Robert J. Warren II, Assistant Professor

« Please Note: Robert J. Warren II is no longer active on the CWT-LTER Project so contact information may not be accurate (see the CWT Personnel page for an up-to-date list of participants) »

Robert J. Warren II

Research Emphasis:

My research program focuses on how species interactions, including those involving exotic invaders, shift with environmental conditions and in the context of a changing global climate. Some big questions are: (1) How do positive and negative multi-trophic interactions shape niche requirements along environmental gradients? (2) How might co-evolved interactions, such as those between seed-dispersing ants and herbaceous plants, shift with climate change? (3) How often does the correspondence between a species' niche and its realized distribution become a mismatch?

Contact Information:

Primary Organization:  SUNY Buffalo State

Mailing Address:

Dr. Robert J. Warren II
123 Science and Mathematics Complex
1300 Elmwood Avenue
Buffalo, NY 14222


Web Page:

CWT Data Sets:

1209 (Nest-mediated seed dispersal study from mixed habitats in North Georgia and Western North Carolina)

1205 (Gleditsia triacanthos (honey locust) field experiments in Southern Appalachian Mountains region)

1206 (Gleditsia triacanthos (honey locust) greenhouse experiment)

1204 (Gleditsia triacanthos (honey locust) survey in Southern Appalachian Mountains region)

1203 (Tipularia discolor plant demography 1999-2004)

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CWT Publications and Presentations: (custom bibliography)

Journal Articles

Warren, R. J., Elliott, K. J., Giladi, I. , King, J. R. and Bradford, M. A. (2018), Field experiments show contradictory short- and long-term myrmecochorous plant impacts on seed-dispersing ants. Ecol Entomol. . doi:10.1111/een.12666

Warren, R.J., Love, J.P. & Bradford, M.A. (2017), Nest-mediated seed dispersal, Plant Ecol 218: 1213.

Warren RJ, II (2016) Ghosts of Cultivation Past - Native American Dispersal Legacy Persists in Tree Distribution. PLoS ONE 11(3): e0150707. doi:10.1371/journal.pone.0150707.

Warren, R. J., II, S. M. Pearson, S. Henry, K. Rossouw, J. P. Love, M. J. Olejniczak, K. J. Elliott, and M. A. Bradford. 2015. Cryptic indirect effects of exurban edges on a woodland community. Ecosphere 6(11):218.

Bradford, Mark A., Robert J.Warren II, Petr Baldrian, Thomas W. Crowther, Daniel S. Maynard, Emily E. Oldfield,William R.Wieder, Stephen A.Wood and Joshua R. King, 2014. Climate Fails to Predict Wood Decomposition at Regional Scales. In Nature Climate Change, Letters, advanced online publication at

Diez, Jeffrey M., Itamar Giladi, Robert Warren and H. Ronald Pulliam 2014. Probabilistic and Spatially Variable Niches Inferred from Demography. In Journal of Ecology, pp. 1-6, online publication.

Fraterrigo, J.M., Wagner, S. and Warren, R.J. II. 2014. Local-scale biotic interactions embedded in macroscale climate drivers suggest Eltonian noise hypothesis distribution patterns for an invasive grass. Ecology Letters. 17:1447-1454.

Warren, Robert J. II, Itamar Giladi and Mark A. Bradford, 2014. Competition as a Mechanism Structuring Mutualisms. Journal of Ecology 102:486-495

King, Joshua R., Robert J. Warren, and Mark A. Bradford. 2013. Social Insects Dominate Eastern US Temperate Hardwood Forest Macroinvertebrate Communities in Warmer Regions. PLOS ONE 8(10):e75843.

Warren, R.J. II, Bahn, V. and Bradford, M. 2013. Decoupling litter barrier and soil moisture influences on the establishment of an invasive grass. Plant and Soil. (DOI: 10.1007/s11104-012-1477-z)

Warren, R.J. II, Keiser, A., Ursell, T. and Bradford, M. 2013. Habitat, dispersal and propagule pressure control exotic plant infilling within an invaded range. Ecosphere. (DOI: 10.1890/ES12-00393.1)

Warren, Robert J. and Lacy Chick. 2013. Upward ant distribution shift corresponds with minimum, not maximum, temperature tolerance. Global Change Biology 19(7):2082-2088.

