Stand-Damage Variables

The model uses many variables. Each one is described below.
Page, Equation, Table, and Figure references are found in the DOS User's Guide (Ref:), the Model Description (Des:), and the Interface Guide (Int:).

  • Colbert, J. J.; Sheehan, Katharine A. 1995. Description of the Stand-Damage Model: part of the Gypsy Moth Life System Model. U.S. Forest Service. 111 p.
  • Racin, G.E. & Colbert, J.J.. 1995. Guide to the Stand-Damage Model Interface Management System. US Forest Service. 149 p.
  • Colbert, J.J. and Racin, G.E. 1995. User's guide to the Stand-Damage Model: a component of the Gypsy Moth Life System Model. US Forest Service. 38 p.
  • Disk File Name
     Enter a name up to 8 characters long.  All
     non-alphanumerics that are entered are removed
     from the name.  It will change the string " My File$"
     to "MyFile"; "MyFile.a" is changed to "MyFile"  The
     extension ".INP" is added when a file is saved,
     resulting in the name "MYFILE.INP"  The Arrow keys move
     the cursor between data fields. The active disk file is
     shown in the lower left corner of the screen.
    
           Page   Equation   Table   Figure
     Ref:   23
     Int:    4
    
    User Name
     Enter a character string of up to 20 characters.  This
     name will be part of the input data file when the file
     is saved to disk.  The Arrow keys move the cursor
     between data fields.
    
           Page   Equation   Table   Figure
     Ref:   23
     Int:   23                 2
    
    Job/Study Title
     Character string used to help organize your
     simulations.  A study name or other global identifier
     may be appropriate.  The Arrow keys are used to move
     between data fields.
    
           Page   Equation   Table   Figure
     Ref:   23
     Int:   23                 2
    
    Site/Stand Location Identification
     Character string to help organize input data for the
     simulation model.  Enter a plot number or other
     descriptive data to assist in associating data with
     the source stand.
    
           Page   Equation   Table   Figure
     Ref:   23
     Int:   23                 2
    
    Date
     Every file has a "creation" date, so you may want
     to provide a field collection date for the data.  (As
     with all the fields on this screen, you are free to
     use them to your best advantage.)  Note that the
     following field is a separate sub-screen so that
     exiting it is different.
    
           Page   Equation   Table   Figure
     Ref:   23                        17
     Int:   23                 2
    
    inventory_year
     The inventory year for simulation.  The variable
     ISYEAR is intialized at the start of the simulation
     to this value (inventory_year).  ISYEAR is increment-
     ed at the start of each simulated year to provide
     the calendar years simulated.  If you change this,
     check to ensure that scheduled defoliation or stand
     management is still within the simulation period.
     Note: In the manuals, this variable is referred to
     as the Start year (ISYEAR) and has values starting
     with the first year of simulation, i.e., the first
     growing year after inventory.
    
     DEFAULT: 1979
     UNITS: Calendar year
     RANGE: Any calendar year (>=0)
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:    5                         1
     Int:   23                 2
    
    NYEARS
     The number of years that you want the simulation to
     last. It is used to index the simulation by adding one
     less than the value provided to the start year to get
     the last year.  Use these as the first and last
     calendar years of the simulation.  If you change this,
     make sure to check to ensure that any scheduled
     defoliation or stand management is still within the
     simulation period.
    
     DEFAULT: 5
     UNITS: number of years
     RANGE: >0
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:    5                         1
     Int:   23                 2
    
    ISEED
     Random number seeds for the stand-damage model: random
     components of tree establishment and tree stress
     mortality that effect the model's trajectory.  By
     choosing a different seed for each of several distinct
     simulations while holding all other parameters
     constant, you can see the effect of the random number
     on the model's output.  ISEED[1] is used in
     recruitment and ISEED[3] is used in stress affects on
     tree mortality.  The function uses 5 and 8192 as the
     two relatively prime generators.  Setting ISEED[1] to
     zero yields constant maximum recruitment.  Setting
     ISEED[3] to zero keeps the stress mortality "on" all
     the time.
    
     DEFAULT: ISEED[1]= 2653; ISEED[3]= 3745
     UNITS: None
     RANGE: 0 < N < 8192
    
           Page   Equation   Table   Figure
     Ref:   24
     Des: 21,22   (19),(21)    6
     Int:   23                 2
    
    TFAC
     Scalar that will affect the total accumulated degree-
     days for each year as a multiplier: DEGDT =
     ANNDD(IY)*TFAC.  See equation (11).  Uniformly
     rescales the annual heat unit data (degree-days) or
     equivalently rescales all daily temperatures and the
     threshold temperature by the same factor. See equation
     (1) for daily temperatures and threshold use.
    
     DEFAULT: 1.0;
     UNITS: None
     RANGE: [0.0,10.0]
    
           Page   Equation   Table   Figure
     Ref:   24
     Des: 14,15     (11)               5
     Int:   23                 2
    
    Units of measure
     Units (METRIC or ENGLISH) used for model input and
     output.  Boolean FORTRAN variable name: METRIC.
    
