Rotation length runs from 3-5 years for willow to 15-25 for oak, and it decides the size of what you cut: on the parent article’s yields, a willow stool gives about 4-7.5 kg at each cut and an oak stool about 96-160 kg. Short cycles mean many light stems and quick drying, long cycles mean few heavy stems, and cutting too soon or too late each weakens the stools.
Part of Coppicing & Fuel Management
Choosing a cutting cycle for each coppice species, and what the choice means for the size of stems, the work per stool and the health of the stools.
Rotation By Species
From the parent article, in years: willow 3-5, poplar and aspen 3-5, alder 5-8, hazel 7-10, birch 8-12, ash 10-15, sweet chestnut 10-15, beech 15-20, hornbeam 15-20, oak 15-25. Within a range, the shorter end gives thinner wood sooner and the longer end heavier wood later.
What A Cycle Costs In Work
Wood per stool per cut = yield per hectare per year × rotation ÷ stools per hectare. Using the parent’s yields (willow 8-15 t/ha/yr at 5 years, hazel 3-5 at 8, ash 4-7 at 12, oak 3-5 at 20) and its planting densities (10,000, 2,500, 1,100 and 625 stools per hectare):
| Species | Wood per hectare per cut | Per stool per cut |
|---|---|---|
| Willow | 8 × 5 = 40 to 15 × 5 = 75 t | 40,000 ÷ 10,000 = 4.0 to 75,000 ÷ 10,000 = 7.5 kg |
| Hazel | 3 × 8 = 24 to 5 × 8 = 40 t | 24,000 ÷ 2,500 = 9.6 to 40,000 ÷ 2,500 = 16 kg |
| Ash | 4 × 12 = 48 to 7 × 12 = 84 t | 48,000 ÷ 1,100 = 44 to 84,000 ÷ 1,100 = 76 kg |
| Oak | 3 × 20 = 60 to 5 × 20 = 100 t | 60,000 ÷ 625 = 96 to 100,000 ÷ 625 = 160 kg |
These use the planting densities as the number of stools, which may overstate stools in a mature wood where some have died, so the weights per stool may be higher in practice. The basis of the parent’s tonnes (green, air-dried or oven-dry) is not stated.
The tool follows from the load: a willow stool is cut with a billhook or a light saw; an oak stool needs a saw and an axe and the stems must be lowered with care.
Failure Modes
- Cutting too early. The stool has not rebuilt its reserves (see Biology of Regrowth) and sprouts weakly or dies.
- Cutting too late. The stems are heavy, shade the stool and are hard to handle; the stool can fail when finally cut.
- Uneven cutting. If the cycle slips, coupes get out of step and the yearly supply swings.
Method: Matching Cycle To Use
Step 1: Decide the size of wood you want. The corpus rocket stove article uses dry sticks 1-3 cm thick, 20-30 cm long (Fuel & Operation), which short-cycle hazel or willow supplies. Heating logs suit longer cycles.
Step 2: Pick the rotation within the species’ range.
Step 3: Record the actual yield at each cut and adjust.
Common Mistakes
- Using one rotation for all species. Each species has its own.
- Extending the cycle “to get more wood”. Past the range, stems shade each other and the stool suffers.
Safety
Heavier cuts mean heavier hazards
The longer the rotation, the larger and heavier the stems, and the more a fall or a spring-back can injure. Use the felling and cutting rules in Felling Technique, and never cut alone.
What’s Next
- Learn next: Coupe Layout & Mapping — laying out the sections
- Combine with: Yield Calculations per Acre — turning cycles into tonnes