The Great Lakes create thermal gradients that impact temperature and precipitation, particularly snow, but these effects also determine the success of fruit trees, the distribution of ant species and the phenology of plants and insects. Moreover, what is most interesting, is that the gradients reverse with season, making the climate effects of the Great Lakes a fascinating ecological laboratory.
Warren II, R.J. and S. Vermette. 2022. Laurentian Great Lakes warming threatens northern fruit belt refugia. Int Journal of Biometeorology 66: 669-67.
Warren II, R.J., S. Bayba and K. Krupp. 2018. Interacting effects of urbanization and coastal gradients on ant thermal responses. JOURNAL OF URBAN ECOLOGY 4: 1.
Armstrong, J. and R.J. Warren II. In Progress. Pollination synchrony along a Great Lakes thermal gradient.
Kenline, M. and R.J. Warren II. In Progress. The effect of great lake thermal gradients on pollinating Diptera and Hymenoptera.
Plant seed dispersal by ants (myrmecochory) is a long known species interaction (~100 years); however, we recently discovered a parallel phenomenon whereby ants also disperse wasp-induced oak galls, with much the same patterning in propagule attractants and ant retrieval. This discovery opens up multiple avenues of research, including what is the evolutionary impetus for the interaction (e.g., parasite protection?), what environmental conditions mediate the interaction and what ant species are most likely to participate?
Warren II, R.J., A. Guiguet, C. Mokadam, J.F. Tooker and A. Deans. 2022. Oak galls exhibit ant dispersal convergent with myrmecochorous seeds. THE AMERICAN NATURALIST 200: doi.org/10.1086/720283
Myrica rubra (European fire ant) had invaded much of coastal Western New York, and its impacts include wiping out native ants and changing ecosystem energy flow. We have used the invasion to test niche and coexistence theories, and many questions remain, such as what are its impacts on native pollinators (particularly ground nesting species) as well as native birds.
Warren II, R.J. and C. Solomon†. 2022. Non-native stinging ant interactions with native anurans. ECOLOGICAL ENTOMOLOGY 47: 989-997.
Warren II, R.J., A. Mathew††, K. Reed††, S. Bayba††, K. Krupp†† and D.J. Spiering. 2019. Myrmica rubra microhabitat selection and putative ecological impact. Ecological Entomology 44: 239-248.
Goodman, M.† and R.J. Warren II. 2019. Non-native ant invader displaces native ants but facilitates non-predatory invertebrates. Biological Invasions 21: 2713-2722.
Warren II, R.J., K. Reed††, A. Mathew††, K. Krupp††, M. Goodman†, K. Archibald†† and D.J. Spiering. 2018. Release from intraspecific competition promotes dominance of a non-native invader. Biological Invasions 21: 895-909.
Invasive, non-native social insects appear to have inordinate impacts on native species of their own kind; the German yellowjacket (Vespula germanica) is no exception. Our research indicates that 70-96% of Western New York yellowjackets are V. germanica, with the lowest percentage in rural areas and the highest in suburbs and urban areas, where it prefers to nest in human structures rather than the ground.. The German yellowjacket is a voracious predator and current research is examining the impacts on non-yellojacket arthropods by this invasion.
Warren II, R.J. and J. Promowicz. In Review. Non-native Vespula germanica yellowjackets dominate urban-to-rural gradient
Promowicz, J. and R.J. Warren II. In Progress. Predatory impacts of German yellowjackets (Vespula germanica) on arthropod communities in Western New York
Plants poison each other (allelopathy), as well as themselves (autoxicity). We are interested how these inter- and intra-specific interactions contribute to the success (and possibly failure) of non-native invaders.
Warren II, R.J., A. Labatore and M. Candeias. 2017. Allelopathic invasive tree (Rhamnus cathartica) alters native plant communities.* PLANT ECOLOGY 218: 1233-1241
Pinzone, P., D. Potts, G. Pettibone, R.J. Warren II. Do novel weapons that degrade mycorrhizal mutualisms promote species invasion? Plant Ecology 219: 539-548.
Byrne, M. and R.J. Warren II. In Press. Intraspecific variation in Arabidopsis thaliana autotoxicity. Plant Ecology.
Byrne, M. and R.J. Warren II. 2025. Successful allelopathic competition is not limited to nonnative plants. International Journal of Plant Science
Native Americans shaped the landscape, sometimes by moving and propagating preferred plants. There is solid indication that the legacies of indigenous cultivation remains patterned into the landscape, and we seek to document those patterns.
Warren II, R.J. Ghosts of cultivation past - Native American dispersal legacy persists in tree distribution. PLoS ONE 11: e0150707.