Invasive Species

Invasive Species


Byers, J. E.,  J. A. Blaze, A. C. Dodd, H. L. Hall, &. P. E. Gribben. 2023. Exotic asphyxiation: interactions between invasive species and hypoxia. Biological Reviews 98: 150-167. PDF

Kinney, K. A., L. M. Pintor, A. C. Mell, & J. E. Byers. 2023. Density-dependent predation and predator preference for native prey may facilitate an invasive crab’s escape from natural enemies. Biological Invasions 25: 2967-2976. doi: 10.1007/s10530-023-03085-5 PDF


Smith, R. S., J. Beauvais, & J. E. Byers. 2022. Traits of resident saltmarsh plants promote retention of range-expanding mangroves under specific tidal regimes. Estuaries and Coasts 45: 1422-1433. PDF


Krueger-Hadfield, S. A., J. E. Byers, G. Bonthond,R. Terada,F. Weinberger, & E. E. Sotka. 2021. Intraspecific diversity and genetic structure in the widespread macroalga Agarophyton vermiculophyllum. J. of Phycology 57(5): 1403-1410. PDF

Byers, J. E. 2021. Marine parasites and disease in the era of global climate change. Annual Review of Marine Science 13: 397-420. PDF

Firth, L. B., D. Harris, J.A. Blaze, M.P. Marzloff, A. Boyé, P.I. Miller, A. Curd, M. Vasquez, J.D. Nunn, N.E. O’Connor, A.M. Power, N. Mieszkowska, R.M. O’Riordan, M.T. Burrows, L.M. Bricheno, A.M. Knights, F.L.D. Nunes, F. Bordeyne, L.E. Bush, J. E. Byers, C. David, A.J. Davies, S.F. Dubois, H. Edwards, A. Foggo, L. Grant, J.A.M. Green, P.E. Gribben, F.P. Lima, D. McGrath, L.M.L.J. Noël, R. Seabra, C. Simkanin, S.J. Hawkins.  2021. Specific niche requirements underpin multidecadal range edge stability, but may introduce barriers for climate change adaptation.  Diversity and Distributions 27: 668-683. doi: 10.1111/ddi.13224. PDF

Smith, R. S.,J. A. Blaze, & J. E. Byers. 2021. Dead litter of resident species first facilitates and then inhibits sequential life stages of range-expanding species. Journal of Ecology 109: 1649-1664.  doi: 10.1111/1365-2745.13538.  (With cover). PDF


Gribben, P. E. and J. E. Byers. 2020. Comparative biogeography of marine invaders across their native and introduced ranges. Oceanography and Marine Biology: An Annual Review, 58: 395-440. PDF

Byers, J. E. 2020. Effects of climate change on parasites and disease in estuarine and nearshore environments. PLoS Biology 18(11): e3000743. PDF

Haram, L. E., E. E. Sotka, & J. E. Byers. 2020.  Effects of novel, non-native detritus on decomposition and invertebrate community assemblage. Marine Ecology Progress Series 643: 49-61. doi: 10.3354/meps13335. PDF

Smith, R. S.,J. A. Blaze, & J. E. Byers.  2020.  Negative indirect effects of hurricanes on recruitment of range-expanding mangroves. Marine Ecology Progress Series 644: 65-74.  doi: 10.3354/meps13351. PDF

Chen, E., J. A. Blaze, R. S. Smith, S. Peng, J. E. Byers.  2020.  Freeze-tolerance of poleward-spreading mangrove species weakened by soil properties of resident salt marsh competitor. Journal of Ecology 108: 1725-1737. doi: 10.1111/1365-2745.13350. PDF

Wasson, K., R. A. Fabian, S. Fork, J. Stanganelli, Z. Mize, K. Beheshti, R. Jeppesen, I. Jones, C. J. Zabin, S. Walker, S. C. Lummis, M. Emery, J. D. Moore, C. Endris, D. Jolette, & J. E. Byers. 2020. Multiple factors contribute to the spatially variable and dramatic decline of an invasive snail in an estuary where it was long-established and phenomenally abundant. Biological Invasions. 22: 1181–1202. doi: 10.1007/s10530-019-02172-w. PDF

