Cf. Dormann et al., Competition and herbivory during salt marsh succession: the importance of forb growth strategy, J ECOLOGY, 88(4), 2000, pp. 571-583
1 Despite much debate about their importance, only a few field studies have
evaluated the intensity of competition and herbivory.
2 Artemisia maritima, Atriplex portulacoides and Plantago maritima, three p
lant species which are common in European temperate salt marshes, were tran
splanted into different successional stages (15, 30 and 45 years old) of a
temperate salt marsh. Biomass of each transplant was measured as the respon
se variable to treatments that manipulated competition and the level of her
bivory.
3 All species were shown to be negatively influenced by both competition an
d herbivory, with competition being in general of greater importance than h
erbivory. No change could be detected during succession in the intensity of
either competition or herbivory. Their combined impact, however, increased
over succession for Atriplex, although no trend was observed for the other
two species.
4 Both biomass and allocation patterns reflected further adaptations of the
se salt-tolerant species to environmental stress and biotic interactions pr
esent in the salt marsh. Plantago, which is the best adapted to salinity, w
as shown to be markedly affected by competition and herbivory. Atriplex sho
wed less response to herbivory and little response to competition, to which
it is well adapted. The grazing-deterrent Artemisia was influenced by herb
ivory only as a seedling.