Figure 1.
Distribution of the 24 sites along the urbanization gradient around Lyon, France.
Base map colors represent: impervious surface (grey), agricultural landscape (yellow), semi-natural habitat (green) or water (blue).
Figure 2.
Mean species accumulation curve for pooled data from 2011 and 2012 (1000 randomizations).
Table 1.
Observed and estimated species richness.
Figure 3.
Effect of impervious surface percentage within 500 m on the abundance and species richness of bees.
A. Abundance of bees (filled circles = 2011, open circles = 2012); B. Species richness of bees (filled circles and full line = 2011, open circles and dashed line = 2012). Model for species richness = Impervious surface (Year) + Impervious surface2 (Year).
Table 2.
Generalized linear models for bee abundance and species richness depending on landscape variables.
Figure 4.
Effect of the proportion of impervious surface within 500 m on species occurrence based upon functional traits.
A. Nesting behavior (filled circles and full line = cavity-nesting species, open circles and dashed line = soil-nesting species); B. Parasitic or host behavior (filled circles and full line = parasitic species, open circles and dashed line = host species) species; C. Tongue length (filled circles and full line = short-tongued species, open circles and dashed line = long-tongued species).
Table 3.
Generalized linear models for the occurrence frequency of bee species depending on functional traits and landscape variables within 500 m.