Gooding, E. L.,  M. R. Kendrick, J. F. Brunson, P. R. Kingsley-Smith, A. E. Fowler, M. E. Frischer, & J. E. Byers. 2020.  Black gill increases the susceptibility of white shrimp, Penaeus setiferus (Linnaeus, 1767), to common estuarine predators. J. Experimental Marine Biology and Ecology 524: 151284. doi: 10.1016/j.jembe.2019.151284. PDF


Smith, R. S.,T. Z. Osborne, I. C. Feller, & J. E. Byers.  2019.  Detrital traits affect substitutability of a range-expanding foundation species across latitude. Oikos 128(9): 1367-1380. doi: 10.1111/oik.06149. PDF

McDowell, W. G. and J. E. Byers.  2019.  High abundance of a lone member of a functional guild gives an invasive species an outsized ecological role. Freshwater Biology 64: 577-586. doi: 10.1111/fwb.13243. PDF

Sotka, E. E. and J. E. Byers.  2019.  Not so fast. Promoting invasive species to enhance multifunctionality in a native ecosystem requires strong(er) scrutiny. Biological Invasions 21: 19-25. doi: 10.1007/s10530-018-1822-0.  PDF

Byers, J. E. and E. E. Sotka. 2019.  Promoting invasive species to enhance multifunctionality in a native ecosystem still requires strong(er) scrutiny. Biological Invasions 21(2): 277-280. doi: 10.1007/s10530-018-1851-8.  PDF

Hostert, L. E.,  L. M. Pintor, & J. E. Byers.  2019.  Sex, size and prey caloric value affects diet specialization and consumption of an invasive prey by a native predator.  Current Zoology 65(5): 499-507. doi: 10.1093/cz/zoy076. PDF

Kinney, K. A., L. M. Pintor, & J. E. Byers.  2019.  Does predator-driven, biotic resistance limit the northward spread of the non-native green porcelain crab, Petrolisthes armatusBiological Invasions 21: 245-260.  PDF


Haram, L. E., K. A. Kinney, E. E. Sotka, & J. E. Byers.  2018. Mixed effects of an introduced ecosystem engineer on the foraging behavior and habitat selection of predators.  EcologyPDF

Wright, J.T., Z. C. Holmes, & J. E. Byers.  2018.  Stronger positive association between an invasive crab and a native intertidal ecosystem engineer with increasing wave exposure.  Marine Environmental Research 142: 124-129. PDF

Smith, R. S., J. A. Blaze, T. Z. Osborne, & J. E. Byers.  2018. Facilitating your replacement? Ecosystem engineer legacy affects establishment success of an expanding competitor.  Oecologia 188(1): 251-262.  PDF

Gehman, A. M.*, R. J. Hall, & J. E. Byers. 2018. Host and parasite thermal ecology jointly determine the effect of climate warming on epidemic dynamics. Proceedings of the National Academy of Sciences 115(4): 744-749. doi: 10.1073/pnas.1705067115.  PDF   (*winner of ESA’s Aquatic Section Thomas M. Frost Award for Excellence in Graduate Research 2018)

Malek, J. C. and J. E Byers. 2018.  Responses of an oyster host (Crassostrea virginica) and its protozoan parasite (Perkinsus marinus) to increasing air temperature.  PeerJ 6:e5046.  doi: 10.7717/peerj.5046.  PDF


Keogh, C. L., O. Miura, T. Nishimura, & J. E. Byers.  2017.  The double edge to parasite escape: invasive host is less infected but more infectable.  Ecology 98(9): 2241-2247.  PDF

Malek, J. C. and J. E. Byers. 2017. The effects of tidal elevation on parasite heterogeneity and co-infection in the eastern oyster, Crassostrea virginica. Journal of Experimental Marine Biology & Ecology 494: 32-37.  PDF

Krueger-Hadfield, S. A., N. M. Kollars, A. E. Strand, J. E. Byers, S. J. Shainker, R. Terada, T. W. Greig, M. Hammann, D. C. Murray, F. Weinberger, & E. E. Sotka. (in press, 2017).  The identification of source and vector of a prolific marine invader.  Ecology and Evolution.

