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Research article2000Peer reviewed

Tolerance of Gentianella campestris in relation to damage intensity: an interplay between apical dominance and herbivory

Huhta, AP; Lennartsson, T; Tuomi, J; Rautio, P; Laine, K

Abstract

Meristem allocation models suggest that the patterns of compensatory regrowth responses following grazing vary, depending on (i) the number of latent meristems that escape from being damaged, and (ii) the activation sensitivity of the meristems in relation to the degree of damage. We examined the shape of compensatory responses in two late-flowering populations (59 degrees 20'N and 65 degrees 45'N) of the field gentian. Plants of equal initial sizes were randomly assigned to four treatment groups with 0, 10, 50 and 75% removal of the main stalk. The plants were clipped before flowering, and their performance was studied at the end of the growing season. The northern population showed a linear decrease in shoot biomass and fecundity with increasing biomass removal, while the response in the southern population was quadratic with maximum performance at the damage level of 50% clipping. This nonlinear shape depended upon the activation sensitivity of dormant meristems in relation to their position along the main stem. The highest plant performance was achieved by inflicting intermediate damage which induced regrowth from basally located meristems. In contrast, the topmost branches took over the dominance role of the main stem after minor apical damage (10% clipping). Consequently, the breakage of apical dominance is a necessary precondition of vigorous regrowth in this species. However, compensation in the field gentian is unlikely to be a mere incidental by-product of apical dominance. The ability to regrow from basally located meristems that escape from being damaged by grazing may well be a sign of adaptation to moderate levels of shoot damage.

Keywords

apical dominance; Gentianella; grazing tolerance; herbivory; meristem allocation; overcompensation; shoot architecture

Published in

Evolutionary Ecology
2000, Volume: 14, number: 4-6, pages: 373-392

      SLU Authors

    • Lennartsson, Tommy

      • Department of Conservation Biology, Swedish University of Agricultural Sciences

    UKÄ Subject classification

    Evolutionary Biology
    Botany
    Ecology

    Publication identifier

    DOI: https://doi.org/10.1023/A:1011028722860

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/101831