Species-specific growth adjustment - Light

We derive the proportion of light intercepted by each species out of the total light intercepted by dividing the sward into vertical height layers of constant width, by default $0.05m$:

$$\begin{array}{rl}LI{G}_{ts}& =\sum _{z=l}^{L}LI{G}_{t,l}\\ LI{G}_{ts,l}& =IN{T}_{t,l}\cdot \frac{LA{I}_{ts,l}}{LA{I}_{tot,t,l}}\cdot \frac{1}{1-\exp ({\gamma }_{RUE,k}\cdot LA{I}_{tot,t})}\\ IN{T}_{t,l}& =\exp ({\gamma }_{RUE,k}\cdot \sum _{z=l+1}^{L}LA{I}_{tot,t,z})\cdot (1-\exp ({\gamma }_{RUE,k}\cdot LA{I}_{tot,t,l}))\end{array}$$

• ${\beta }_{LIG,H}$ controls how strongly taller plants get more light for growth, only used in the first method without height layers [-]

• ${\gamma }_{RUE,k}$ light extinction coefficient, only used in the method with height layers [-]

Visualization

• Effect of plant height on light competition:

layer method: light extinction coefficient γ_RUE_k [-]
Leaf area index species 1
Leaf area index species 2
Height species 2

• Visualization of the light competition in the height layers

Leaf area index species 1 [-]
Leaf area index species 2 [-]
Height species 1 [m]
Height species 2 [m]
Light extinction coefficient γ_RUE_k [-]

API

GrasslandTraitSim.light_competition! Function

light_competition!(
;
    container,
    above_biomass,
    actual_height
)

Calculate the distribution of potential growth to each species based on share of the leaf area index and the height of each species.

source

GrasslandTraitSim.light_competition_height_layer! Function

light_competition_height_layer!(; container, actual_height)

Divide the grassland into vertical layers and calculate the light competition for each layer.

source