Web structure (bipartite graph) of the studied plant-bee system in 2004 (a) and 2005 (b). S = specialization (flower types: A = actinomorphic, Z = zygomorphic, AS= Asteroideae, CI = Cichorioideae; pollen collecting: P = polylectic, oligolectic in Asteraceae = AST, Boraginaceae = BOR, Fabaceae = FAB, Malvaceae = MAL, Salicaceae = SAL; C = cuckoo bees); Lm = plant linkage level; ln: relative plant linkage level; D = distribution; number of plots with occurrence; B = body size group (a = small [ < 10 mm], b = medium [ > 10–12 mm], c = large (> 12 mm)); Lm = bee linkage level; ln: relative bee linkage level lm. For abbreviations of plant and bee species, see Appendix.