Induced Defense: Herbivory on Juvenile vs. Adult Growth Stages of Trees

  • Dietland Müller-Schwarze


Plants contain “plant secondary metabolites” (PSMs) that confer resistance against herbivores and pathogens. The largest classes of PSMs are phenolics, terpenoids, and alkaloids. We distinguish constitutive and induced chemical defenses. The first occur in an entire plant or some of its parts as normal constituents, the latter are formed in response to herbivory or some other trauma to the plant. In some cases mere clipping induces defenses, in others additional factors, such as those in saliva of a herbivore are essential. Some northern trees such as green alder or paper birch respond to browsing by mammals such as snowshoe hares by growing adventitious shoots that are richer in PSMs than older twigs (Bryant 1981). These new shoots represent the juvenile-type growth form, while the older twigs on the tree or shrub are of the adult-type growth form. The fresh shoots with induced PSMs are avoided by hares for 1–3 years. In our area, quaking aspen, Populus tremuloides, that is growing back after cutting by beavers is more heavily defended during its first few years of regrowth (Basey et al. 1990).


Growth Form Data Sheet Insect Herbivory Adventitious Shoot Leaf Size 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Basey JM, Jenkins SH, Busher PE (1990) Food selection by beavers in relation to inducible defenses of populus tremuloides. Oikos 59:57–62CrossRefGoogle Scholar
  2. Bryant JP (1981) Phytochemical deterrence of snowshoe hare browsing by adventitious shoots of four Alaskan trees. Science 213:889–890CrossRefPubMedGoogle Scholar
  3. Fredrickson EL, Estell RE, Remmenga MD (2007) Volatile compounds on the leaf surface of intact and regrowth tarbush (Flourensia cernua DC) canopies. J Chem Ecol 33:1867–1875CrossRefPubMedGoogle Scholar
  4. Kessler A, Baldwin IT (2002) Plant responses to insect herbivory: The emerging molecular analysis. Ann Rev Plant Biol 53:299–328CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Dietland Müller-Schwarze
    • 1
  1. 1.College of Environmental Science and ForestryState University of New York-SyracuseSyracuseUSA

Personalised recommendations