Description Usage Format Details
A dataset used for the examples on how to use the roughness method in the forestgales package.
It contains data for the input variables of the fg_rou
function.
Variables with NAs default automatically to a species-specific value, or to a constant.
Some variables are Essential, others are Desirable, and quite a few are Advanced. See the Wrapper Functions
documentation for more information on inputs.
The variables are as follows:
1 |
A data frame with 7 rows and 32 variables
stand_id. We think it's useful to tag stands for batch simulations. Essential.
date We think it's useful to date stands for batch/repeat simulations. Optional but mind the variables order in the 'fg_rou' function call.
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.
mean_ht. Mean tree height (m). Tree height is the main driver of vulnerability. Essential unless top_ht
is provided.
mean_dbh. Mean Diameter at Breast Height (cm). Dbh is the second main driver of vulnerability. Essential.
spacing. Current average spacing (m) between trees. Essential.
weib_a. Scale parameter (A, m s-1) 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. Shape parameter (k, dimensionless) 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.
top_ht. Stand top height (m). If mean_ht
is not provided, it can be calculated from top_ht
. Desirable unless mean_ht
is not available.
mean_cr_width. Mean tree crown width (m). Calculated from species-specific parameters relative to species
if not provided. Desirable.
mean_cr_depth. Mean tree crown depth (m). Calculated from species-specific parameters relative to species
if not provided. Desirable.
soil_group. Follows the soil classification described in the Critical Moments
documentation. If not provided it defaults to Soil A - Freely draining mineral soils. Desirable.
rooting. Categorised as: 1 - Shallow (<80cm); 2 - Deep (>80cm); 3 - The average of the Shallow and Deep values. Defaults to the Average value. Desirable.
new_edge. Differentiate between an established - green - edge (new_edge
= 0) and a new - brown edge (new_edge
= 1). It defaults to 0 (i.e. green edge). Desirable.
gap_size. Size (m) of the upwind gap. Defaults to 0m (i.e. no gap), which effectively treats the edge as a green edge. Desirable.
moe. Modulus of Elasticity (Young's modulus, Pa) of green wood. Defaults to species-specific values unless provided. Advanced.
mor. Modulus of Rupture (Pa) of green wood. Defaults to species-specific values unless provided. Advanced.
fknot. Knot factor (dimensionless), scaled (0, 1]. It defaults to species-specific values unless provided. Advanced.
stem_vol. Volume (m3) of the stem. Calculated with species-specific formulas and parameters unless provided. Advanced.
crown_vol. Volume (m3) of the crown. Calculated with species-specific formulas and parameters unless provided. Advanced.
stem_density. Density (kg m-3) of the green wood of the stem. It defaults to species-specific values unless provided. Advanced.
crown_density. Density (kg m-3) of the crown. It defaults to species-specific values unless provided. Advanced.
c_reg. 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. The value (dimensionless) of the drag coefficient at rest. See the Streamlining
documentation. It defaults to species-specific values unless provided. Advanced.
n_drag. The 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. The experimental wind speed limit (m s-1) used to calculate c_drag
and n_drag
. It defaults to species-specific values unless provided. Advanced.
snow_depth. Depth (m) of snow layer on the canopy. It defaults to 0m (no snow). Advanced.
snow_density. Density (kg m-3) of snow. It defaults to 150 kg m-3. Advanced.
ro. Air density (kg m-3). It defaults to 1.2226. Advanced.
x, y, z. Placeholders for stand (centroid) coordinates. Advanced.
dams. Detailed Aspect Method of Scoring values for UK. Only used to calculate probabilities of damage, not the CWS. Advanced.
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