     DEFAULT: English
     UNITS: None
     RANGE: metric [T], English [F]
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:   45ff
     Int:   24                 3
    
    pool_criteria
     The pooling criteria is the diameter measurement used
     for pooling tree cohorts.  If two diameter class
     cohorts are closer together in diameter than
     pool_criteria, then they are pooled into a single
     cohort.
    
     DEFAULT: 0.005;
     UNITS: meters
     RANGE: [0.0, 0.0508]
    
    out_criteria
     Width of stem diameter interval used to aggregate
     tree cohorts for their display in output tables.
    
     DEFAULT: 0.0508;
     UNITS: meters
     RANGE: [0.0254, 0.508]
    
    ISITE
     Soil moisture category:  1 = moist, 2 = intermediate,
     3 = dry. This is the relative index for the moisture
     regime of the stand.
    
     DEFAULT: 2
     UNITS: None
     RANGE: 1, 2, 3
    
           Page   Equation   Table   Figure
     Ref:   24
     Des: 20,54
    
    PLOTAR
     Total sample area: this area is used to convert tree
     counts (provided by the user) to trees per acre (or
     per hectare), by dividing tree counts by this value.
    
     DEFAULT: 1.0 ac. (0.40 ha)
     UNITS: acre or hectare
     RANGE: [0.01, 1000] ([0.40, 404.7])
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:   2,4                2
     Int:   24                 3
    
    STNDAR
     Stand area is used only in computing stand-level
     summary-output statistics.
    
     DEFAULT: 1.0 ac. (0.40 ha)
     UNITS: acre or hectare
     RANGE: [0.01, 1000] ([0.40, 404.7])
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:    2                 2
     Int:   24                 3
    
    IBOUND
     Overstory-understory canopy boundary indicator. See
     HOVER - Boundary Height or Boundary Diameter (in
     Stand Details) for the value used to designate the
     boundary.
    
     DEFAULT: Diameter
     UNITS: None
     RANGE: Height or Diameter
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:  11,53
     Int:   24                 3
    
    DLENBASE
     Diameter class width, used to calculate the diameter
     class centers and boundaries.  All diameter classes
     are of equal width, starting at 0.0; the first class
     is from 0.0 to DLENBASE and has midpoint DLENBASE/2.0
    
     DEFAULT: 2.0 in. (5.08 cm)
     UNITS: inches or centimeters
     RANGE: [2.0, 4.0] ([5.08, 10.16])
    
           Page   Equation   Table   Figure
     Ref:   24
     Des:    2
     Int:   25                 3
    
    HOVER
     Depending on the value of IBOUND:
     diameter of tree at overstory-understory boundary,
     OR
     height of tree at overstory-understory boundary
    
     DEFAULT: Diam. = 6.0 in. (15.24 cm)
              Ht. = 6.0 ft. (1.83 m)
     UNITS: diam.-in.; ht.-ft. (diam.-cm; ht-m)
     RANGE: diam. [1.0, 50.0] ([2.54, 127.0])
            ht. [1.0, 100.0] ([0.305, 30.48])
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des: 11,53
     Int:   24                 3
    
    TLIGHT
     Parameter for calculating available light in equation
     (10).  Botkin et al. (1972) suggest using latitude and
     aspect to adjust this parameter.
    
     DEFAULT: 1.0
     UNITS: None
     RANGE: [0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des: 12,24,55  (10)               3
     Int:   24                 3
    
    TKL
     Exponential decay parameter for calculating available
     light.  See equation (10) and Figure 3.
    
     DEFAULT: 0.0002
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des: 12,24,55  (10)               3
     Int:   24                 3
    
    SHX
     X value used in linear interpolation function to
     calculate shade index as a function of the available
     light on diameter growth.  See equation (10) and
     Figure 4.   Each of the six sets contains four (x,y)
     point pairs.
    
     DEFAULT: Species group dependent
     UNITS: Proportion (of available light), between 0.0
     and 1.0.
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  14,54    (10)       4       4
     Int:   24                 3
    
    SHY
     Y value used in linear interpolation function to
     calculate shade index as a function of the available
     light on diameter growth.  See equation (10) and
     Figure 4.   Each of the six sets contains four (x,y)
     point pairs.
    
     DEFAULT: Species group dependent
     UNITS: Shading index, between 0.0 and 1.0.
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  14,54    (10)       4       4
     Int:   24                 3
    
    PLOTSZ
     Area for calculating influence of surrounding trees on
     the shading of a given tree.  See equation (9).
    
