Ecological Archives A025-123-A3
Ashley E. Larsen, Steven D. Gaines, and Olivier Deschênes. 2015. Spatiotemporal variation in the relationship between landscape simplification and insecticide use. Ecological Applications 25:1976–1983. http://dx.doi.org/10.1890/14-1283.1
Appendix C. Results excluding proportion of harvested cropland in large farms.
Table C1. Pooled model with fixed effects and year interactions, not including a covariate for large farms.
Notes: Proportion of harvested cropland in large farms was highly influential to the relationship between landscape simplification and insecticide use. Omitting this variable confounded the estimation of the relationship between landscape simplification and insecticide use resulting in generally different conclusions when this covariate was omitted. We used cluster robust standard errors, clustering at the agricultural statistics district. For all tables **,*, ~ indicates p < 0.01, p < 0.05, p < 0.1, respectively. For all tables, coefficients on landscape simplifications are shaded on a gradient to reflect their magnitude and sign. Green represents significant positive and red represents significant negative coefficients, and the intensity of the shading reflects the size of the coefficient. Coefficients <0.10 are light shading, coefficients 0.10< β < 0.20 are medium shading, coefficients 0.20< β <0.40 are dark and coefficients >0.40 are very dark.
Table C2. Region by year models not including proportion of harvested cropland in large farms.
Notes: Proportion of cropland harvested in large farms is highly influential to the regional relationship between landscape simplification and insecticide use. As with the pooled region model (Table A1), omitting this variable confounded the estimation of the relationship between landscape simplification and insecticide use resulting in generally different conclusions when this covariate was omitted. N = 17,305, R² = 0.64 and 0.67 for the pooled and region by year models respectively.