grid_disturbances.csv

grid_disturbances.csv allows you to specify cell-specific disturbance regimes.

• These disturbance regimes will override the disturbance inputs from rgroup.in
• This file will only be read if the appropriate flag in grid_setup.in is set.
• This file must contain an entry for every cell. It may have more entries than cells, but never less.

There are 11 columns in the disturbance file:

cell	fecal_pat_use	ant_mound_use	animal_burrows_use	kill_yr	killfreq_startyr	Prescribed_killfreq	extirp	grazing_frq	grazingfrq_startyr	ignition

cell

The number of the cell. Remember that cells are numbered by row and 0-indexed. For example a 4 x 4 grid would be numbered

0	1	2	3
4	5	6	7
8	9	10	11
12	13	14	15

fecal_pat_use

Either 0 or 1.

• 0 turns off fecal pats in the cell.
• 1 turns on fecal pats in the cell.

ant_mound_use

Either 0 or 1.

• 0 turns off ant mounds in the cell.
• 1 turns on ant mounds in the cell.

animal_burrows_use

Either 0 or 1.

• 0 turns off animal burrows in the cell.
• 1 turns on animal burrows in the cell.

kill_yr

Causes a wildfire in the cell at the specified year. Input 0 to turn off kill year.

killfreq_startyr

The start year of a fire regime. This input only matters when coupled with either Prescribed_killfreq or ignition.

Prescribed_killfreq

Input for prescribed wildfire frequency.

• 0 turns off prescribed fire.
• A whole number > 0 specifies a periodic return interval.
• A decimal value < 1 and > 0 specifies stochastic prescribed fire where the value is the probability of fire for a given year.

extirp

A value between 0 and N where N is the number of years of the simulation. Extirpates all rgroups in this cell in the given year. Input 0 to turn off.

grazing_frq

The interval between grazing events.

• 0 turns off grazing.
• A whole number > 0 specifies a periodic return interval.
• A decimal values < 1 and > 0 specifies stochastic grazing where the value is the probability of grazing for a given year.

grazingfrq_startyr

The start year for grazing. To turn off grazing input 0.

ignition

The cheatgrass-wildfire ignition coefficient.

• Input 0 to turn off cheatgrass-driven wildfire.
• 12.05 is the recommended value, derived from Fig. 2 of Whisenant et al. 1990 Changing fire frequencies on Idaho's Snake River Plains: ecological and management implications.

Example

Here is an example table for a 3 x 3 grid.

cell	fecal_pat_use	ant_mound_use	animal_burrows_use	kill_yr	killfreq_startyr	Prescribed_killfreq	extirp	grazing_frq	grazingfrq_startyr	ignition
0	0	0	0	0	0	0	0	0	0	0
1	0	0	0	0	5	80	0	0	0	0
2	0	0	0	0	0	0	0	0	0	12.05
3	0	0	0	0	1	100	0	0	0	0
4	0	0	0	50	0	0	0	0	0	0
5	0	0	0	0	0	0	0	20	1	0
6	0	0	0	0	0	0	0	20	1	0
7	0	0	0	0	0	0	0	20	1	0
8	0	0	0	0	10	.05	0	0	0	0

• In cell 0 no disturbances are specified.
• In cell 1 prescribed fires begin in year 5 and occur every 80 years.
• In cell 2 cheatgrass-driven wildfire is turned on with a ignition coefficient of 12.05.
• In cell 3 prescribed fires begin in year 1 and occur every 100 years.
• In cell 4 a single fire will occur in year 50.
• In cells 5-7 grazing occurs every 20 years starting in year 1.
• In cell 8 prescribed fire begins in year 10 and occurs stochastically with a 5% chance of occurring any given year.