PARENT SESSION
Contributed Oral Session 96: Restoration and Adaptive Management: Fresh and Salt Water Wetlands; Deer
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 516 D, Level 5, Palais des congrès de Montréal
The role of seed arrival and seed germination in Carex recolonization of hydrologically restored prairie wetlands.
Kettenring, Karin*,1, Galatowitsch, Susan2, 1 kett0044@umn.edu, St. Paul, MN2 University of Minnesota, St. Paul, MN
ABSTRACT- Landscape level processes (including seed dispersal) and site levels factors (like seed germination) drive plant recolonization post-disturbance. In the prairie region of the mid-Continental U.S., plant recolonization in hydrologically restored wetlands occurs through natural processes; little emphasis has been placed on accelerating succession through seeding or planting of native species. While some plants recolonize quickly, the Carex spp., plants common in natural prairie wetlands, are not returning readily to restorations. We examined whether the recolonization of Carex is determined by seed arrival or germination limitations. In a seed arrival study, we compared Carex seed abundance in the seed rain of restored versus natural wetlands, versus other species in the restoration seed rain, and with the extant vegetation on-site and in nearest neighbor wetlands. To examine the role of Carex seed germination limitation in sedge meadow zones, we conducted a field germination experiment in restored and natural wetlands. In the seed arrival study, we found that Carex seeds were generally absent from the seed rain in restorations while annual weeds were abundant. In the germination experiment, we found that while seed germination was rare in natural wetlands (<1%), germination was abundant in restorations (often greater than 25%). We found the highest germination in plots where seeds were stratified prior to a spring sowing and in plots that were immediately adjacent to the water line. Our findings indicate that seed availability limits recolonization of Carex in restored wetlands in the highly fragmented prairie landscape. However, this limitation can be overcome through direct seeding of Carex with an emphasis on appropriate seed pretreatment, timing of sowing, and soil moisture conditions.
Key words: prairie pothole wetland restoration, Carex, seed germination, seed dispersal