Plant Interactions with Herbivores


Plants are eaten by a tremendous array of herbivores, including almost half of known insect species. Although herbivores consume most plants to some degree, many plants are also relatively well defended, and herbivore populations are often limited by predators. The net result of these processes is that the extent of herbivory, and the strength of its effects on plant populations and ecosystem processes, are highly variable. Herbivores strongly influence plants in aquatic environments, productive environments and environments with nutritious, poorly defended plants or few predators. Effects of herbivores can also be accentuated through positive feedbacks between herbivory and soil resources, in which herbivore‐mediated changes in plant community composition accelerate or decelerate nutrient cycling. Although research on herbivory has focused primarily on natural systems, few of these systems are free of human influence. Humans dramatically change plant–herbivore relationships by removing predators, increasing plant resource availability and moving both plants and herbivores around the globe.

Key concepts

  • Plants defend themselves effectively, using a combination of chemical defences and physical defences and tolerance.

  • Plant defence theory aims to explain variation among species and ecosystems in the types and amounts of plant defence.

  • In addition to plant defences, the extent of herbivory is limited by predation, which can greatly reduce herbivore abundance.

  • Despite plant defences and predation, herbivores often have strong effects on plants.

  • Positive feedbacks between plant resources, plant traits and herbivores can increase the influence of herbivores on plants and ecosystems.

  • Humans dramatically alter plant–herbivore dynamics by moving plants and herbivores, reducing the abundance of predators, increasing nutrient availability and changing the spatial distribution of plant communities.

Keywords: grazing; herbivory; plant defence; plant productivity and diversity; predation

Figure 1.

Pine beetle effects on a lodgepole pine forest in Colorado, USA. Photo by Erik Hardy.

Figure 2.

(a) Musk ox on tundra in Kangerlussuaq, Greenland (photo by Heidi Steltzer). (b) Impala in tropical savanna in Laikipia, Kenya (photo by David Augustine).



Abbott KC and Dwyer G (2007) Food limitation and insect outbreaks: complex dynamics in plant‐herbivore models. Journal of Animal Ecology 76: 1004–1014.

Abraham KF, Jefferies RL and Alisauskas RT (2005) The dynamics of landscape change and snow geese in mid‐continent North America. Global Change Biology 11: 841–855.

Agrawal AA (2004) Resistance and susceptibility of milkweed: competition, root herbivory, and plant genetic variation. Ecology 85: 2118–2133.

Agrawal AA (2007) Macroevolution of plant defense strategies. Trends in Ecology & Evolution 22: 103–109.

Agrawal AA, Lau JA and Hamback PA (2006) Community heterogeneity and the evolution of interactions between plants and insect herbivores. Quarterly Review of Biology 81: 349–376.

Allen RB, Payton IJ and Knowlton JE (1984) Effects of ungulates on structure and species composition of the Urewera forests as shown by exclosures. New Zealand Journal of Ecology 7: 119–130.

Anderson VJ and Briske DD (1995) Herbivore‐induced species replacement in grasslands: is it driven by herbivory tolerance or avoidance? Ecological Applications 5: 1014–1024.

Andow DA (1991) Vegetational diversity and arthropod population response. Annual Review of Entomology 36: 561–586.

Augustine DJ and Mcnaughton SJ (1998) Ungulate effects on the functional species composition of plant communities: herbivore selectivity and plant tolerance. Journal of Wildlife Management 62: 1165–1183.

Augustine DJ and Mcnaughton SJ (2004) Regulation of shrub dynamics by native browsing ungulates on East African rangeland. Journal of Applied Ecology 41: 45–58.

Augustine DJ and Mcnaughton SJ (2006) Interactive effects of ungulate herbivores, soil fertility, and variable rainfall on ecosystem processes in a semi‐arid savanna. Ecosystems 9: 1242–1256.

Aunapuu M, Dahlgren J, Oksanen T et al. (2008) Spatial patterns and dynamic responses of arctic food webs corroborate the exploitation ecosystems hypothesis (EEH). American Naturalist 171: 249–262.

Bigger DS and Marvier MA (1998) How different would a world without herbivory be? A search for generality in ecology. Integrative Biology 1: 60–67.

Blossey B and Hunt‐Joshi TR (2003) Belowground herbivory by insects: influence on plants and aboveground herbivores. Annual Review of Entomology 48: 521–547.

Blumenthal D (2005) Interrelated causes of plant invasion. Science 310: 243–244.

Bokdam J and Gleichman J (2000) Effects of grazing by free‐ranging cattle on vegetation dynamics in a continental north‐west European heathland. Journal of Applied Ecology 37: 415–431.

Borer ET, Seabloom EW, Shurin JB et al. (2005) What determines the strength of a trophic cascade? Ecology 86: 528–537.

Bryant JP, Chapin FS and Klein DR (1983) Carbon nutrient balance of boreal plants in relation to vertebrate herbivory. OIKOS 40: 357–368.

