Forestry

In the forestry module of ALCES®, the intended harvest of hardwood and softwood volume is specified (m3/yr). A maximum non-declining annual allowable harvest volume is simulated in ALCES® using Monte Carlo simulations for both hardwood and softwood and these values are compared to stakeholder defined Annual Allowable Cut (AAC) values for the study area. The User must decide on whether a fire regime should, or should not, be deployed during the landscape simulation. The maximum non-declining annual allowable harvest will be significantly lower if the fire regime is activated since fire is an additive disturbance regime shaping forest age class structure.

Other harvest constraints include the eligibility of different forest types and age classes for harvest, and the minimum acceptable wood volume. Other deletions from the active forest land base include:  steep slopes, inaccessible stands, riparian buffers, old-growth reserves, in-block roads, landings, and stands unavailable due to green-up (adjacency) delay. Differences in the suitability of sites for tree production were modelled by identifying the proportion of each forest type with low, medium and high site index values. Growth and yield production curves are used to grow all stands initiated by logging, fire, or following reclamation of energy sector footprints. Harvest and regeneration treatments are specified for each forest type, along with the probability of stands regenerating to a different forest type following a specific harvest and regeneration treatment. Since fires, other natural disturbances, and energy sector footprints are permitted to disturb forest stands in the simulation, forest sector harvest levels incorporate the wood salvage volume available within each forest type.

The forest harvest engine can be parameterized to follow a modified oldest-first, highest wood-density first entry queue. To ensure that high grading of old high-volume stands is not excessive, the model must be customized to ensure that a minimum volume of the AAC is harvested annually from eligible but lower volume stands.

Output variables relating to the forestry sector are generated by ALCES® for each time step, for each forest trajectory type, for each seral stage, and for each of hardwood and softwood separately, include:

• standing wood volume (m3);
• merchantable wood volume (m3);
• operable wood volume (m3);
• annual harvest volume (m3), area (ha), and edge (km);
• annual water consumption (m3; gross and net);
• direct and indirect labour (#);
• wood stumpage and royalty values ($/yr); and
• inblock road construction, maintenance and reclamation (area, edge, $).

Information on historical logging activity in the land base can be incorporated into each simulation by specifying the proportion of each forest type logged prior to the simulation period.

Table inputs

1.  Which forest trajectories can be harvested?
Within the active forest landbase, one or more forest trajectories may be identified as non-merchantable and thus ineligible for logging.  Reasons for excluding forest trajectories from logging include poor wood growth, wood form, harvesting costs, or market demand.  In this table, enter a value of 0 (non-merchantable) or 1 (merchantable).

2.  Hardwood and softwood harvest volume modifier wrt GID
Enter a "1" for those forest seral stages that are eligible for hardwood harvest, and a "0" for those seral stages that are ineligible.

3.  Which seral stages to harvest for hardwood and softwood
Enter a "1" for those forest seral stages that are eligible for softwood harvest, and a "0" for those seral stages that are ineligible.

4.  Minimum harvest volume m3/ha
Identify the minimum eligible stand volume (m3\ha) that can be harvested for each of hardwood and softwood. Enter the relative weighting of total trajectory wood volume versus wood density to be used by ALCES in determining which forest trajectories to harvest hardwood and softwood. The minimum weighting value for either wood volume or density is 0.2 and the maximum value is 0.8. The combined weighting for wood volume and density must sum to 1.0.

5.  Regeneration delay rates for FLB
Enter the proportion of Seral Stage 1 (generally stands of age 0-20 years) that fails to meet regeneration standards. Regeneration failures may be due to competition from other vegetation types, because of seedling failure, or because of herbivory by hares or ungulates (range of 0 to 1; 1=100%). These stands are either caught in regeneration delay or are re-treated with silvicultural practices. Identify whether regeneration delay occurs on the active and/or the passive forest landbase.