Jones, J.A., Creed, I.F., Hatcher, K.L., Warren, R.J., Adams, M.B., Benson, M.H. Boose, E., Brown, W.A. Campbell, J.L., Covich, A., Clow, D.W., Dahm , C.N., Elder, K., Ford, C.R., Grimm , N.B., Henshaw, D.L., Larson, K.L., Miles, E.S., Miles, K.M., Sebestyen, S.D., Spargo, A.T., Stone, A.B., Vose, J.M., Williams, M.W., 2012. Ecosystem Processes and Human Influences Regulate Streamflow Response to Climate Change at LTER Sites. BioScience. Vol. 62:4, April 2012

Kramer, Timothy D., Robert J. Warren II, Yaya Tang and Mark Bradford (2012) Grass Invasions Across a Regional Gradient are Associated with Declines in Belowground Carbon Pools (online document:

Tang Yaya, Robert Warren III, Timothy Kramer, and Mark Bradford (2012) Plant invasion impacts on arthropod abundance, diversity and feeding consistent across environmental and geographic gradients. Biological Invasions:1-13. Online Version DOI:

Warren, R.J, Giladi, I., Bradford, M.A. (2012) Environmental heterogeneity and interspecific interactions influence nest colonization by key seed-dispersing ants. Environmental Entomology, 41, 463-468.

Warren, Robert J. and Jeffrey K. Lake. 2012. Trait plasticity, not values, best corresponds with woodland plant success in novel and manipulated habitats. Journal of Plant Ecology 1-12.

Warren II, R. J., V. Bahn, T. D. Kramer, Y. Tang, and M. A. Bradford. 2011. Performance and reproduction of an exotic invader across temperate forest gradients. Ecosphere 2(2):art14. doi:10.1890/ES10-00181.1

Warren, R. J. II, V. Bahn, and M. A. Bradford. 2011. Temperature cues phenological synchrony in ant-mediated seed dispersal. Global Change Biology (Online First). doi: 10.1111/j.1365-2486.2010.02386.x.

Warren, R. J., D. K. Skelly, O. J. Schmitz, and M. A. Bradford. 2011. Universal ecological patterns in college basketball communities. PLoS ONE, 6(3): e17342.

Warren, R. J., II, Bradford, M.A., 2011, Ant colonization and coarse woody debris decomposition in temperate forests. Insectes Sociaux Vol 59:2, Nov. 19, 2011, DOI 10.1007/s00040-011-0208-4

Warren, Robert J., II, Bahn, V., and Bradford, M.A., 2011, The interaction between propagule pressure, habitat suitability and density-dependent reproduction in species invasion, Oikos: Synthesizing Ecology, November 2011,

Warren, Robert J., Justin P. Wright, Mark A. Bradford. 2011. The Putative Niche Requirements and Landscape Dynamics of Microstegium vimineum: an Invasive Asian Grass. Biological Invasions 13: 471-483

Warren, R. J. and M. A. Bradford. 2010. The shape of things to come: woodland herb niche contraction begins during recruitment in mesic forest microhabitat. Proceedings of the Royal Society B, doi:10.1098/rspb.2010.1886.

Warren, R. J. II, E. Mordecai. 2010. Soil moisture mediated interaction between Polygonatum biflorum and leaf spot disease. Plant Ecology, 209: 1-9.

Warren, R.J, and M.A. Bradford. 2010. Seasonal climate trends, the North Atlantic Oscillation and salamander abundance in the southern Appalachian mountain region. Journal of Applied Meteorology and Climatology. 49:1597-1603.

Warren, R.J. 2009. An experimental test of well-described vegetation patterns across slope aspects using woodland herb transplants and manipulated abiotic drivers. New Phytologist, 185: 1038-1049

Warren, R.J. 2008. Mechanisms driving understory evergreen herb distributions across slope aspects: as derived from landscape position. Plant Ecology. 198(2): 297-308.

Theses and Dissertations

Warren, Robert J.. 2007. Linking Understory Evergreen Herbaceous Distributions and Niche Differentiation Using Habitat-Specific Demography and Experimental Common Gardens. Ph.D. Dissertation. Athens, GA: University of Georgia