Seed dispersal, germination and seedling growth of six helophyte species in relation to water‐level zonation

Abstract

SUMMARY 1. Seed dispersal, germination, and seedling growth characteristics of six helophyte species. Iris pseudacorus, Phalaris arundinacea, Phragmites australis, Typha angustifolia, T. latifolia and Scirpus lacustris, were investigated in relation to their water‐level zonation. 2. The experiments demonstrated a large variation in these characteristics between the species. 3. Propagule floating capacities range from < 1 h (S. lacustris) to > 1000 h (I. pseudacorus). 4. Seed germination in a water‐level gradient revealed two groups with respect to germination percentage ‐ exposed soil species (I. pseudacorus, Phalaris arundinacea, Phragmites australis) and submerged soil species (T. angustifolia, T. latifolia). 5. There were two contrasting types of seedling growth response to submergence and exposure: one group of species formed longest leaves under exposed conditions (Phalaris arundinacea, Phragmites australis, I. pseudacorus), and the other under submerged conditions (S. lacustris, T. latifolia, T. angustifolia). 6. The results suggest that early life‐history characteristics of the species relate to their locations in the riparian zonation: Phalaris arundinacea and Iris pseudacorus at the higher end, Phragmites australis intermediate, and Typha spp. and Scirpus lacustris at the lower end. Species occurring at lower locations show adaptations to (periodical) flooding of the soil (submersed germination and growth), while those from higher locations require prolonged exposed soil conditions to germinate and to survive the establishment stage.

Water-level fluctuations affect macrophyte richness in floodplain lakes

“…In lakes with small water-level fluctuations, drawdown may not occur. Drawdown strongly affects macrophyte composition, because drawdown is a prerequisite for successful germination and survival of various macrophytes (Keddy & Constabel, 1986;Smits et al, 1989;Coops & Van der Velde, 1995;Bonis & Grillas, 2002). In addition, disturbances caused .…”

Distribution patterns of a marsh vegetation metacommunity in relation to habitat configuration

“…This evaluation was reinforced by the species' individual characteristics. Phragmites australis is the most widespread species in the area, and it is also distributed within a pond in many of the ecological zones created by the water level, although its optimum occupation is the intermediate zone (Coops & Van der Velde 1995). P. australis is dispersed by wind and water, thus implying short-and long-distance vegetative and seed propagules dispersal (Fér & Hrou dová 2009 (Clevering & Lissner 1999).…”

Ecologische opvolging van plasbermen langs het Kanaal Brussel-Schelde, het Kanaal Charleroi-Brussel en het Kanaal Leuven-Dijle

“…grote en kleine lisdodde zich vestigen onder de waterlijn terwijl bv. riet en gele lis een droogvallende oever nodig hebben (Coops & Van Der Velde, 1995 De vooroever wordt bij voorkeur aangelegd met stortstenen of schanskorven, eerder dan met damplanken, wegens de hogere habitatdiversiteit. Voor de opvulling van de schanskorven geniet een grof kaliber van stenen de voorkeur, zonder verdere afdichting met bv.…”