Figure 1.
The influence of field soils that were invaded or uninvaded by Al. petiolata (± sterilized) on (A) mycorrhizal colonization ( Fsugar maple= 77.7, df = 3,39, p < 0.001; Fred maple = 60.5, df = 3,39, p < 0.001; and Fwhite ash = 116.6, df = 3,39, p < 0.001) and (B) biomass accumulation ( Fsugar maple = 57.8, df = 3,39, p < 0.001; Fred maple = 61.4, df = 3,39, p < 0.001; and Fwhite ash = 70.1, df = 3,39, p < 0.001) of native tree seedlings. Bars represent the mean and standard error.
Figure 2.
The effect of soils conditioned with garlic mustard Al. petiolata (gm), sugar maple (sm), red maple (rm), or white ash (wa) on (A) mycorrhizal colonization ( Fsugar maple = 31.2, df = 4,49, p < 0.001; Fred maple = 18.2, df = 4,49, p < 0.001; and Fwhite ash = 22.1, df = 4,49, p < 0.001) and (B) increase in biomass ( Fsugar maple = 15.1, df = 4,49, p < 0.001; Fred maple = 18.1, df = 4,49, p < 0.001; and Fwhite ash = 13.2, df = 4,49, p < 0.001) of native tree seedlings. Bars represent the mean and standard error.
Figure 3.
The effects of extract of garlic mustard (gm), sugar maple (sm), red maple (rm), white ash (wa), or a water control on (A) mycorrhizal colonization of native tree seedlings ( Fsugar maple = 20.3, df = 4,49, p < 0.001; Fred maple = 19.8, df = 4,49, p < 0.001; and Fwhite ash = 25.4, df = 4,49, p < 0.001 [Experiment 3]), (B) increase in biomass of native tree seedlings ( Fsugar maple = 11.7, df = 4,49, p < 0.001; Fred maple = 14.2, df = 4,49, p < 0.001; and Fwhite ash = 27.9, df = 4,49, p < 0.001 [Experiment 3]), and (C) percent germination of native AMF spores ( FGlomus = 17.3, df = 4,49, p < 0.001; and FAcaulospora = 21.8, df = 4,49, p < 0.001 [Experiment 4]). Bars represent the mean and standard error.
Figure 4.
(A) Effect of mycorrhizal dependency on Al. petiolata reduction of AMF colonization.
(B) Effect of mycorrhizal dependency on Al. petiolata reduction in plant growth. Mycorrhizal dependency was calculated separately as the difference between plant growth in the presence and absence of AMF. Different colors represent plants with different life-history strategies, as follows: yellow dot, herbaceous colonizers of disturbed edges and bare ground; reddish brown dot, herbaceous edge and gap species; blue dot, woody colonizers of forest edges and gaps; black dot, tree species of mature forest. Species are labeled as follows (with mean mycorrhizal colonization in soil not conditioned by garlic mustard ± standard error in parentheses): 1 = Ci. intybus (18.5 ± 4.1), 2 = Tr. repens (46.7 ± 6.3), 3 = Pl. major (28.2 ± 3.7), 4 = Ta. officinale (37.3 ± 2.5), 5 = S. canadensis (48.0 ± 6.2), 6 = C. leucanthemum (34.6 ± 3.1), 7 = D. carota (40.4 ± 6.2), 8 = As. syriaca (52.1 ± 5.8), 9 = J. virginiana (31.2 ± 4.4), 10 = Po. deltoids (63.9 ± 4.5), 11 = M. alba (38.6 ± 5.9), 12 = Pr. virginiana (28.4 ± 4.2), 13 = Fr. americana (65.9 ± 5.3), 14 = Ac. saccharum (46.3 ± 3.7), 15 = Ac. rubrum (59.5 ± 5.7), 16 = Pr. serotina (34.8 ± 5.5).