PARENT SESSION
Wednesday, August 9, 8:00-11:30 am
COS 52 - Restoration ecology I: aquatic and riparian ecosystems
L-3, Lobby Level, Cook Convention Center
Presiders: B Clinton
Restoring Carex diversity to prairie wetlands.
Kettenring, Karin*,1, Galatowitsch, Susan1, 1 University of Minnesota, St. Paul, MN
ABSTRACT- In prairie wetlands, plant recolonization in most hydrologically restored wetlands occurs through natural processes. While some plants recolonize quickly, the Carex spp., the signature species of the seasonally flooded zone, often do not return to restorations. Recent studies found that Carex are seed availability limited in restorations and that Carex propagules should be introduced to overcome this limitation. To aid in Carex revegetation efforts, we conducted a series of dormancy breaking and germination experiments in growth chambers. Of the eight species evaluated in light experiments, only two species germinated readily in the dark (C. stipata, C. brevior) and germination in all species was inhibited by far red light. These findings indicate that in restorations, Carex seeds should be sown early in restorations before the establishment of plant canopies, including cover crops, and should be broadcast on the soil surface. We also determined the stratification lengths required for dormancy break and the temperatures suitable for Carex seed germination. Species performances in these experiments were summarized with a Seed Regeneration Index (SRI) as a means of comparing the relative ease with which species regenerate from seed. The 14 species evaluated fell into two distinct groups according to their SRI. Species with a low SRI (low seed viability, strong dormancy, and narrow germination requirements) are of most concern to restorationists. A stratification treatment allows all species to germinate faster to higher percentages across a wider range of temperatures and we recommend the strategic use of stratification for species with a low SRI.
Key words: wetland restoration, prairie pothole wetlands, Carex