Carson WP and Root RB (2000) Herbivory and plant species coexistence: community regulation by an outbreaking phytophagous insect. Ecological Monographs 70: 73–99.

Cebrian J (1999) Patterns in the fate of production in plant communities. American Naturalist 154: 449–468.

Chase JM, Leibold MA, Downing AL and Shurin JB (2000) The effects of productivity, herbivory, and plant species turnover in grassland food webs. Ecology 81: 2485–2497.

Cingolani AM, Noy‐Meir I and Diaz S (2005) Grazing effects on rangeland diversity: a synthesis of contemporary models. Ecological Applications 15: 757–773.

Coley PD and Barone JA (1996) Herbivory and plant defenses in tropical forests. Annual Review of Ecology and Systematics 27: 305–335.

Coley PD, Bryant JP and Chapin FS (1985) Resource availability and plant antiherbivore defense. Science 230: 895–899.

Crawley M (1983) Herbivory: the dynamics of plant–animal interactions. Berkeley: University of California Press.

Crawley MJ (1989) Insect herbivores and plant‐population dynamics. Annual Review of Entomology 34: 531–564.

Cyr H and Pace ML (1993) Magnitude and patterns of herbivory in aquatic and terrestrial ecosystems. Nature 361: 148–150.

DeFries RS, Foley JA and Asner GP (2004) Land‐use choices: balancing human needs and ecosystem function. Frontiers in Ecology and the Environment 2: 249–257.

Dewalt SJ, Denslow JS and Ickes K (2004) Natural‐enemy release facilitates habitat expansion of the invasive tropical shrub Clidemia hirta. Ecology 85: 471–483.

Ehrlich PR and Raven PH (1964) Butterflies and plants: a study in coevolution. Evolution 18: 586–608.

Feeny P (1976) Plant apparency and chemical defence. In: Wallace J and Mansell RL (eds) Biochemical Interactions between Plants and Insects, 10th edn, pp. 1–40. New York: Plenum Press.

Fine PVA, Mesones I and Coley PD (2004) Herbivores promote habitat specialization by trees in amazonian forests. Science 305: 663–665.

Frank DA (2008) Evidence for top predator control of a grazing ecosystem. OIKOS 117: 1718–1724.

Frank DA, Mcnaughton SJ and Tracy BF (1998) The ecology of the earth's grazing ecosystems: comparing the Serengeti and Yellowstone. BioScience 48: 513–521.

Gatehouse JA (2002) Plant resistance towards insect herbivores: a dynamic interaction. New Phytologist 156: 145–169.

Gruner DS, Smith JE, Seabloom EW et al. (2008) A cross‐system synthesis of consumer and nutrient resource control on producer biomass. Ecology Letters 11: 740–755.

Hairston NG, Smith FE and Slobodkin LB (1960) Community structure, population control, and competition. American Naturalist 94: 421–425.

Hawkes CV and Sullivan JJ (2001) The impact of herbivory on plants in different resource conditions: a meta‐analysis. Ecology 82: 2045–2058.

Herms DA and Mattson WJ (1992) The dilemma of plants: to grow or defend. Quarterly Review of Biology 67: 283–335.

Hillebrand H, Gruner DS, Borer ET et al. (2007) Consumer versus resource control of producer diversity depends on ecosystem type and producer community structure. Proceedings of the National Academy of Sciences of the USA 104: 10904–10909.

Hobbs NT (1996) Modification of ecosystems by ungulates. Journal of Wildlife Management 60: 695–713.

Hofland‐Zijlstra J and Berendse F (2009) The effect of nutrient supply and light intensity on tannins and mycorrhizal colonization in Dutch heathland ecosystems. Plant Ecology 201: 661–675. DOI 10.1007/s11258‐11008‐19554‐11253.

Jaenike J (1990) Host specialization in phytophagous insects. Annual Review of Ecology and Systematics 21: 243–273.

Karban R and Kuc J (1999) Induced resistance against pathogens and herbivores: an overview. In: Agrawal AA, Tuzun S and Bent E (eds) Induced Plant Defenses Against Pathogens and Herbivores, pp. 1–16. St. Paul, MN: APS Press.

Karban R, Agrawal AA and Mangel M (1997) The benefits of induced defenses against herbivores. Ecology 78: 1351–1355.

Keane RM and Crawley MJ (2002) Exotic plant invasions and the enemy release hypothesis. Trends in Ecology & Evolution 17: 164–170.

Lucas PW, Turner IM, Dominy NJ and Yamashita N (2000) Mechanical defences to herbivory. Annals of Botany 86: 913–920.

Maron JL and Crone E (2006) Herbivory: effects on plant abundance, distribution and population growth. Proceedings of the Royal Society B: Biological Sciences 273: 2575–2584.

McInnes PF, Naiman RJ, Pastor J and Cohen Y (1992) Effects of moose browsing on vegetation and litter of the boreal forest, Isle Royale, Michigan, USA. Ecology 73: 2059–2075.

