Agroforestation of Grasslands in Southeast Asia: WaNuLCAS Model Scenarios for Shade-Based Imperata Control During Tree Establishment - Smallholder Tree Growing for Rural Development and Environmental Services - page 143

Fig. 6.6 Measure of relative light received by Imperata as a function of basal area of P. falcataria ,
A. mangium and H. brasiliensis

Table 6.3 Regression of simulation and measurement of relative light received by Imperata as a
function of basal area of four species at different tree spacing
Tree species Weeding Tree

spacing

Equation R 2

Acacia mangium Measurement - Narrow y = −0.22Ln(×) + 0.67 0.89

Simulation No weeding Narrow - -

Wide - -

Partial weeding Narrow a y = −0.12Ln(x) + 0.44 0.85

Wide b y = −0.13Ln(x) + 0.45 0.86

Paraserianthes
falcataria

Measurement - Narrow y = −0.23Ln(x) + 0.80 0.81

Simulation No weeding Narrow y = −0.21Ln(x) + 0.72 0.93

Wide y = −0.21Ln(x) + 0.64 0.88

Partial weeding Narrow y = −0.14Ln(x) + 0.50 0.84

Wide y = −0.20Ln(x) + 0.61 0.91

Hevea
brasiliensis

Measurement - Narrow y = −0.25Ln(x) + 0.69 0.83

Simulation No weeding Narrow - -

Wide - -

Partial weeding Narrow y = −0.19Ln(x) + 0.51 0.85

Wide y = −0.18Ln(x) + 0.46 0.80

Swietenia
macrophylla

Simulation No weeding Narrow - -

Wide - -

Partial weeding Narrow y = −0.18Ln(x) + 0.56 0.81

Wide y = −0.13Ln(x) + 0.56 0.68

a narrow (timber trees: 4 × 2, 3 × 3, 4 × 4 m; rubber: 6 × 3, 5 × 3, 4 × 4 m)
b wide spacing (timber trees: 8 × 4, 8 × 8 m; rubber: 6 × 6, 12 × 6 m)