     DEFAULT: 0.2 ac. (0.08 ha)
     UNITS: acre or hectare
     RANGE: [0.0001, 20.0] ([4.05E-5, 8.09])
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  12,54     (9)               3
     Int:   25                 3
    
    SHADMN, TEMPMN
     SHADMN: Minimum value for SHADE in equation (16) and
       Figure 4.
     TEMPMN: Minimum value for TEMP in equation (11b) and
       (16).  See Figure 5.
    
     DEFAULT: 0.05;
     UNITS: None
     RANGE: [0.0,1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des: 14,54   (16),(11b)         4,5
     Int:   25                 3
    
    CRWDMN
     Minimum value for CROWD in equation (12).
    
     DEFAULT: 0.75;
     UNITS: None
     RANGE: [0.0,1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  15,32,50 (12)               6
     Int:   25                 3
    
    DFOLDE
     Rate coefficient to decrease foliage production
     FOL(IH,IS) current year in the overstory (IS=1) and
     understory (IS=2) strata due to last year's
     defoliation.   Reset to 0.0 to eliminate the effect
     of prior defoliation on current foliage production.
    
     DEFAULT: 0.15;
     UNITS: None
     RANGE: [0.0,1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:    8
     Int:   25                 3
    
    DFLC(1,x)
     Linear effect curve, equation (13), for current
     defoliation on current diameter growth, DEFIND
     (equation (16)).   Light prior defoliation.
    
     Intercept: DFLC(1,1) - DEFAULT:  0.968895;
                            RANGE:    [0.8,1.0]
     Slope:     DFLC(1,2) - DEFAULT: -0.00405025;
                            RANGE:   [-0.008,0.0]
     UNITS: None
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  15,16 (13),(16)     7       7
     Int:   25                 3
    
    DFLC(2,x)
     1-over-linear effect curve, equation (14), for current
     defoliation on current diameter growth, DEFIND
     (equation (16)).  Heavy prior defoliation.
    
     Intercept: DFLC(2,1) - DEFAULT: 1.34177;
                            RANGE:  [1.0,5.0]
     Slope:     DFLC(2,2) - DEFAULT: 0.0053971;
                            RANGE:    [0.0,1.0]
     UNITS: None
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  15,16 (14),(16)     7       7
     Int:   25                 3
    
    STOCKS(x,1)
     Intercept term in quadratic equation for stocking
     class 'x'= ISTOCK(IH) to calculate relative stocking
     RSTOCK.  See S[s,1] in equation (8).
    
     UNITS: None
     RANGE:[-0.1,0.1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   10       (8)       4       2
     Int:   25                 3
    
    STOCKS(x,2)
     Linear term coefficient in quadratic equation for
     stocking class 'x'= ISTOCK(IH) to calculate relative
     stocking RSTOCK.  See S[s,2] in equation (8).
    
     UNITS: None
     RANGE:[-0.1,0.1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   10       (8)       4       2
     Int:   25                 3
    
    STOCKS(x,3)
     Quadratic term coefficient in quadratic equation for
     stocking class 'x'= ISTOCK(IH) to calculate relative
     stocking RSTOCK.  See S[s,3] in equation (8).
    
     UNITS: None
     RANGE:[-0.1,0.1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   10       (8)       4       2
     Int:   25                 3
    
    RSMULT
     Relative stocking multiplier used to account for the
     effect of relative stocking on tree growth.  See
     equation (12) and Figure 6.
    
     DEFAULT:0.0025
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   15      (12)               6
     Int:   25                 3
    
    STOKX
     X value used in linear interpolation function to
     calculate the relation between relative stocking and
     stem recruitment. Each of the five sets contains four
     (x,y) point pairs.  If greater than 100%, a stand is
     overstocked.
    
     UNITS: percentage
     RANGE:[0,120]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   22      (21)       4      10
     Int:   25                 3
    
    STOKY
     Y value used in linear interpolation function to
     calculate the relation between relative stocking and
     stem recruitment.  Each of the five sets contains four
     (x,y) point pairs.
    
     UNITS: Proportion (of possible maximum)
     RANGE: [0.0, 1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   22      (21)       4      10
     Int:   25                 3
    
    EPSIGR
     Determines whether small amounts of diameter growth
     should be calculated and carried.  Default of 0.0
     implies calculating and carrying all such amounts.
     As EPSIGR is increased, the diameter classes with
     associated stem counts, STEMS(IH,ID), below this value
     will not have associated diameter-growth calculations
     performed.
    
     DEFAULT: 0.0
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  18,72    (16)
     Int:   26                 3
    
    EPSITR
     Determines whether growth weighted by the stem count
     in a particular cell (host X diameter class) is
     sufficient to warrant moving some stems to the next
     larger diameter class.
    
     DEFAULT: 0.0
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  21,72    (20)
     Int:   26                 3
    
    EPSIMG[1]
     Determines whether there are sufficient stems in a
     cell to warrant their inclusion in the stem count for
     management, i.e., for removal.
    