Gehman, A. M. and J. E. Byers2017. Non-native parasite enhances susceptibility of host to native predators.  Oecologia 183: 919–926.  PDF

Gehman, A. M., J. H. Grabowski, A. R. Hughes, D. L. Kimbro, M. F. Piehler, & J. E. Byers..  2017.  Predators, environment and host characteristics influence the probability of infection by an invasive castrating parasite.  Oecologia 183: 139–149. PDF

McDowell, W. G., W. H. McDowell, & J. E. Byers.  2017.  Mass mortality of a dominant invasive species in response to an extreme climate event: implications for ecosystem function.  Limnology and Oceanography 62: 177-188. PDF

Burks, R. L., J. Bernatis, J. E. Byers, J. Carter, C. W. Martin, W. G. McDowell, & J. van Dyke 2017. Identity, reproductive potential, distribution, ecology and management of invasive Pomacea maculata in the southern United States. In: Biology and management of invasive apple snails. Eds.: R.C. Joshi, R.H. Cowie & L.S. Sebastian. Philippine Rice Research Institute (PhilRice), Maligaya, Science City of Muñoz, Nueva Ecija 3119. p.293-333. PDF


Malek, J. C. and J. E. Byers. (in press, 2016).  Predator effects on host-parasite interactions in the eastern oyster, Crassostrea virginica.  Marine Ecology Progress SeriesPDF

Byers, J. E., Z. C. Holmes, & A. M. H. Blakeslee.  2016.  Consistency of trematode infection prevalence in host populations across large spatial and temporal scales. Ecology 97(7): 1643-1649. PDF

Krueger-Hadfield, S. A., N. M. Kollars, J. E. Byers, T. W. Greig, M. Hammann, D. C. Murray, C. J. Murren, A. E. Strand, R. Terada, F. Weinberger, & E. E. Sotka.  2016.  Invasion of novel habitats uncouples haplo-diplontic life cycles.  Molecular Ecology 25: 3801-3816. PDF

Kollars, N. M., J. E. Byers, & E. E. Sotka.   2016.  Invasive décor: An association between a native decorator worm and a non-native seaweed can be mutualistic.  Marine EcologyPDF

Keogh, C. L., M. E. Sanderson, & J. E. Byers.  2016.  Local adaptation to parasite selective pressure: comparing three congeneric co-occurring hosts. Oecologia 180(1): 137-147. doi:10.1007/s00442-015-3461-9PDF


Pintor, L. M. and J. E. Byers.  2015.  Do native predators benefit from non-native prey?  Ecology Letters 18: 1174-1180. PDF

Byers, J. E.,  R. S. Smith, J. M. Pringle, G. F. Clark, P. E. Gribben, C. L. Hewitt, G. J. Inglis, E. L. Johnston, G. M. Ruiz, J. J. Stachowicz, & M. J. Bishop.  2015. Invasion expansion: time since introduction best predicts global ranges of marine invaders.  Scientific Reports 5, 12436; doi: 10.1038/srep12436. PDF

Byers, J. E., A. J. Malek, L. E. Quevillon, I. Altman, & C.L. Keogh.  2015.  Opposing selective pressures decouple pattern and process of parasitic infection over small spatial scale.  Oikos 124(11): 1511-1519.  doi 10.1111/oik.02088. PDF

Kollars, N. M., S. A. Krueger-Hadfield, J. E. Byers, T. W. Greig, A. E. Strand, F. Weinberger, E. E. Sotka.  2015. Development and characterization of microsatellite loci for the haploid-diploid red seaweed Gracilaria vermiculophylla.  PeerJ 3:e1159.  doi 10.7717/peerj.1159. PDF

Pintor, L. M. and J. E. Byers.  2015.  Individual trait variation in a native predator affects its consumption of a novel, non-native prey.  Behavioral Ecology 26(3): 797-804. PDF

Bishop, M. J. and J. E. Byers. 2015.  Predation risk predicts use of a novel habitat. Oikos 124(9): 1225-1231.  doi: 10.1111/oik.01967. PDF


Wright, J. T., J. E. Byers, J. L. DeVore, & E. E. Sotka.  2014. Engineering or food? Mechanisms of facilitation by a habitat-forming invasive seaweed. Ecology 95(10): 2699-2706. PDF

Byers, J. E., R. S. Smith, H. W. Weiksel, & C. Y. Robertson.  2014. A non-native prey mediates the effects of a shared predator on an ecosystem service.  PLoS One 9(4): e93969. doi:10.1371/journal.pone.0093969. PDF

