Plant Ecology

, Volume 213, Issue 2, pp 315–326 | Cite as

Differential effects of herbivory and pathogen infestation on plant population dynamics

  • Annette KolbEmail author


Plants often interact with antagonists such as herbivores or pathogens. Negative effects on individual plant performance are widely documented, but less is known about whether such effects translate into effects on population viability. In temperate forests, important herbivores include deer. During 2006–2009, I compared vital rates and population growth rates (calculated using integral projection models) between fenced exclosures and grazed control areas, using the perennial herb Phyteuma spicatum as a model species. Deer caused the largest damage to flowering individuals, removing about 24% of all inflorescences and 13% of the above-ground biomass. Only few vital rates seemed to be negatively affected by deer (mainly seed production) and this did not translate into effects on population growth rate. Contrary to expectations, population growth rates tended to be lower in the fenced exclosures in 1 year. This was likely caused by high-pathogen infestation rates, which negatively affected the probability of adult survival and growth. Population growth rate was more sensitive to changes in these vital rates than to changes in seed production. In summary, the results of this demographic study show that grazing effects may be small for long-lived herbs, and that negative effects on vital rates such as seed production may not always translate into effects on population growth rate. The findings also illustrate that other antagonists such as pathogens may be of greater relative importance for differences in population performance than herbivores.


Deer grazing Forest herb Integral projection model Phyteuma spicatum Population growth rate Vital rates 



I thank Marion Ahlbrecht, Katharina Barsch, Dirk Enters, Dietrich Kolb, Silke Lehmann, Dorit Mersmann, Anja Schnorfeil, Anne Weber, and Christiane Weiner for research assistance, and Johan Dahlgren, Martin Diekmann, and Johan Ehrlén for discussion and comments on earlier versions of this manuscript. I thank the land owners for access to their forests and the administrative district Stade for the permit to work in the nature reserve “Im Tadel.” The University of Bremen provided financial support (ZF-No. 02/801/05).