     DEFAULT: 0.0
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  3,72                2
     Int:   26                 3
    
    EPSIMG[2]
     Determines if the total stem count within the
     user-selected diameter range is sufficient to warrant
     some removals.  Used only when a target residual
     stem count has been specified (MANAGE = 2).
    
     DEFAULT: 0.0
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  3,72                2
     Int:   26                 3
    
    EPSIMG[3]
     Determines if the number of stems designated to be cut
     is sufficient to warrant the removal.
    
     DEFAULT: 0.0
     UNITS: None, count
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  3,72                2
     Int:   26                 3
    
    PRTMIN
     Minimum stem count in a crown strata to warrant that
     it be included in the tabular output.  Default: 0.0
    
     DEFAULT:0
     UNITS: None
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:  23,74                      11
     Int:   26                 3
    
    SGMORT
     Exponential rate coefficient for effect of years of
     slow growth on tree mortality rate.  GDIE = 1.0 -
     exp[SGMORT * NSLOW(IH,ID)].
    
     DEFAULT: -0.084;
     UNITS: None
     RANGE: [-0.5,0.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   19      (18)               9
     Int:   25                3
    
    STRFAC[1]
     Proportion of trees that die when stress is not
     present, following heavy defoliation.  SDIE is set
     equal to this value when defoliation is heavy but no
     additional stress occurs.
    
     DEFAULT: 0.0
     UNITS: Proportion
     RANGE: [0.0, 1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   20      (19)
     Int:   25                 3
    
    STRFAC[2]
     Proportion of trees that die when stress is present,
     following heavy defoliation.  SDIE is set equal to
     this value when additional stress mortality is added
     to the defoliation mortality.
    
     DEFAULT: 0.15
     UNITS: Proportion
     RANGE: [0.0, 1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   20      (19)
     Int:   25                 3
    
    STRESS[]
     Probability that a stand with site index equal to the
     array index (1, 2, or 3) will be subject to additional
     unspecified stress.
    
     DEFAULT: STRESS[i] = 0.0, for i = 1,2,3
     UNITS: Number
     RANGE: [0.0, 1.0]
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   21      (19)
     Int:   25                 3
    
    ISOPT
     Tree stress option flag: 0 = no stress simulated; 1 =
     stress is simulated according to a uniform random
     probability function; 2 = stress in years that are
     specified by the user.  When ISOPT=2, an additional
     screen is presented for entering stress years.
    
     DEFAULT: 0
     UNITS: None
     RANGE: 0, 1, 2
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   21      (19)
     Int:   25                 3
    
     stress year: ISTR
     Year in which additional stress might affect tree
     mortality.  See stress mortality factors STRFAC(1)
     and STRFAC(2) for the effect.  The first of these will
     be in effect in stress years with none to light
     defoliation, the second will be in effect in years of
     heavy defoliation.  ISOPT  was previously set to 2 for
     this option to be in effect.
    
     DEFAULT: none
     UNITS: Calendar year
     RANGE: Any year within the simulation
    
           Page   Equation   Table   Figure
     Ref:   25                         8
     Des:   20      (19)
     Int:    7
    
    degree-days
     Total accumulated number of degree-days for the year.
     Calculated using a threshold value of 42 degrees F.
     (5.5 degrees C) to calculate the daily amount to
     accumulate.
    
     DEFAULT: 4570 deg.F.*day
     UNITS: (degrees above 42)*day.
     RANGE: [500, 20,000] ([277.8, 11,111])
    
           Page   Equation   Table   Figure
     Ref:   30                        10
     Des:   23       (1)       6       5
     Int:   28                 5
    
    IPYEAR
     Interval for producing stand output.  Enter "0" to
     schedule specific years for output (within a special
     window) rather than producing output at regular
     intervals.  Enter a positive value n to obtain
     output every n years.
    
     DEFAULT:1
     UNITS: number of years
     RANGE:>=0
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                 2      11
     Int:   23                 2
    
    Stand Summary Table
     Logical (Yes/No) variable used to designate
     whether the stand summary information table should
     be produced.  Use Output Interval to set production
     frequency.  Set Output Interval to 0 to choose
     specific production years.
    
     DEFAULT:Yes
     UNITS: None
     RANGE:Yes,No
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                 2      11
     Int:   23                 2
    
    IGYEAR
     Output interval for producing ASCII data files of stem
     counts, basal area, volume, and quadratic mean
     diameter.  Use these files in graphics or statistical
     analysis packages.  They contain no legends or labels.
     Use Tree Graphic Category to control portion of the
     stand that is summarized.  If length of simulation is
     decreased so that no output will be produced (i.e.,
     IGYEAR > NYEAR), then IGYEAR will be reset to NYEAR.
    
     DEFAULT:2
     UNITS: number of years
     RANGE:0 to simulation length
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                       12-15
     Int:   23                 2
    
    ICAT
     Tree statistics summary control: options are
     overstory only, understory only, and both understory
     and overstory.
    
