The goal to regenerate paper birch was a success in treatment area 1 where paper birch regenerated at 3,556 stems per acre and 100% stocking (Table 2). Northern red oak also regenerated well at 822 stems per acre and 100% stocking. Maple regenerated at 867 stems per acre in treatment 1.
Treatment area 2 seemingly had too much residual crown cover and competition by sedges and ferns for birch to propagate and favored regeneration of shade tolerant sugar maple at 500 stems per acre, northern red oak at 150 stems per acre, and paper birch at 50 stems per acre.
Treatment area 3 (control) was dominated by trembling aspen at 4357 stems per acre but also had regeneration of birch, oak, maple, and ash.
All objectives of the site prep were met. Mineral soil was exposed enough for birch to germinate. The overwood provided enough light for germination and growth of shade intolerant birch and oak but allowed enough precipitation in and buffered drying of the seedbed. Aspen was set back enough for paper birch to establish, but still remains a component in the stand. Very little root damage or dieback was observed on residual timber due to an optimal shallow trenching job. Even though no birch seed trees were left, birch seed rain from adjacent stands was adequate.
Table 2. Regeneration results by treatment and species. Values are stems per acre.
||Northern red oak
|1) Shelterwood, residual basal area 36 ft2/ac, double disc-trench
|2) Shelterwood, residual basal area 75 ft2/ac, double disc-trench
|3) Clearcut, no disc-trench (control)