  1. Augustine DJ, Frelich LE (1998) Effects of white-tailed deer on populations of an understory forb in fragmented deciduous forests. Conserv Biol 12:995–1004CrossRefGoogle Scholar
  2. Bermingham LH (2010) Deer herbivory and habitat type influence long-term population dynamics of a rare wetland plant. Plant Ecol 210:359–378CrossRefGoogle Scholar
  3. Bowers MA, Sacchi CF (1991) Fungal mediation of a plant-herbivore interaction in an early successional plant community. Ecology 72:1032–1037CrossRefGoogle Scholar
  4. Burdon JJ, Chilvers GA (1982) Host density as a factor in plant disease ecology. Annu Rev Phytopathol 20:143–166CrossRefGoogle Scholar
  5. Caswell H (2001) Matrix population models: construction, analysis, and interpretation, 2nd edn. Sinauer Associates, SunderlandGoogle Scholar
  6. Colling G, Matthies D (2004) The effects of plant population size on the interactions between the endangered plant Scorzonera humilis, a specialised herbivore, and a phyto-pathogenic fungus. Oikos 105:71–78CrossRefGoogle Scholar
  7. Côté SD, Rooney TP, Tremblay J-P, Dussault C, Waller DM (2004) Ecological impacts of deer overabundance. Annu Rev Ecol Evol Syst 35:113–147CrossRefGoogle Scholar
  8. Ellner SP, Rees M (2006) Integral projection models for species with complex demography. Am Nat 167:410–428PubMedCrossRefGoogle Scholar
  9. Farrington SJ, Muzika R-M, Drees D, Knight TM (2009) Interactive effects of deer herbivory on the population dynamics of American ginseng. Conserv Biol 23:719–728CrossRefGoogle Scholar
  10. Fuller RJ, Gill RMA (2001) Ecological impacts of increasing numbers of deer in British woodland. Forestry 74:193–199CrossRefGoogle Scholar
  11. Garve E (2004) Rote Liste und Florenliste der Farn- und Blütenpflanzen in Niedersachsen und Bremen–5. Fassung, Stand 1.3.2004. Informationsdienst Naturschutz Niedersachsen 24:1–76Google Scholar
  12. Gilbert GS (2002) Evolutionary ecology of plant diseases in natural ecosystems. Annu Rev Phytopathol 40:13–43PubMedCrossRefGoogle Scholar
  13. Hegland SJ, Rydgren K, Seldal T (2005) The response of Vaccinium myrtillus to variations in grazing intensity in a Scandinavian pine forest on the island of Svanøy. Can J Bot 83:1638–1644CrossRefGoogle Scholar
  14. Hegland SJ, Jongejans E, Rydgren K (2010) Investigating the interaction between ungulate grazing and resource effects on Vaccinium myrtillus populations with integral projection models. Oecologia 163:695–706PubMedCrossRefGoogle Scholar
  15. Knight TM (2004) The effects of herbivory and pollen limitation on a declining population of Trillium grandiflorum. Ecol Appl 14:915–928CrossRefGoogle Scholar
  16. Knight TM, Caswell H, Kalisz S (2009) Population growth rate of a common understory herb decreases non-linearly across a gradient of deer herbivory. For Ecol Manag 257:1095–1103CrossRefGoogle Scholar
  17. Kolb A (2005) Reduced reproductive success and offspring survival in fragmented populations of the forest herb Phyteuma spicatum. J Ecol 93:1226–1237CrossRefGoogle Scholar
  18. Kolb A (2008) Habitat fragmentation reduces plant fitness by disturbing pollination and modifying response to herbivory. Biol Conserv 141:2540–2549CrossRefGoogle Scholar
  19. Kolb A, Dahlgren JD, Ehrlén J (2010) Population size affects vital rates but not population growth rate of a perennial plant. Ecology 91:3210–3217PubMedCrossRefGoogle Scholar
  20. Kumar S, Shibata E (2007) Establishment and growth of coniferous seedlings in an altered forest floor after long-term exclusion of deer. J For Res 12:306–311CrossRefGoogle Scholar
  21. Maron JL, Crone E (2006) Herbivory: effects on plant abundance, distribution and population growth. Proc R Soc B 273:2575–2584PubMedCrossRefGoogle Scholar
  22. Martin TG, Arcese P, Scheerder N (2011) Browsing down our natural heritage: deer impacts on vegetation structure and songbird populations across an island archipelago. Biol Conserv 144:459–469CrossRefGoogle Scholar
  23. McGraw JB, Furedi MA (2005) Deer browsing and population viability of a forest understory plant. Science 307:920–922PubMedCrossRefGoogle Scholar
  24. Milner JM, Bonenfant C, Mysterud A, Gaillard J-M, Csányi S, Stenseth NC (2006) Temporal and spatial development of red deer harvesting in Europe: biological and cultural factors. J Appl Ecol 43:721–734CrossRefGoogle Scholar
  25. R Development Core Team (2010) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna.
  26. Rooney TP, Gross K (2003) A demographic study of deer browsing impacts on Trillium grandiflorum. Plant Ecol 168:267–277CrossRefGoogle Scholar
  27. Rooney TP, Waller DM (2003) Direct and indirect effects of white-tailed deer in forest ecosystems. For Ecol Manag 181:165–176CrossRefGoogle Scholar
  28. Russell FL, Zippin DB, Fowler NL (2001) Effects of white-tailed deer (Odocoileus virginianus) on plants, plant populations and communities: a review. Am Midl Nat 146:1–26CrossRefGoogle Scholar
  29. Schmidt M, Ewald J, Fischer A, von Oheimb G, Kriebitzsch W-U, Schmidt W, Ellenberg H (2003) Liste der in Deutschland typischen Waldgefäßpflanzen. Mitteilungen der Bundesforschungsanstalt für Forst- und Holzwirtschaft Hamburg 212:1–34Google Scholar
  30. Silvertown J, Franco M, Pisanty I, Mendoza A (1993) Comparative plant demography—relative importance of life-cycle components to the finite rate of increase in woody and herbaceous perennials. J Ecol 81:465–476CrossRefGoogle Scholar
  31. Snow AA, Whigham DF (1989) Costs of flower and fruit production in Tipularia discolor (Orchidaceae). Ecology 70:1286–1293CrossRefGoogle Scholar
  32. Springer YP (2009) Edaphic quality and plant-pathogen interactions: effects of soil calcium on fungal infection of a serpentine flax. Ecology 90:1852–1862PubMedCrossRefGoogle Scholar
  33. Syrjänen K, Lehtilä K (1993) The cost of reproduction in Primula veris: differences between two adjacent populations. Oikos 67:465–472CrossRefGoogle Scholar
  34. Wheeler BR (1997) Aspects of the ecology and conservation of the rare plant species Phyteuma spicatum L. (Campanulaceae) in the British Isles. Dissertation, University of SussexGoogle Scholar
  35. Wheeler BR, Hutchings MJ (2002) Phyteuma spicatum L. J Ecol 90:581–591CrossRefGoogle Scholar
  36. Witt JC, Webster CR (2010) Regeneration dynamics in remnant Tsuga canadensis stands in the northern Lake States: potential direct and indirect effects of herbivory. For Ecol Manage 260:519–525CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Vegetation Ecology and Conservation Biology, Institute of EcologyUniversity of BremenBremenGermany

Personalised recommendations