     DEFAULT:Overstory
     UNITS: None
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                       12-15
     Int:   26                        3
    
    Stem Count Summary Data Table
     Logical variable: "Yes" if stem count summary data are
     to be produced.  After simulation, view these data via
     the View output menu option.  These data can also be
     saved to a permanent file.
    
     DEFAULT:No
     UNITS: None
     RANGE:Yes,No
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                        12
     Int:   23                 2
    
    Basal Area Summary Data
     Logical variable: "Yes" if basal area summary data are
     to be produced.  After simulation, view these data via
     the View output menu option or to see a plot of these
     data, select Graph from the Output pull-down.  These
     data can also be saved to a permanent file.
    
      DEFAULT:No
      UNITS: None
      RANGE:Yes,No
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                        13
     Int:   23                 2
    
    Tree Volume Summary Data
     Logical variable: "Yes" if tree volume summary data are
     to be produced.  After simulation, view these data via
     the View output menu option or to see a plot of these
     data, select Graph from the Output pull-down.  These
     data can also be saved to a permanent file.
    
     DEFAULT:No
     UNITS: None
     RANGE:Yes,No
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                        14
     Int:   23                 2
    
    Tree Diameter Summary Data
     Logical variable: "Yes" if tree diameter summary data
     are to be produced.  After simulation, view these data
     via the View output menu option or to see a plot of
     these data, select Graph from the Output pull-down.
     These data can also be saved to a permanent file.
    
     DEFAULT:No
     UNITS: None
     RANGE:Yes,No
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:   23                        15
     Int:   23                 2
    
    Stem Count
     Logical variable: "Yes" if stem counts are to be
     produced.  After simulation, view these data via
     the View output menu option or to see a plot of
     these data, select Graph from the Output pull-down.
     These data can also be saved to a permanent file.
    
     DEFAULT:No
     UNITS: None
     RANGE:Yes,No
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des:    4                 2      11
     Int:   23                 2
    
    IVIEW[]
     The years that the stand output summary table is to be
     produced.  You have selected to stipulate specific
     years in which to have the stand summary information
     placed in the output table.  This was done by setting
     the Output interval (parameter IPYEAR) equal to 0.
    
     UNITS: Calendar year
     RANGE:Between Starting Year and Ending Year
    
           Page   Equation   Table   Figure
     Ref:   30                         7
     Des: 39,41,43
     Int:   23                 2
    
    management year: MYEARS
     Select a year during the proposed simulation in which
     to have tree removal.  Select the method and diameter
     range of harvested trees to selectively and
     conditionally remove trees of each species.  To change
     the method for a year that already has been selected,
     first delete that year, then add it with the other
     method selected.
    
     UNITS: Calendar Year
     RANGE:Between starting year and ending year
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    management method: MANAGE
     Select the criteria used for tree removal: 1 = specify
     proportions of stems to be cut and diameter boundaries
     for cut of each species; 2 = specify target number of
     stems to remain following cut along with the diameter
     range for stem removal for each species.  The target
     number of stems will include all stems outside the
     specified diameter range. Only one method can be
     applied in any one year.
    
     UNITS: None
     RANGE:1,2
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    CUTMIN(h)
     Minimum diameter to be considered in the removal of
     this tree species. This number is compared to the
     class midpoint in deciding whether to include trees
     within this class.
    
     DEFAULT: 2.0 in. (5.08 cm)
     UNITS: inches or centimeters.
     RANGE: [0.0, 50.0] ([0.0, 127.0])
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    CUTMAX(h)
     Maximum diameter to be considered in the removal of
     this tree species. This number is compared to the
     class midpoint in deciding whether to include trees
     within this class.
    
     DEFAULT: 20.0 in. (50.8 cm)
     UNITS: inches or centimeters.
     RANGE: [0.0,100.0] ([0.0, 254.0])
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    TARGET/PROPORTION
     The target number of stems to remain following the cut
     if TARGET option was specified, or the proportion of
     stems to remove for the PROPORTION option.  This can
     vary between species.
    
     DEFAULT: 50.0 (123.55); none
     UNITS: Target: count/acre (count/ha); Prop.: none
     RANGE: [1.0, 1.0E+5] ([2.47, 2.47E+5]); [0.0, 1.0]
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    management year to delete
     Enter management year to delete.  Once deleted, data
     will be lost.  The data must then be reentered or
     retrieved from an existing disk file.
    
     UNITS: Calendar year.
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    management year: MYEARS
     Choose from a pick-list of current management years.
     Select specific years by "checking" them with the
     space bar.  Management data sets are provided for the
     selected years.
    
     UNITS: Calendar year.
    
           Page   Equation   Table   Figure
     Ref:   29                        12
     Des:    3                 2
     Int:   29                 7
    
    defoliation year: IDFOLY
     Enter a year in which defoliation will occur.  The
     year must be within the simulation period.  Once a
     valid year is entered, specify defoliation for that
     year by species and canopy strata (overstory and
     understory).
    
