Description Usage Format Details
A dataset used for the examples on how to use the TMC method in the forestgales package.
It contains data for only the Essential input variables of the fg_tmc
function (see the Wrapper Functions
documentation).
Non-essential (i.e. Desirable, or Advanced) variables are populated with NAs as they will default automatically to a species-specific value, or to a constant.
The variables are as follows:
1 |
A data frame with 8 rows and 42 variables
stand_id. We think it's useful to tag stands for batch simulations. Essential.
tree_id. We think it's useful to tag trees for batch simulations. Essential.
species. Vulnerability is to a large extent species-specific. Note that the species acronyms need to be wrapped in inverted commas (e.g. "SP" for Scots pine). Essential.
tree_ht. Tree height is the main driver of vulnerability (m). Essential.
dbh. Diameter at Breast Height (cm). Dbh is the second main driver of vulnerability. Essential.
spacing_current. Current average spacing of trees (m). When modelling thinnings, this is the spacing after thinning. Essential.
stand_mean_ht. The mean tree height of the trees in the stand (m). Used to calculate the effect of edge and gap, and indirectly to elevate the critical wind speeds (CWS) to match anemometer data. Essential.
stand_mean_dbh. The mean dbh of the trees in the stand (cm). Used indirectly to elevate the critical wind speeds to match anemometer data. Essential.
predominant_species. Required to calculate stand_top_ht
and/or stand_mean_ht
. Note that the species acronyms need to be wrapped in inverted commas (e.g. "SP" for Scots pine). Essential.
weib_a. Populated with NAs. Scale parameter (A) of the Weibull distribution of mean hourly wind speeds. This parameter is proportional to the mean wind speed. Only used to calculate probabilities of damage, not the CWS. In the UK, if weib_a
is not available it can be calculated from DAMS scores (see the Wrapper Functions
documentation).
weib_k. Populated with NAs. Shape parameter (k) of the Weibull distribution of mean hourly wind speeds. This parameter (typically ranging between 1 and 3) is indicative of the variability of the mean wind speeds (small values indicating larger variability). Only used to calculate probabilities of damage, not the CWS. Defaults to 1.85.
cr_width. Populated with NAs. Individual tree crown width (m). Calculated from species-specific parameters if not provided. Desirable.
cr_depth. Populated with NAs. Individual tree crown depth (m). Calculated from species-specific parameters if not provided. Desirable.
stand_cr_width. Populated with NAs. Mean tree crown width (m). Calculated from species-specific parameters relative to predominant_species
if not provided. Used to elevate the critical wind speeds to match anemometer data. Desirable.
stand_cr_depth. Populated with NAs. Mean tree crown depth (m). Calculated from species-specific parameters relative to predominant_species
if not provided. Used to elevate the critical wind speeds to match anemometer data. Desirable.
soil_group. Populated with NAs. Follows the soil classification described in the Critical Moments
documentation. If not provided it defaults to Soil A - Freely draining mineral soils. Desirable.
rooting. Populated with NAs. Categorised as: 1 - Shallow (<80cm); 2 - Deep (>80cm); 3 - The average of the Shallow and Deep values. Defaults to the Average value. Desirable.
dist_edge. Populated with NAs. Distance of an individual tree from the upwind stand edge (m). It defaults to 9 times stand_mean_ht
. Desirable.
gap_size. Populated with NAs. Size of the upwind gap (m). Defaults to 0m (i.e. no gap), which effectively treats all trees as "middle of the stand" trees. Desirable.
spacing_before. Populated with NAs. Average spacing of trees before a thinning (m). It defaults to spacing_current
. Desirable.
years_since_thin. Populated with NAs. Years since the last thinning. It defaults to 5 years (e.g. assumes full acclimation to new wind climate). Desirable.
moe. Populated with NAs. Modulus of Elasticity (Young's modulus) of green wood (MPa). Defaults to species-specific values unless provided. Advanced.
mor. Populated with NAs. Modulus of Rupture of green wood (MPa). Defaults to species-specific values unless provided. Advanced.
fknot. Populated with NAs. Knot factor, scaled (0, 1] (dimensionless). It defaults to species-specific values unless provided. Advanced.
stem_vol. Populated with NAs. Volume of the stem (m3). Calculated with species-specific formulas and parameters unless provided. Advanced.
crown_vol. Populated with NAs. Volume of the crown (m3). Calculated with species-specific formulas and parameters unless provided. Advanced.
stem_density. Populated with NAs. Density of the green wood of the stem (kg m-3). It defaults to species-specific values unless provided. Advanced.
crown_density. Populated with NAs. Density of the crown (kg m-3). It defaults to species-specific values unless provided. Advanced.
c_reg. Populated with NAs. Regression coefficient of the critical overturning moment vs stem weight. It defaults to species-specific values for the chosen soil_group
x rooting
depth combination unless provided. Advanced.
c_drag. Populated with NAs. Vvalue of the drag coefficient at rest. See the Streamlining
documentation. It defaults to species-specific values unless provided. Advanced.
n_drag. Populated with NAs. Exponent of the power fit of drag to wind tunnel data. See the Streamlining
documentation. It defaults to species-specific values unless provided. Advanced.
drag_upper_limit. Populated with NAs. Maximum wind speed used during the experiments from which n_drag
and c_drag
were derived (m*s-1). It defaults to species-specific values unless provided. Advanced.
snow_depth. Populated with NAs. Depth of snow layer on the canopy (m3). It defaults to 0m (no snow). Advanced.
snow_density. Populated with NAs. Density of snow (kg m-3). It defaults to 150 kg m-3. Advanced.
ci. Populated with NAs. Competition Index. Three options available: "None", "Bal", "Heg" (see Turning coefficients functions
documentation). It defaults to "None". Advanced.
ci_value. Populated with NAs. Value of the Competition Index. It defaults to 0. Advanced.
ro. Populated with NAs. Air density (kg m-3). It defaults to 1.2226. Advanced.
x, y, z. Populated with NAs. Placeholders for tree coordinates. Advanced.
dams. Populated with NAs. DAMS (Detailed Aspect Method of Scoring) value to describe the local wind climate (for UK conditions only). Only used to calculate probabilities of damage, not the CWS. Advanced.
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