FACTORS AFFECTING SEED GERMINATION OF ELEOCHARIS CELLULOSA AND RHYNCOSPORA TRACYI FROM THE NORTHERN EVERGLADES

• Published in: Wetlands (Wilmington, N.C.) N.C.), 2006-06, Vol.26 (2), p.368-375
• Main Authors: Leeds, Jennifer A., Newman, Susan, Smith, Stephen M.
• Format: Article
• Language: English
• Subjects: allelochemicals; Allelopathy; Aquatic plants; Biological activity; cattail allelopathy; Cladium; Cladium jamaicense; CONTENTS; ecological restoration; Eleocharis; Eleocharis cellulosa; Eleocharis spp; Environmental restoration; Everglades; Germination; Indigenous plants; Indigenous species; Marshes; Microbial activity; Microorganisms; Nutrients; Nymphaea odorata; phosphorus; Plant communities; Plant extracts; Rhynchospora; Rhynchospora tracyi; Rhyncospora spp; Seed germination; seed viability; Seeds; soil nutrients; soil phosphorus; Soil surfaces; Soil temperature; Soils; Transition zone; Typha; viability; Wetlands
• ISSN: 0277-5212; 1943-6246
• DOI: 10.1672/0277-5212(2006)26[368:FASGOE]2.0.CO;2

The re-establishment of native plant communities, in particular the re-creation of ridge (sawgrass dominated; Cladium jamaicense) and slough (Eleocharis spp. and Nymphaea odorata) habitat, is a significant component of Everglades restoration. Two wetland species indicative of pristine slough habitats are Eleocharis cellulosa and Rhynchospora tracyi. This study conducted controlled experiments to examine three factors affecting seed germination of native slough species: 1) seed viability and the affect of burial length, 2) soil phosphorus (P) concentrations, and 3) allelopathic properties of cattail (Typha spp.). Two soil P levels (high and low) and two seed burial durations (three and five months) were chosen to represent field conditions to which these species are exposed. Allelopathic properties were determined using extracts from cattail plants. Eleocharis germination significantly decreased in high P soil concentrations (>500 mg/kg) compared to low P soil, independent of seed burial length as well as decreased germination between control (de-ionized water) and high concentration cattail extracts. For Rhynchospora, seed germination was significantly reduced between the three-month and five-month burial lengths regardless of nutrient levels. There were also significant reductions in seed germination upon exposure to cattail extracts as a result of allelopathic compounds. The seed germination results could be influenced by localized site aspects associated with high soil P causing increased microbial activity, which subsequently degraded seed viability. Additionally, dense cattail stands reduce light and temperature at the soil surface adversely affecting germination. Germination appears to be inhibited by a combination of factors indicative of high nutrient marsh areas. Therefore, germination and adult population re-establishment may be more successful in transition zones found between enriched and un-enriched marsh areas.