PARENT SESSION
Contributed Oral Session 121: Freshwater Wetlands
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal
Minor water level differences affect seedling survival, growth and competitive performance of eight wetland plants.
Fraser, Lauchlan*,1, 2, Karnezis, Jason1, Miletti, Tara1, 1 University of Akron, Akron, Ohio, USA2 Thompson Rivers University, Kamloops, British Columbia, Canada
ABSTRACT- Our objective was to investigate the survival, biomass accumulation and competitive performance of eight wetland plant species under different water levels in controlled microcosms. In the greenhouse, two-week-old seedlings from eight species (Carex lurida, Carex tribuloides, Elymus virginicus, Juncus tenuis, Lythrum salicaria, Phalaris arundinacea, Rumex orbiculatus, and Verbesina alternifolia) were randomly assigned to one of five water level treatments (-6, -4, -2, 0, +2 cm relative to the soil surface) and two competition treatments (phytometer P. arundinacea present and absent) and allowed to grow for six months. Species included 3 perennial sedges, 2 perennial grasses, and 2 perennial and 1 annual forbs. All of the species had their lowest biomass and lowest survivorship at water levels greater than 0 cm. Biomass accumulation differed by plant form (sedges>forbs>grasses). Of the eight plants tested, L. salicaria (purple loosestrife), one of the two invasive non-native species tested, had the highest biomass at all water levels. The competitive hierarchy remained consistent across water levels, with L. salicaria, P. arundinacea and R. orbiculatus all ranking high with respect to competitive performance. However, competitive performance values were significantly reduced at the +2 cm water level treatment.
Key words: plant ecology, competitive performance, wetland, Lythrum salicaria