Nutrient availability and plant gender influences on the short-term compensatory response of Salix planifolia ssp planifolia to simulated leaf herbivory
G. Houle, Nutrient availability and plant gender influences on the short-term compensatory response of Salix planifolia ssp planifolia to simulated leaf herbivory, CAN J FORES, 29(12), 1999, pp. 1841-1846
Citations number
40
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
Males and females of dioecious plants often differ in their biochemistry, p
hysiology, morphology, and (or) ecology. For example, growth rates often ar
e higher for males than for females. Because the ability of plants to compe
nsate for herbivory frequently varies with growth rate, we may expect males
and females of dioecious plants to differ in their compensatory ability (h
ypothesis 1). However, environmental factors such as nutrient availability
may influence the expression of such a response (hypothesis 2). For example
, low nutrient availability may reduce growth rate and thus restrict compen
sation. To test these hypotheses, I cloned male and female genets of Salix
planifolia Pursh ssp. planifolia from a natural population in northeastern
Canada. I then submitted the plants of each sex to two levels of simulated
leaf herbivory in combination with two levels of nutrient availability. Con
trary to the first hypothesis, plant gender had no significant effect on th
e compensatory response to simulated leaf herbivory. However, nutrient avai
lability modulated the compensatory ability of plants of both sexes, theref
ore supporting hypothesis 2. Herbivory may thus be more detrimental to the
performance of S. planifolia individuals in low-nutrient environments, such
as on dunes or rock outcrops.