VegCA: Simulate plant competition with cellular automaton model for grass, shrubs, and trees#

class VegCA(*args, **kwds)[source]#

Bases: Component

Landlab component that simulates inter-species plant competition using a 2D cellular automata model.

This code is based on Cellular Automata Tree Grass Shrub Simulator (CATGraSS). It simulates spatial competition of multiple plant functional types through establishment and mortality. In the current code, tree, grass and shrubs are used.

Ref: Zhou, X., Istanbulluoglu, E., & Vivoni, E. R. (2013). Modeling the ecohydrological role of aspect controlled radiation on tree grass shrub coexistence in a semiarid climate. Water Resources Research, 49(5), 2872-2895.

Code author: Sai Nudurupati and Erkan Istanbulluoglu

Examples

>>> from landlab import RasterModelGrid
>>> from landlab.components import VegCA
>>> grid = RasterModelGrid((5, 4), xy_spacing=(0.2, 0.2))
>>> VegCA.name
'Cellular Automata Plant Competition'
>>> sorted(VegCA.output_var_names)
['plant__age', 'plant__live_index']
>>> sorted(VegCA.units) 
[('plant__age', 'Years'),
 ('plant__live_index', 'None'),
 ('vegetation__cumulative_water_stress', 'None'),
 ('vegetation__plant_functional_type', 'None')]
>>> grid['cell']['vegetation__plant_functional_type']= np.arange(
...        0, grid.number_of_cells, dtype=int)
>>> grid['cell']['vegetation__cumulative_water_stress'] = np.ones(
...        grid.number_of_cells)
>>> ca_veg = VegCA(grid)
>>> ca_veg.grid.number_of_cell_rows
3
>>> ca_veg.grid.number_of_cell_columns
2
>>> ca_veg.grid is grid
True
>>> import numpy as np
>>> A = np.copy(grid['cell']['plant__age'])
>>> ca_veg.update()
>>> np.alltrue(grid['cell']['plant__age'] == A)
False

References

Required Software Citation(s) Specific to this Component

None Listed

Additional References

Zhou, X., Istanbulluoglu, E., and Vivoni, E. R.: Modeling the ecohydrological role of aspect-controlled radiation on tree-grass-shrub coexistence in a semiarid climate, Water Resour. Res., 49, 2872– 2895, doi:10.1002/wrcr.20259, 2013.

Parameters
  • grid (RasterModelGrid) – A grid.

  • Pemaxg (float, optional) – Maximal establishment probability of grass.

  • ING (float, optional) – Parameter to define allelopathic effect of creosote on grass.

  • ThetaGrass (float, optional) – Drought resistance threshold of grass.

  • PmbGrass (float, optional) – Background mortality probability of grass.

  • Pemaxsh (float, optional) – Maximal establishment probability of shrub.

  • ThetaShrub (float, optional) – Drought resistance threshold of shrub.

  • PmbShrub (float, optional) – Background mortality probability of shrub.

  • tpmaxShrub (float, optional) – Maximum age of shrub (years).

  • Pemaxtr (float, optional) – Maximal establishment probability of tree.

  • Thetatree (float, optional) – Drought resistance threshold of tree.

  • PmbTree (float, optional) – Background mortality probability of tree.

  • tpmaxTree (float, optional) – Maximum age of tree (years).

  • ThetaShrubSeedling (float, optional) – Drought resistance threshold of shrub seedling.

  • PmbShrubSeedling (float, optional) – Background mortality probability of shrub seedling.

  • tpmaxShrubSeedling (float, optional) – Maximum age of shrub seedling (years).

  • ThetaTreeSeedling (float, optional) – Drought resistance threshold of tree seedling.

  • PmbTreeSeedling (float, optional) – Background mortality probability of tree seedling.

  • tpmaxTreeSeedling (float, optional) – Maximum age of tree seedling (years).

  • method (str, optional) – Method used.

  • Edit_VegCov (bool, optional) – If Edit_VegCov=True, an optional field ‘vegetation__boolean_vegetated’ will be output, (i.e.) if a cell is vegetated the corresponding cell of the field will be 1, otherwise it will be 0.

property Edit_VegCov#

Flag to indicate whether an optional field is created.

If Edit_VegCov=True, an optional field ‘vegetation__boolean_vegetated’ will be output, (i.e.) if a cell is vegetated the corresponding cell of the field will be 1, otherwise it will be 0.

__init__(grid, Pemaxg=0.35, ING=2.0, ThetaGrass=0.62, PmbGrass=0.05, Pemaxsh=0.2, ThetaShrub=0.8, PmbShrub=0.01, tpmaxShrub=600, Pemaxtr=0.25, ThetaTree=0.72, PmbTree=0.01, tpmaxTree=350, ThetaShrubSeedling=0.64, PmbShrubSeedling=0.03, tpmaxShrubSeedling=18, ThetaTreeSeedling=0.64, PmbTreeSeedling=0.03, tpmaxTreeSeedling=18, method='Grid', Edit_VegCov=True)[source]#
Parameters
  • grid (RasterModelGrid) – A grid.

  • Pemaxg (float, optional) – Maximal establishment probability of grass.

  • ING (float, optional) – Parameter to define allelopathic effect of creosote on grass.

  • ThetaGrass (float, optional) – Drought resistance threshold of grass.

  • PmbGrass (float, optional) – Background mortality probability of grass.

  • Pemaxsh (float, optional) – Maximal establishment probability of shrub.

  • ThetaShrub (float, optional) – Drought resistance threshold of shrub.

  • PmbShrub (float, optional) – Background mortality probability of shrub.

  • tpmaxShrub (float, optional) – Maximum age of shrub (years).

  • Pemaxtr (float, optional) – Maximal establishment probability of tree.

  • Thetatree (float, optional) – Drought resistance threshold of tree.

  • PmbTree (float, optional) – Background mortality probability of tree.

  • tpmaxTree (float, optional) – Maximum age of tree (years).

  • ThetaShrubSeedling (float, optional) – Drought resistance threshold of shrub seedling.

  • PmbShrubSeedling (float, optional) – Background mortality probability of shrub seedling.

  • tpmaxShrubSeedling (float, optional) – Maximum age of shrub seedling (years).

  • ThetaTreeSeedling (float, optional) – Drought resistance threshold of tree seedling.

  • PmbTreeSeedling (float, optional) – Background mortality probability of tree seedling.

  • tpmaxTreeSeedling (float, optional) – Maximum age of tree seedling (years).

  • method (str, optional) – Method used.

  • Edit_VegCov (bool, optional) – If Edit_VegCov=True, an optional field ‘vegetation__boolean_vegetated’ will be output, (i.e.) if a cell is vegetated the corresponding cell of the field will be 1, otherwise it will be 0.

update(dt=1)[source]#

Update fields with current loading conditions.

Parameters

dt (int, optional) – Time elapsed - time step (years).

WS_PFT(VegType, PlantType, WS)[source]#
assert_method_is_valid(method)[source]#
count(Arr, value)[source]#