     UNITS: Calendar year.
    
           Page   Equation   Table   Figure
     Ref:   28                        11
     Des:   11   (13-14)(19)   7       7
     Int:   28                 6
    
    overstory defoliation per cent: DEFL(1,IH)
     Defoliation for the overstory canopy strata (large
     trees) for each species (IH) for the year chosen.
    
     UNITS: percent
     RANGE:[0.0, 100.0]
    
           Page   Equation   Table   Figure
     Ref:   28                        11
     Des:   11   (13-14)(19)   7       7
     Int:   28                 6
    
    understory defoliation per cent: DEFL(2,IH)
     Defoliation for the understory canopy strata (small
     trees) for each species (IH) for the year chosen.
    
     UNITS: percent
     RANGE: [0.0, 100.0]
    
           Page   Equation   Table   Figure
     Ref:   28                        11
     Des:   11   (13-14)(19)   7       7
     Int:   28                 6
    
    defoliation year to delete: IDFOLY
     Deletes defoliation year that has been stipulated
     previously.  Deletes year and associated data from
     the list of user-supplied defoliation data.
    
     UNITS: Calendar year.
    
           Page   Equation   Table   Figure
     Ref:   28                        11
     Des:   11   (13-14)(19)   7       7
     Int:   28                 6
    
    defoliation year to edit: IDFOLY
     Edit defoliation years by marking them with the space
     bar.  After selecting years, edit the defoliation data
     associated with each year.
    
     UNITS: Calendar year.
    
           Page   Equation   Table   Figure
     Ref:   28                        11
     Des:   11   (13-14)(19)   7       7
     Int:   28                 6
    
    tree names
     Edit parameters for host species by marking them with
     the space bar.  Edit initial stem counts in 20
     diameter classes, initial defoliation history, and all
     of the model's host species specific parameters.
    
     UNITS: Host species by common name
    
           Page   Equation   Table   Figure
     Ref:   27
     Des:    2                 1       1
     Int:   27                 4
    
    delete host species
     Verify removal of the selected species from the stand.
     Once a species has been deleted, you cannot retrieve
     its data.  Be certain you will not want these data
     before proceeding.  The "safety" response (currently
     set to "No") must to be changed before the species can
     be deleted.
    
     UNITS: Host species by common name
    
           Page   Equation   Table   Figure
     Ref:   27
     Des:    2                 1       1
    
    host species to delete
     Remove selected species from the stand.  You cannot
     remove all species because some trees must be present
     when the simulation is run.  To completely replace
     the existing stand, add one new species before
     deleting the last species in the current list.
    
     UNITS: Host species by common name
    
           Page   Equation   Table   Figure
     Ref:   27
     Des:    2                 1       1
     Int:   27                 4
    
    Scientific Name (latin binomial)
     Scientific name for species. With User-Defined
     species, enter the scientific name or other
     identifying text here.
    
    Feeding Preference
     Refers to the palatability of this species to gypsy
     moth.  The choices are Susceptible, Resistant,
     and Immune.  See Liebhold et al. 1995, Gen. Tech. Rpt.
     NE-211, Northeastern Forest Experiment Station, USDA-
     Forest Service, for tree species in North America.
    
     UNITS: None
     RANGE: 1, 2, 3
    
    STEMS
     The number of trees by species and diameter class.
     The class midpoint is used to index the current field.
     There are 20 classes for each tree species.  Before
     Stem counts are used in the model, they are converted
     to a per acre (or per hectare) basis by multiplying
     stem count by the reciprocal of Plot Area.
     The diameter class width can be edited in Stand data.
    
     DEFAULT: 0.0 (except smallest class where 1.0)
     UNITS: count/acre (or /ha)
     RANGE: [0.0, 1.0E+5] ([0.0, 2.47E+5])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:    2                 1       1
     Int:   27                 4
    
    IDHIST(h,i,j)
     Tree species (h) specific index of defoliation history
     for overstory trees (i = 1) or understory trees (i =
     2) during each of the past 2 years (j). Values of 0
     (none), 1 (light = 1-30%), 2 (moderate = 31-65%), or 3
     (heavy = >65%) are determined as shown in Table 7.
     This value is used as a key to one of the two
     regression equations (13) or (14) shown in Figure 7.
    
     UNITS: Category
     RANGE: 0, 1, 2, 3
    
           Page   Equation   Table   Figure
     Ref:   28                        11
     Des:   11   (13-14)(19)   7       7
     Int:   27                 4
    
    ISHADE(n,1) - recruitment
     There are five possible values, from most intolerant
     (1) to most tolerant (4); Red Maple (5) is described
     separately. The user can define a sixth class. See
     equation (21) for its use; Table 2 for its default
     values, and Figure 9 for graphs of the equation
     relating the class (curve no.) to the values used in
     the relationship.  In the definition above, "n" is
     the tree species currently being edited.
    
