Myrmecochory, or seed dispersal by ants, is an important ecosystem service. North American deciduous forests are a hotspot of myrmecochory, with 30-40% of woodland forbs being dispersed by ants, including many well-known plants such as violets, trilliums, bloodroot, and wild ginger. Aphaenogaster rudis is a keystone seed-disperser responsible for ~74 % of seed dispersal events in these ecosystems. Myrmica rubra is an introduced seed-disperser from Europe that, like many other introduced ants, form large, expansive colonies in its introduced range. This project investigates the ecological impacts of M. rubra on native ants, such as A. rudis, and subsequently on communities of woodland forbs. Further, many myrmecochorous plants that are dispersed by M. rubra in their native range have also been introduced, such as Chelidonium majus. We will investigate if interactions between invasive ants and plants facilitate their success and in turn how this will affect native plant communities.
Additional Scientific Information
Myrmica rubra is an introduced seed-dispersing ant. This project investigates the effects of M. rubra on a native “keystone disperser”, Aphaenogaster rudis, and on native plant communities. We are also investigating the potential for interactions between co-introduced species to influence invasion success (” invasional meltdown”). We will use a variety of methods to accomplish these goals. 1) Bait traps will be set out at KSR and surrounding sites to survey ant communities. 2) Seeds of native and introduced myrmecochorous plants will be offered to A. rudis and M. rubra colonies in lab and field trials to assess dispersal rates and preferences for native and invasive plant species. 3) A mesocosm experiment was implemented in 2012, in which 42 mesocosms (1 m diameter) were deployed in a red pine plantation at KSR. Colonies of A. rudis and M. rubra were added to these mesocosms along with four species of myrmecochorous plants: Anenome acutiloba, Asarum canadense, Sanguinaria canadensis (all native species), Chelidonium majus (invasive species). Seed dispersal of all species and emergence of C. majus was assessed in 2012. In 2013, we will measure the emergence and performance (e.g., biomass, seed set) of all four species.
Principal Investigator: Megan Frederickson
Researcher(s): Kirsten Prior