The fully-stocked old growth stand in the southern portion of the reserve is almost pure white pine, with a few scattered red pine.
White pine in the north of the reserve are less numerous and are in mixedwood stands with black and white spruce, balsam fir, white birch, and trembling aspen.
A few black spruce stands occur in poorly drained depressions.
Dominant white pine in the southern portion of the reserve have many trees exceeding 1.0 m (3.3 ft) in diameter, are more than 40 m (131 ft) in height, and clear boles extand up to 18 to 21 m (59 to 69 ft).
These pines have developed in a dense stand and are not branchy trees found in open areass.
Trees range between 250 and 300 years of age.
Most of the large pines are similar in size indicating that this is an even-aged stand.
The role of fire in forest succession elsewhere in the Great Lakes-St.
Lawrence and Boreal Forest Regions suggests that this stand probably orginated following presettlement forest fires.
There are numerous standing snags and down trees usually caused by weakening of the bole by heart rot.
Such woody derbris provides habitats for a variety of plant, animal, and bird species.
Soils are developed on upland moraines, on boulder pavements located in drainways, and on peatlands.
Soils on broad uplands have loam to silt loam surface soils (upper 30-45 cm; 12-18 in) indicating possible wind-blown (loess) origin.
Site quality on the broad upland is excellent due to the deep, well-drained silty surface soils thus accounting for the dense shrub and herb-rich understorey, and the impressive tall trees with large diameters and long clear boles.
These moist, well-drained soil conditions also favour the occurrence of yellow birch and red maple - species common in hardwood forests of southern Ontario, northeastern Minnesota, and northern Michigan and Wisconsin.