     UNITS: None, this is an index to one of five curves.
     RANGE:[1,6]
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   22      (21)              10
     Int:   27                 4
    
    ISHADE(n,2) - diameter growth
     There are six possible values, from most intolerant
     (1) to most tolerant (4); Red Maple (5) and Red Oak
     (6) are described separately.  See equation (16) for
     its use; Table 2 for its default values, and Figure 4
     for graphs of the equation relating the class (curve
     no.) to the values used in the relationship.  In the
     definition above, "n" is the tree species currently
     being edited.
    
     UNITS: None, this is an index to one of five curves.
     RANGE:[1,6]
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   22      (21)              10
     Int:   27                 4
    
    GROWR(h)
     Tree species specific relative growth rate parameter
     for currently selected host (h).  See equation (15)
     for use and Table 6 for values.
    
     UNITS: None
     RANGE: >0
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   17      (15)       6       8
     Int:   27                 4
    
    COLD(h)
     The coldest average annual degree-day accumulation
     marking the low temperature boundary for this species.
     See equation (11) for use, Figure 5 for effects, and
     Table 6 for values.  Equation (1) describes the method
     used to calculate degree-days. Accumulated differences
     between daily Max-Min/2.0 and 40.0 degrees Fahrenheit.
    
     DEFAULT: variable
     UNITS: degree-F.*day (degree-C.*day)
     RANGE: [500.0, 10,000.0] ([277.8, 5,555])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   14      (11b)      6       5
     Int:   27                 4
    
    HOT(h)
     The warmest average annual degree-day accumulation
     marking the high temperature boundary for this
     species.  See equation (11) for use, Figure 5 for
     affects and Table 6 for values.  Equation (1)
     describes the method used to calculate degree-days.
     Accumulated differences between daily Max-Min/2.0 and
     40.0 degrees Fahrenheit.
    
     DEFAULT: variable
     UNITS: degree-F.*day (degree-C.*day)
     RANGE: [3.0E+3, 2.0E+4] ([1.67E+3, 1.11E+4])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   14      (11b)      6       5
     Int:   27                 4
    
    AGEMAX(h)
     Maximum age for tree species.  This age is used to
     compute the annual mortality rate parameter BDIE in
     equation (17).
    
     UNITS: years.
     RANGE: >0
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   19      (17)       3
     Int:   27                 4
    
    SLOWD(h)
     Diameter growth threshold below which increased
     mortality is induced.
    
     DEFAULT: 0.01 in. (0.0254 cm)
     UNITS: inch or centimeter
     RANGE: [0.001, 1.0] ([2.54E-3, 2.54])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   19      (18)
     Int:   27                 4
    
    DMAX(h)
     Maximum diameter at breast height for tree species h.
     See equations (3) and (4) for use and Table 3 for
     values.  Used to calculate B1 and B2 parameters that
     are then used in equations (2) and (15).
    
     DEFAULT: variable
     UNITS: inches or centimeters
     RANGE: [2.0, 200.0] ([5.08, 508.0])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:    7      (3-4)      3
     Int:   27                 4
    
    HMAX(h)
     Maximum total height for tree species h.  See
     equations (3) and (4) for use and Table 3 for values.
     Used to calculate B1 and B2 parameters that are then
     used in equations (2) and (15).
    
     DEFAULT: variable
     UNITS: feet or meters
     RANGE: [10.0, 500.0] ([3.048, 152.4])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:    7      (3-4)      3
     Int:   27                 4
    
    SURFAR(h)
     Foliage biomass (dry weight) to foliage surface area
     conversion factor for tree species h.  See equation
     (10) for use and Table 6 for values.
    
     DEFAULT: variable
     UNITS: square inch per ounce
            square centimeter per gm
     RANGE: [100.0, 10,000.0] ([22.76, 2,276.])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   12      (10)       6
     Int:   27                 4
    
    ISTOKG(h)
     Relative stocking class for tree species h.  Values
     (1, 2, or 3) are found in Table 4 and used to
     stipulate the coefficients for one of the three
     equations shown in Figure 2.  They are used as
     subscript (s) for parameters S1, S2, and S3 in
     equation 8.
    
     UNITS: None
     RANGE: 1, 2, 3
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   10       (8)       4       2
     Int:   27                 4
    
    RECRUT(h)
     Maximum number of stems that can be recruited in one
     year to tree species h.
    
     DEFAULT: variable
     UNITS: stems/acre/year,
            stems/hectare/year.
     RANGE: [1.0, 1,000.0] ([2.47, 2,471])
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   22      (21)       6
     Int:   27                 4
    
    FDIE(h,m,n)
     Tree mortality rate for species (h), number of years
     of heavy defoliation (above 65%) (m), and site-
     moisture index (n).  DDIE = FDIE[h,m,n].
    
