the following examples provide a snapshot of some of the experiments undertaken:

Alternatives to clearcutting (partial cutting of white pine–red pine over 80 years)

The PRF is the home of Canada's oldest forest research plot, permanent sample plot (PSP) 1, which is situated in a 40-year-old eastern white pine–red pine stand. Since its establishment in 1918, PSP 1 has been selectively harvested six times, providing solid scientific data on the long-term sustainable management of this ecotype. For comparison, the control plot in the same stand, PSP 2, has never been cut. Although results were recently published in the Forestry Chronicle 74(4): 606-616, other ecological comparisons remain to be done.

White pine ecosystem study area (Meridian Road Silviculture Area)

In 1994, 48 plots were established in a 27-ha experimental area to evaluate silvicultural practices that integrate shelterwood harvesting and site preparation in an environmentally acceptable and sustainable manner. A four-replicate randomized block split-plot design is being used on the plots. Testing involves three crown spacings (two crowns, one crown, a control) and five site-preparation treatments (prescribed burning, mechanical, chemical, mechanical-chemical, no treatment) with and without underplanting. During the growing season, a series of data loggers monitors environmental conditions such as temperature, humidity, soil moisture, precipitation, and light. Survival, growth, physiological responses (such as allocation of biomass), chemical composition, and morphology are measured in naturally occurring and planted seedlings. Surveys to characterize the shrub and herb layer are conducted. Crown development and growth response of residual trees are monitored.

Fuelwood Road genetics plantation area (Plantation Area 114)

The PRF is home to several hundred genetic studies. The largest plantation area in the tree genetics and breeding program occupies 22 ha. Since 1957, 46 trials have been established. The majority of plantations involve provenance and progeny tests of Norway spruce, white spruce, and non-native larches, such as European larch. Smaller plantations include many non-native spruces, pines, and birches. These genetics plantations offer today's researcher the opportunity to test variables, such as climatic conditions, on trees with known genetic origin.

Old-growth eastern white pine (Natural Area 1)

Natural areas are ecological reserves that are studied. Natural Area 1 has old-growth characteristics including large-diameter trees, large-cavity trees, coarse woody debris, and mound-pit microtopography. This area was established to study succession patterns on a productive, moderately dry site. The stand was first measured in 1948; repeated measurements followed over the years. The last recorded disturbance of the stand appears to be a release (of the understory) in the 1880s either from harvesting or blowdown. Towering eastern white pines, many 165 years old, are abundant throughout the site. Shade-tolerant hardwood tree species such as sugar maple dominate the understory and will eventually displace the pine in the absence of fire or other significant disturbance. At this point, however, the impressive white pines are among the largest at the PRF and share the canopy mainly with sugar maple and scatterings of white ash and basswood. Red oak, ironwood, white birch, and red maple make up a minor component of the stand overstory.