Thomsen, M. S., T. Wernberg, J. D. Olden, J. E. Byers, J. F. Bruno, B. R. Silliman, & D. R. Schiel.  2014. Forty years of experiments on invasive species: are study biases limiting our understanding of impacts?  Neobiota 22: 1-22.  doi: 10.3897/neobiota.22.6224. PDF

McDowell, W.G., A. J. Benson, & J. E. Byers. 2014.  Climate controls the distribution of an abundant invasive species: implications for future range expansion.  Freshwater Biology 59: 847-857. PDF

Thomsen, M. S., J. E. Byers, D. R. Schiel, J. F. Bruno, J. D. Olden, T. Wernberg, & B. R. Silliman 2014. Impacts of marine invaders on biodiversity depend on trophic position and functional similarity. Marine Ecology Progress Series 495: 39-47. PDF

Byers, J. E. and J.H. Grabowski.  2014. Soft-sediment communities.  In: Marine Community Ecology.  Eds.: M. D. Bertness, J. F. Bruno, B. R. Silliman & J. J. Stachowicz. Sinauer, p.227-249. PDF

Colautti, R.I., S.J. Franks, R.A. Hufbauer, P.M. Kotanen, M.E. Torchin, J. E. Byers, P. Pyšek, & O. Bossdorf.  2014. The global garlic mustard field survey (GGMFS): challenges and opportunities of a unique, large-scale collaboration for invasion biology. Neobiota 21: 29-47. PDF

Wonham, M. J., J. E. Byers, E. D. Grosholz, & B. Leung. 2013. Modeling the relationship between propagule pressure and invasion risk to inform policy and management. Ecological Applications 23(7): 1691-1706. PDF

Parker, J. D., M.E. Torchin, R.A. Hufbauer, N.P. Lemoine, C. Alba, D.M. Blumenthal, O. Bossdorf,  J. E. Byers, A.M. Dunn, R.W. Heckman, M. Hejda, V. Jarošík, A.R. Kanarek, L.B. Martin, S.E. Perkins, P. Pyšek, K. Schierenbeck, C. Schlöder, R. van Klinken, K.J. Vaughn, W. Williams, & L.M. Wolfe.  2013. Do invasive species perform better in their new ranges? Ecology 94(5): 985-994. PDF

Gribben, P. E., J. E. Byers, J. T. Wright & T. M. Glasby.  2013.  Positive versus negative effects of an invasive ecosystem engineer on different components of a marine ecosystem.  Oikos 122: 816-824. (Highlighted as an Editor’s Choice Manuscript). PDF

Byers, J. E., W.G. McDowell, S. Robertson, R. Haynie, L.M. Pintor, & S.B. Wilde. 2013. Climate and pH predict the potential range of the invasive apple snail (Pomacea insularum) in the southeastern United States.  PLoS ONE 8(2): e56812. doi:10.1371/journal.pone.0056812. PDF

Burfeind, D.D., K.A. Pitt, R.M. Connolly, & J. E. Byers.  2013. Performance of non-native species within marine reserves.  Biological Invasions 15: 17-28. PDF


Dunn, A.M., M.E. Torchin, M.J. Hatcher, P.M. Kotanen , D.M. Blumenthal,  J.E. Byers, C.A.C. Coon, V.M. Frankel, R.D. Holt, R.A. Hufbauer, A.R. Kanarek, K.A. Schierenbeck, L.M. Wolfe, & S.E. Perkins. 2012.  Indirect effects of parasites in invasions.  Functional Ecology 26: 1262-1274. PDF

Byers, J. E., P.E. Gribben, C. Yeager, & E. Sotka. 2012. Impacts of an abundant invasive ecosystem engineer within mudflats of the southeastern US coast. Biological Invasions 14: 2587-2600. PDF

Wright, J.T., P.E. Gribben, J. E. Byers, & K. Monro.  2012.  Invasive ecosystem engineer selects for different phenotypes of an associated native species. Ecology 93(6): 1262-1268. PDF

Blakeslee, A.M.H.,  I. Altman, A.W. Miller, J. E. Byers, C.E. Hamer, & G.M. Ruiz.  2012. Parasites and invasions: a biogeographic examination of parasites and hosts in native and introduced ranges.  J. of Biogeography 39: 609-622. PDF

Wright, J.T., J. E. Byers, L.P. Koukoumaftsis, & P.E. Gribben.  2012.  Differences in anti-predator traits of a native bivalve following invasion by a habitat-forming seaweed.  Marine & Freshwater Research 63: 246-250PDF


