Figure 6: The same as in Figure 5 except that the measurements were made on 20 species in a heavily grazed pasture. Abbreviations of plant species are defined in Table 1, as well as: Astagr = Astragalus agrestis Douglas ex G. Don., Lacobl =Lactuca tatarica (L.) C.A. Mey. var. pulchella (Pursh) Breitung [Lactuca oblongifolia Nutt.], Ratcol=Ratibida columnifera (Nutt.) Woot. & Standl., and Vicame=Vicia americana Muhl. ex Willd. et al.