Revisiting 100-year-old Research Plots By Steve D’Eon, Renfrew and County Chapter • steve.deon@canada.ca
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t the Canadian Forest Service’s Petawawa Research Forest (PRF) some of the 200+ Permanent Sample Plots (PSPs) have been continuously monitored and measured for 100 years. These centurions have recorded a century of forest processes, growth, mortality, and management impacts. PSP001 is the oldest continuously monitored forest research plot in Canada (Figure 1).
Figure 1: PSP001, established in 1918, was part of the Canadian Institute of Forestry 2019 Annual General Meeting field tour.
Since 1918 the methodology to establish a PSP has remained the same. A plot is carefully laid out on the forest floor, corner posts are hammered in, and each tree is tagged, measured, and mapped (Figure 2). a
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Pencils and paper were the tools of the trade during this era. The original tally sheets, the paper now brittle and showing its age, have survived multiple trips out to the bush (Figure 3). As the PSP series grew upkeep of plot infrastructure, as well as periodic measurements, became a right-of-passage for students at Petawawa each summer.
Figure 3: PSP007 tally sheet dated July 10, 1919.
Thinking back, one realizes measurements made in 1918 and 1919 took place during the Spanish flu pandemic. It was a bit ironic for me to join the PRF’s Melissa Vekeman and Céline Lafrance measuring some centurions this fall; 2020 being during the COVID 19 pandemic. Pandemic aside, it was exciting as we socially distanced our way across a couple of plots using the data to track 100 years of growth and survival of individual trees (Figure 4).
Figure 2: a) corner post for PSP010. b) Tree 098’s new tag with the older tag grown over. c) Map of PSP016, 1920. d) numbering trees on a PSP, 1919.
The Ontario Woodlander—An Ontario Woodlot Association Quarterly. Issue 102, March 2021
Figure 4: Left) measuring the current diameter of PSP016 tree number 410. Right) indicating the 1926 diameter (9.1 cm dbh) of PSP016 tree number 140.
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