Canning-Clode, J., A.E. Fowler, J. E. Byers, J.T. Carlton, & G.M. Ruiz.  2011.  ‘Caribbean Creep’ chills out: climate change and marine invasive species.  PLoS ONE 6(12): e29657. PDF


Blakeslee, A.M.H., C.H. McKenzie, J.A. Darling, J. E. Byers, J.M. Pringle, & J. Roman. 2010. A hitchhiker’s guide to the Maritimes: anthropogenic transport facilitates long-distance dispersal of an invasive marine crab to Newfoundland. Diversity and Distributions 16(6): 879-891. PDF

Byers, J. E.,  P.E. Gribben, & J.T. Wright. 2010. Variable direct and indirect effects of a habitat-modifying invasive species on mortality of native fauna. Ecology 91(6): 1787-1798PDF

Wright, J.T.,  J. E. Byers, L.P. Koukoumaftsis, P.J. Ralph, & P.E. Gribben. 2010.  Native species behaviour mitigates the impact of habitat-forming invasive seaweed. Oecologia 163: 527-34. PDF


Blakeslee, A.M.H., C.L. Keogh, J. E. Byers, A.M. Kuris, K.D. Lafferty, & M.E. Torchin. 2009.  Differential escape from parasites by two competing introduced crabs. Marine Ecology Progress Series 393: 83-96. PDF

Gribben, P.E., J. E. Byers, M. Clements, L.A. McKenzie, P.D. Steinberg, & J.T. Wright. 2009.  Behavioural interactions between ecosystems engineers control community species richness. Ecology Letters 12(11): 1127-1136PDF

Brawley, S. H.,  J.A. Coyer, A.M.H. Blakeslee, G. Hoarau, L.E. Johnson, J. E. Byers, W.T. Stam, & J.L. Olsen. 2009.  Historical invasions of the intertidal zone of Atlantic North America associated with distinctive patterns of trade and emigration.  Proceedings of the National Academy of Sciences 106(20): 8239-8244. PDF

Freeman, A., J. Meszaros, & J. E. Byers.  2009. Poor phenotypic integration of blue mussel inducible defenses in environments with multiple predators.  Oikos 118: 758-766. PDF

Byers, J. E.  2009.  Invasive animals in marshes: Biological agents of change.  In: Human impacts on salt marshes: A global perspective. Eds.: Brian Silliman, Edwin Grosholz & Mark Bertness. University of California Press. pp. 41-56. PDF

Griffen, B. D. and J. E. Byers. 2009. Community impacts of two invasive crabs: the interactive roles of density, prey recruitment, and indirect effects.  Biological Invasions 11(4): 927-940. PDF

Byers, J. E.  2009.  Competition in Marine Invasions.  In: Biological invasions in marine ecosystems: Ecological, management, and geographic perspectives.  Eds.: Gil Rilov & Jeff Crooks. Springer-Verlag.  pp. 245-260. PDF


Blakeslee, A.M.H.,  J. E. Byers, & M.P. Lesser. 2008. Solving cryptogenic histories using host and parasite molecular genetics: the resolution of Littorina littorea’s North American origin. Molecular Ecology 17(16): 3684-3696. PDF

Hellmann, J.J., J. E. Byers, B.G. Bierwagen, & J.S. Dukes. 2008. Five potential consequences of climate change for invasive species. Conservation Biology 22(3): 534-543. PDF

Blakeslee, A.M.H. and J. E. Byers. 2008. Using parasites to inform ecological history: comparisons among three congeneric marine snails. Ecology 89(4): 1068-1078. PDF

Byers, J. E., A. Blakeslee, E. Linder, A. Cooper, & T. Maguire. 2008. Controls of spatial variation in the prevalence of trematode parasites infecting a marine snail. Ecology 89(2):439-451. PDF


Wood, C. L.*, J. E. Byers, K. Cottingham, I. Altman, M. Donahue, & A. Blakeslee. 2007. Parasites alter community structure. Proceedings National Academy of Sciences 104(22): 9335-39. [*winner of ESA’s Outstanding Undergraduate Student Research Award 2008] PDF

Tyrell, M.C. and J. E. Byers. 2007. Do artificial substrates favor nonindigenous fouling species over natives? Journal of Experimental Marine Biology and Ecology 342: 54-60. PDF


