Peterborough Old-Growth Forest Project - Level 1

Help us discover old-growth forests in Peterborough County with a few pictures and tree trunk measurements!

Tree species to look for: eastern hemlock, white pine, American beech, and white cedar trees can live to be many hundreds of years old. But other species can grow to be really old too, if conditions are right!

Measuring tree trunks: measure the diameter/circumference of a tree trunk at breast height (4.5 feet) and make sure it meets the "minimum old-growth size" for the species - a list of sizes is included below. We recommend taking a screenshot of this for easy access. A flexible measuring tape can be used to measure circumference at breast height (CBH); a DBH tape, calipers, or meter stick can be used to measure diameter at breast height (DBH).

One more thing we're interested in is dead trees in the form of stumps and snags (dead standing trees). This gives us a sense of what major disturbances have occurred the forest.

Surveyors should document as many of the biggest trees in the stand as possible.

Want to do more? Check out our more advanced data collection protocols at https://www.peterborougholdgrowth.ca/our-protocols

Minimum old-growth size (diameter/circumference, in cm):

15/47 - Black Spruce (Swamps)

25/79 - Jack Pine, Tamarack

30/94 - White Cedar, White Spruce, American Beech, Black Spruce (Uplands), Balsam Fir

35/110 - Red Maple, Sugar Maple, White Birch

40/126 - Eastern Hemlock, Poplar, Red Pine, White Oak, Bur Oak

45/141 - Yellow Birch

50/157 - Black Cherry, Eastern White Pine, Red Oak, Black Ash, White Ash

60/188 - Silver Maple, American Basswood less ↑