     UNITS: stems/year.
     RANGE:[0,1]
    
           Page   Equation   Table   Figure
     Ref:   27                         9
     Des:   20       19        8
     Int:   27                 4
    
    F1(h)
     Foliage biomass calculation parameter for species h.
     See equation (5) for use and Table 2 for values.
    
     UNITS: None
    
    F2(h)
     Foliage biomass calculation parameter for species h.
     See equation (5) for use and Table 2 for values.
    
     UNITS: None
    
    RESTIN(h,m)
     Number of resting sites per square meter of branch
     surface area on the current host (h), the understory
     and overstory crown (m=2) and boles of overstory trees
     (m=1).  See Table 2 for values and equation (7) for
     use of this parameter.
    
     UNITS: count/square cm.
    
    RESTIN(h,m)
     Number of resting sites per square meter of branch
     surface area on the current host (h), the understory
     and overstory crown (m=2) and boles of overstory trees
     (m=1).  See Table 2 for values and equation (7) for
     use of this parameter.
    
     UNITS: count/square cm.
    
    CR1(h)
     Tree species (h) specific parameter for predicting
     live crown ratio from stand basal area and tree
     diameter.  See equation (6) for use and Table 5 for
     values.
    
     UNITS: None
    
    CR2(h)
     Tree species (h) specific parameter for predicting
     live crown ratio from stand basal area and tree
     diameter.  See equation (6) for use and Table 5 for
     values.
    
     UNITS: None
    
    CR3(h)
     Tree species (h) specific parameter for predicting
     live crown ratio from stand basal area and tree
     diameter.  See equation (6) for use and Table 5 for
     values.
    
     UNITS: None
    
    CR4(h)
     Tree species (h) specific parameter for predicting
     live crown ratio from stand basal area and tree
     diameter.  See equation (6) for use and Table 5 for
     values.
    
     UNITS: None
    
    View output file
     Move the highlight bar to the desired output and press
     Enter.  Once an output is selected, the Arrow, Page-
     up, and the Page-down keys can be used to navigate
     through the table.
    
           Page   Equation   Table   Figure
     Ref:   31                         7
     Des:   23                       11-15
     Int:   16                        19
    
    Save output file
     Decide which temporary file(s) should be saved to
     disk. The temporary Model output files are deleted
     unless you indicate with a "Yes" that they be saved.
     Enter a unique name for each file when you exit this
     section.
    
           Page   Equation   Table   Figure
     Ref:   31                         7
     Des:   23                       11-15
     Int:   15                        20
    
    Name output file
     Give the temporary file a name (with extension) so that
     the file can be saved on disk (e.g., VOLUMES.DAT).  Be
     careful not to overwrite an existing file.
    
           Page   Equation   Table   Figure
     Ref:   31                         7
     Des:   23                       11-15
     Int:   15
    
    Summary table
     This is a temporary model output file.  Use the Arrow,
     Page, or Ctrl-Left/Ctrl-Right Arrow keys to move
     portions of this text file into view.  Save this file
     by: (1) Select "Save" from the Output pull-down menu;
     (2) Change the default "no" to "yes" using the space
     bar; (3) Press ESC key and enter a unique file-name in
     the space provided.  Only the first 32K of this file
     will be shown.
    
           Page   Equation   Table   Figure
     Ref: 31,34                        5
     Des: 23-25                       11
    
    Stand Table-Stem Counts (trees/ac or trees/ha)
     This is a temporary model output file.  Use the Page
     and Arrow keys to view portions of this text file.
     WARNING: This file is overwritten when the simulation
     is rerun without saving this file first.  Save this
     file by: (1) Select "Save" from the Output pull-down
     menu. (2) Upon exiting the "Save" screen, enter a
     unique file name in the space provided.
    
    Basal area file (sq-ft/ac  or sq-m/ha)
     This is a temporary model output file.  Use the Page
     and Arrow keys to view portions of this text file.
     WARNING: This file is overwritten when the simulation
     is rerun without saving this file first.  Save this
     file by: (1) Select "Save" from the Output pull-down
     menu. (2) Upon exiting the "Save" screen, enter a
     unique file name in the space provided.
     Units: calendar year, then up to 20 columns of basal
          area in square-feet/ac or square-m/ha.
     File Format: Column 1: year of output, e.g., 1995.
           Up to 20 hosts per record, depending on number
           of hosts being simulated:
           Column 2: basal area for first species,
           Column 3: basal area for second species,
           Column 4: basal area for third species,
           etc.
    
           Page   Equation   Table   Figure
     Ref:   35                        18
     Des:   23                        13
    
    Volume file (cubic-feet/ac or cubic-m/ha)
    
    Diameter file (in. or cm.)
    
    Stem Counts (trees/ac or trees/ha)
    
    Graph output file
     Displays graph of specified output.  Move the
     highlight bar to the desired output and press Enter.
    
           Page   Equation   Table   Figure
     Ref:  31,35                      14
     Des:   23                       12-15
     Int:   16                        21