Freeman, A. and J. E. Byers.  2006.  Divergent induced responses to an invasive predator in marine mussel populations. Science 313 (5788): 831-833. PDF

Griffen, B. D. and J. E. Byers. 2006.  Intraguild predation reduces redundancy of predator species in multiple predator assemblage.  Journal of Animal Ecology 75: 959-966. PDF

Griffiths, J., M. Dethier, A. Newsom, J. E. Byers, J. Meyer, F. Oyarzun, & H. Lenihan. 2006. Invertebrate community responses to recreational clam digging. Marine Biology 149(6): 1489-1497. PDF

Byers, J. E. and J. M. Pringle. 2006. Going against the flow: retention, range limits and invasions in advective environments. Marine Ecology Progress Series 313: 27-41. PDF

Griffen, B. D. and J. E. Byers. 2006. Partitioning mechanisms of predator interference in different habitats. Oecologia 146(4): 608-614. [Correction for typo in Eq. 1 appears in: 147(1): 181]. PDF


Torchin, M.E., J. E. Byers, & T. Huspeni.  2005.  Differential parasitism of native and introduced snails: replacement of a parasite fauna. Biological Invasions 7(6): 885-894. PDF

Reusink, J., H. Lenihan, A. Trimble, K. Heiman, F. Micheli, J. E. Byers, & M. Kay.  2005.  Introduction of non-native oysters: ecosystem effects and restoration implications.  Annual Review of Ecology, Evolution, and Systematics 36: 643-689. PDF

Byers, J. E.  2005. Quantifying geographical variation in physiological performance to address the absence of invading species. Ecoscience 12(3): 358-365. (Special volume: Spatial and temporal dynamics of biological invasions). PDF

Noonburg, E. G. and J. E. Byers. 2005.  More harm than good: when invader vulnerability to predators enhances impact on native species.  Ecology 86(10): 2555-2560. PDF

Byers, J. E.  2005.  Marine reserves enhance abundance but not competitive impacts of a harvested nonindigenous species.  Ecology 86(2): 487–500. (With cover). PDF

Meyer, J. J. and J. E. Byers. 2005. As good as dead? Sublethal predation facilitates lethal predation on an intertidal clam. Ecology Letters 8(2): 160-166. PDF


Byers, J. E. and E. G. Noonburg. 2003.  Scale dependent effects of biotic resistance to biological invasion. Ecology 84(6): 1428-1433. PDF


Byers, J. E.  2002.  Physical habitat attribute mediates biotic resistance to non-indigenous species invasion.  Oecologia 130(1): 146-156. PDF

Byers, J. E., S. Reichard, J. Randall, I. Parker, C. Smith, W. Lonsdale, I. Atkinson, T. Seasted, M. Williamson, E. Chornesky, & D. Hayes. 2002. Directing research to reduce the impacts of nonindigenous species.  Conservation Biology 16(3): 630-640. PDF

Byers, J. E.  2002. Impact of non-indigenous species on natives enhanced by anthropogenic alteration of selection regimes. Oikos 97(3): 449-458. PDF


Byers, J. E. and L. Goldwasser.  2001.  Exposing the mechanism and timing of impact of non-indigenous species on native species.  Ecology 82(5): 1330-1343. PDF


Byers, J. E.  2000. Competition between two estuarine snails: implications for invasions of exotic species.  Ecology 81(5): 1225-1239. PDF

Byers, J. E. 2000.  Effects of body size and resource availability on dispersal in a native and a non-native estuarine snail.  Journal of Experimental Marine Biology & Ecology 248(2): 133-150. PDF

Byers, J. E. 2000.  Differential susceptibility to hypoxia aids estuarine invasion.  Marine Ecology Progress Series 203: 123-132.PDF


Byers, J. E.  1999. The distribution of an introduced mollusc and its role in the long-term demise of a native confamilial species.  Biological Invasions 1(4): 339-353. PDF

Parker, I.,  D. Simberloff, M. Lonsdale, K. Goodell, M. Wonham, P. Kareiva, M. Williamson, B. Von Holle, P. Moyle, J. E. Byers, & L. Goldwasser.  1999.  Impact: toward a framework for understanding the ecological effects of invaders.  Biological Invasions 1(1): 3-19.PDF