Table 1. Parameters of best fitting linear regression models of changes in crop diversity and changes in area as a function of agricultural intensification (RI) based on wheat yield, or based on the area-weighted cereal (millet, sorghum, rice, wheat) yield and on area planted to the wheat or cereals.
The last column shows the parameters of the best a model of changes in diversity and the area planted to the wheat or cereals.
| RI Crop(s) | Variable | Response | ||
|---|---|---|---|---|
| Wheat | Δ Diversity | Δ Proportional Area | Δ Diversity | |
| Intercept | 3.0*** | 0.0 | 2.4*** | |
| Δ RI | -11.6*** | 0.6*** | - | |
| Area (t0) | -4.4*** | -0.5*** | -12.6*** | |
| Δ Area | - | - | -10.0*** | |
| Δ Area x Area (t0) | - | - | -13.3*** | |
| R2 | 0.41 | 0.34 | 0.53 | |
| Degrees of freedom | 177 | 177 | 261 | |
| Cereals | Δ Diversity | Δ Proportional Area | Δ Diversity | |
| Intercept | 0.7 | 0.0 | -1.1* | |
| Δ RI | -8.5*** | 0.5*** | - | |
| Area (t0) | 2.5*** | -0.4*** | 1.3* | |
| Δ Area | - | - | -6.0*** | |
| Δ Area x Area (t0) | - | - | - | |
| R2 | 0.28 | 0.22 | 0.39 | |
| Degrees of freedom | 262 | 262 | 262 | |
Statistical significance of explanatory variables is denoted using asterisks (***P < 0.001, **P < 0.01, *P < 0.05).