Plant resource richness and diversity
Plant richness did not differ among periods but differed significantly among sites at the family level, but not at the species or morphotype level (Table 4; Appendix Fig S2). There were more plant families at site one (mean ± se) (4.4 ± 0.93) than site two (2.6 ± 0.4) (df = 5; t = 3.34; P = 0.021), while site three (3.0 ± 0.45) did not differ from either site one or two (P > 0.05). Moreover, plant diversity did not vary among sites or periods at any of the three classification levels (Table 4).