Regeneration and Establishment Strategies of Emergent Macrophytes

Publisher Website
Google Scholar
Abstract
The covariation within, and the relationship between, seven juvenile (seed/seedling) and thirteen adult traits of twenty-five species of emergent macrophytes occurring along the Ottawa River, Canada, is described. Contrary to r-K selection, but in accordance with C-S-R theory, there was no association between these two sets of traits. The major axis of variation within the juvenile traits consisted, at one end, of large, slowly germinating seeds with seedlings possessing a low relative growth rate, and at the other end of small, rapidly germinating seeds with seedlings possessing a high relative growth rate. The regeneration strategies of these species are interpreted as consisting of fugitive vs. stress-tolerant juveniles. The adult traits showed two major trends. The largest was associated with the ability to occupy space and consisted of correlated variation in above-ground biomass, canopy diameter, rhizome thickness and rhizome or stolon length, this trend is interpreted as consisting of fugitive vs. competitive adults. A subordinate trend consisted of an uncoupling of height from above-ground biomass and was associated with the ''leafless'' morphology of a subset of species; this trend was related to environments in deeper water but having infertile soil and was interpreted as a stress-tolerant stragegy. These trends in trait variation were found to be related to environmental gradients of soil fertility and water depth.