Table 1.
Land-use and restoration scenarios
| Scenario | 5000 BP–0 BP | 1951–1999 | 2000–2024 | 2025 – 2099 |
|---|---|---|---|---|
| S1. Pristine forest remaining forest; no land use or land cover change | V: forest; P: stochastic; W: 0.0 m; F: none | V: forest; P: CMs; W: 0.0 m; F: none | V: forest; P: CMs; W: 0.0 m; F: none | V: forest; P: CMs; W: 0.0 m; F: none |
| S2. Peatland degradation; forest cleared, burned, and abandoned, minimal draining not maintained, high probability of fire. | Same as above | Same as above | V: ramp to foresta; P: CMs; W: 0.3 m, decliningb; F: high-frequency stochastic | V: increase to foresta; P: CMs; W: 0.3 m, decliningb; F: high-frequency stochastic |
| S3. Forest conversion to oil palm; forest cleared, burned and drained. Four 25-year oil palm rotations with prescribed fires. | Same as above | Same as above | V: oil palm (1×); P: CMs; W: 0.6 m; F: OP rotationc | V: oil palm (3×); P: CMs; W: 0.6 m; F: OP rotationsc |
| S4. Forest conversion to oil palm; forest cleared, burned and drained. Four 25-year oil palm rotations with one initial prescribed fire. | Same as above | Same as above | Same as above | V: oil palm (3×); P: CMs; W: 0.6 m; F: none |
| S5. Forest conversion to oil palm; forest cleared, burned, drained. One 25-year oil palm rotation followed by “optimum” restoration: forest recovers, drainage blocked, and no fire. | Same as above | Same as above | Same as above | V: increase to foresta; P: CMs; W: 0.0 m; F: none |
| S6. Forest conversion to oil palm (as no. 4); followed by abandonment. Forest sub-optimal recovery, drainage not maintained, low probability of fire. | Same as above | Same as above | Same as above | V: increase to foresta; P: CMs; W: 0.6 m, decliningb; F: low-frequency stochastic |
Note that 0 BP = 1950 CE
V vegetation, P precipitation (climate models (CMs)), W water table depth offset (down from peat surface) relative to pristine forest monthly water table depth simulation and fire (F)
aVegetation litter input to peat ramps from zero to full forest input in 25 years; restarts at zero following fire
bDitch effectiveness at lowering water not maintained; effectiveness declines linearly with peat height lost (see text)
c Fire at onset of each 25-year oil palm rotation burns 20 cm of peat