We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Do novel weapons that degrade mycorrhizal mutualisms promote species invasion?
- Authors
Pinzone, Philip; Potts, Daniel; Pettibone, Gary; Warren, Robert
- Abstract
Non-native plants often dominate novel habitats where they did not co-evolve with the local species. The <italic>novel weapons hypothesis</italic> suggests that non-native plants bring competitive traits against which native species have not adapted defenses. Novel weapons may directly affect plant competitors by inhibiting germination or growth, or indirectly by attacking competitor plant mutualists (<italic>degraded mutualisms hypothesis</italic>). Japanese knotweed (<italic>Fallopia japonica</italic>) and European buckthorn (<italic>Rhamnus cathartica</italic>) are widespread plant invaders that produce potent secondary compounds that negatively impact plant competitors. We tested whether their impacts were consistent with a direct effect on the tree seedlings (<italic>novel weapons</italic>) or an indirect attack via degradation of seedling mutualists (<italic>degraded mutualism</italic>). We compared recruitment and performance using three <italic>Ulmus</italic> congeners and three <italic>Betula</italic> congeners treated with allelopathic root macerations from allopatric and sympatric ranges. Moreover, given that the allelopathic species would be less likely to degrade their own fungal symbiont types, we used arbuscular mycorrhizal (AMF) and ectomycorrhizal (ECM) tree species to investigate the effects of <italic>F. japonica</italic> (no mycorrhizal association) and <italic>Rhamnus cathartica</italic> (ECM association) on the different fungal types. We also investigated the effects of <italic>F. japonica</italic> and <italic>R. cathartica</italic> exudates on AMF root colonization. Our results suggest that the allelopathic plant exudates impact seedlings directly by inhibiting germination and indirectly by degrading fungal mutualists. Novel weapons inhibited allopatric seedling germination but sympatric species were unaffected. However, seedling survivorship and growth appeared more dependent on mycorrhizal fungi, and mycorrhizal fungi were inhibited by allopatric species. These results suggest that novel weapons promote plant invasion by directly inhibiting allopatric competitor germination and indirectly by inhibiting mutualist fungi necessary for growth and survival.
- Subjects
INTRODUCED species; INTRODUCED plants; PLANT species; PLANT classification; PLANT ecology
- Publication
Plant Ecology, 2018, Vol 219, Issue 5, p539
- ISSN
1385-0237
- Publication type
Article
- DOI
10.1007/s11258-018-0816-4