6.  Percent of FLB in different growth index categories
Identify the proportion of each forest trajectory found within each of low, medium, and high growth and yield curves. Site index is a forest stand ranking that predicts relative fiber production (range of 0 to 1; values must sum to 1.00 for each forest trajectory)

7.  Incremental % growth for each site index category
Relative to the default growth and yield curves entered in Tables 1 and 2 of Panel 7, identify the relative change in wood volume growth. Generally the value for medium growth and yield curves is 1 (=100 of default curves). A value of 1.2 for high would indicate a growth and yield curve 20% higher than medium, and a value of 0.8 for low growth and yield curves would indicate a 20% reduction relative to the medium curves.

8.  Percent of green trees removed
Enter the percent green trees within a cutblock removed by logging (range of 0 to 1; 1=100%).

9.  Net-down deletions for calculating active landbase
Enter the proportion of each forest trajectory that is ineligible for harvest because of steep slopes, inaccessibility, green-up delay, and riparian buffers. These values can range from 0 to 1 (1=100%) and should not include double counting (for example, steep slopes found within riparian buffer strips).  The User can also enter a minimum percentage of each forest trajectory that is to be maintained in the "old-growth" category. If the amount of Old Growth fall beneath this target value, the User can instruct ALCES to cease logging in the entire trajectory or to cease logging in only old growth stands. Enter the value 1 in the "Prevent only OG logging 1 or all Seral Stages 2" if you wish to preclude logging in only old growth stands and 2 if logging is to cease in all seral stages.

10.  Treatment type, regeneration and curve hopping
This table allows the user to identify harvest and regeneration treatments (clearcut/leave for natural, clearcut/plant, partial harvest, and understory protection) to be used for each forest trajectory. For trajectories where specific treatments may cause successional "jumps" to occur, the probabilities of such jumping can be defined.

11.  Wood salvage from fire, insect and energy sector damage
Enter the proportion of merchantable wood volume killed by fire or insects that is to be salvaged for either hardwood or softwood volume (range of 0 to 1; 1=100%). Also enter the proportion of the original volume remaining after a fire event. For example, a value of 0.8 (=80%) would indicate that 20% of the above ground volume is no longer available for salvage because of combustion or charring.

12.  Post-harvest change in growth & yield curves
Enter the projected positive or negative change in growth and yield of hardwood and softwood volume in each forest trajectory following harvest. This change is relative to the pyrogenic growth and yield curves that represent the base trajectory. For example, a value of 0.03 represents a 3% increase in growth and yield values relative to pyrogenic stands that have not yet been logged. A value of -.08 indicates an 8% decrease in post-harvest productivity relative to default pyrogenic curves.

13.  Inblock road metrics
Enter the percent of each cutblock area considered to be lost to inblock features (inblock roads and landings). Also enter the average anticipated lifespan of inblock features.

14.  Initial cutblock data & forest landbase harvested historical
Enter the percent of each forest trajectory that has been historically logged. Also enter the area and length of cutblocks for each forest trajectory that exists at the onset of the simulation exercise.

15.  Cutblock size and lifespan metrics
Enter the proportional distribution of cutblocks in different size classes (1-20, 21-40, 41-80, 81-160) (range 0 to 1; 1=100%). These values are used to calculate the amount of edge created by cutblocks.

16.  Plantation metrics
- Enter the average mean annual increment (m3 / year) for hardwood and softwood plantations.
- Enter the average rotation length (years) of hardwood and softwood plantations.

17.  Which footprints can be salvaged for wood harvest
For each land use footprint type, enter '1' if wood cleared from the footprint is salvaged.

Graphic inputs

Hardwood harvest target
The hardwood harvest trajectory identifies the intended harvest of hardwood volume during the simulation period. The x axis is years from present, and the y axis is cubic meters of intended harvest.

Softwood harvest target
The softwood harvest trajectory identifies the intended harvest of softwood volume during the simulation period. The x axis is years from present, and the y axis is cubic meters of intended harvest.

Switches

Wood harvest smoothing function
Turn this switch on to activate the wood harvest smoothing function.