McNaughton SJ (1978) Serengeti ungulates: feeding selectivity influences the effectiveness of plant defense guilds. Science 199: 806–807.

McNaughton SJ, Oesterheld M, Frank DA and Williams KJ (1989) Ecosystem‐level patterns of primary productivity and herbivory in terrestrial habitats. Nature 341: 142–144.

Mduma SAR, Sinclair ARE and Hilborn R (1999) Food regulates the Serengeti wildebeest: a 40‐year record. Journal of Animal Ecology 68: 1101–1122.

Milchunas DG and Lauenroth WK (1993) Quantitative effects of grazing on vegetation and soils over a global range of environments. Ecological Monographs 63: 327–366.

Milchunas DG, Sala OE and Lauenroth WK (1988) A generalized‐model of the effects of grazing by large herbivores on grassland community structure. American Naturalist 132: 87–106.

Moran VC, Hoffmann JH and Zimmermann HG (2005) Biological control of invasive alien plants in South Africa: necessity, circumspection, and success. Frontiers in Ecology and the Environment 3: 77–83.

Oksanen L, Fretwell SD, Arruda J and Niemela P (1981) Exploitation ecosystems in gradients of primary productivity. American Naturalist 118: 240–261.

Parker JD, Burkepile DE and Hay ME (2006) Opposing effects of native and exotic herbivores on plant invasions. Science 311: 1459–1461.

Pastor J, Cohen Y and Hobbs NT (2006) The roles of large herbivores in ecosystem nutrient cycles. In: Danell K, Bergstrom R, Duncan P and Pastor J (eds) Large Herbivore Ecology, Ecosystem Dynamics, and Conservation, pp. 289–325. Cambridge, UK: Cambridge University Press.

Rhoades DF and Cates RG (1976) Towards a general theory of plant anti‐herbivore chemistry. In: Wallace J and Mansell RL (eds) Biochemical Interactions between Plants and Insects, 10th edn, pp. 168–213. New York: Plenum Press.

Ritchie ME, Tilman D and Knops JMH (1998) Herbivore effects on plant and nitrogen dynamics in oak savanna. Ecology 79: 165–177.

Schmitz OJ, Hamback PA and Beckerman AP (2000) Trophic cascades in terrestrial systems: a review of the effects of carnivore removals on plants. American Naturalist 155: 141–153.

Shurin JB, Gruner DS and Hillebrand H (2006) All wet or dried up? Real differences between aquatic and terrestrial food webs. Proceedings of the Royal Society B: Biological Sciences 273: 1–9.

Stamp N (2003) Out of the quagmire of plant defense hypotheses. Quarterly Review of Biology 78: 23–55.

Strauss SY and Agrawal AA (1999) The ecology and evolution of plant tolerance to herbivory. Trends in Ecology & Evolution 14: 179–185.

Strong DR (1992) Are trophic cascades all wet: differentiation and donor‐control in speciose ecosystems. Ecology 73: 747–754.

Terborgh J, Lopez L, Nunez P et al. (2001) Ecological meltdown in predator‐free forest fragments. Science 294: 1923–1926.

Walling LL (2000) The myriad plant responses to herbivores. Journal of Plant Growth Regulation 19: 195–216.

Wise MJ and Abrahamson WG (2007) Effects of resource availability on tolerance of herbivory: a review and assessment of three opposing models. The American Naturalist 169: 443–454.

Young TP, Stanton ML and Christian CE (2003) Effects of natural and simulated herbivory on spine lengths of Acacia drepanolobium in Kenya. OIKOS 101: 171–179.

Yudelman M, Ratta A and Nygaard D (1998) Pest Management and Food Production: Looking to the Future. Washington DC: International Food Policy Research Institute.

Further Reading

Danell K, Bergström R, Duncan P and Pastor J (eds) (2006) Large Herbivore Ecology, Ecosystem Dynamics and Conservation. Cambridge, UK: Cambridge University Press.

Gange AC and Brown VK (eds) (1997) Multi‐trophic Interactions in Terrestrial Systems. Oxford: Blackwell Science.

Hughes RN (ed.) (1993) Diet Selection: An Interdisciplinary Approach to Foraging Behaviour. Oxford: Blackwell Scientific Publications.

Karban R and Baldwin IT (1997) Induced Responses to Herbivory. London: Chapman and Hall.

Olff H, Brown VK and Drent RH (eds) (1999) Herbivores: Between Plants and Predators. Oxford: Blackwell Science.

Schmitz OJ (2008) Herbivory from individuals to ecosystems. Annual Review of Ecology Evolution and Systematics 39: 133–152.

Schoonhoven LM, van Loon JJA and Dicke M (2005) Insect‐Plant Biology. Oxford: Oxford University Press.

Strauss SY and Irwin RE (2004) Ecological and evolutionary consequences of multi‐species plant–animal interactions. Annual Review of Ecology Evolution and Systematics 35: 435–466.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Blumenthal, Dana, and Augustine, David(Sep 2009) Plant Interactions with Herbivores. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0003203.pub2]