Statistical analyses
As a test of ELIA against biodiversity data components, we used the observed abundance (i.e. total number of butterfly observations) and species richness of butterflies and birds in the study transects. In order to disentangle the direct and indirect effects on biodiversity of energy storage and distribution, and of landscape composition and configuration, Structural Equation Models (SEM) were built for each of the studied biodiversity groups (butterflies, and breeding and wintering birds). Specific SEM were performed for species richness and abundance of all butterfly species clumped together and, in the case of birds, separately for nesting and wintering species. SEM considered the direct effects of the three ELIA components (E , I ,L ) and their indirect effects reflected in landscape composition (Cm) and configuration (Cn). In order to reduce the number and the redundancy of variables in the SEM, we performed a Principal Component Analysis (PCA) on Cm and Cn variables (Table 1 ). Analyses were performed using the SEM package in R (55 ).