The restoration of sedge meadows: Seed viability, seed germination requirements, and seedling growth of Carex species

To better understand how to establish Carex species from seed in created an d restored wetlands, a series of experimental studies was conducted on Care x seed and seedlings. These studies included (1) the effect of seed age (1 to 18 months after collection) on viability and germination, (2) storage co nditions (+4, -4 or +4/-4 degrees C; wet or dry) on seed germination, (3) s oil moisture on seed germination, and (4) soil amendments (fertilizer, tops oil, and compost) on seedling recruitment and growth. Seeds of Carex specie s of several provenances would not germinate to any appreciable extent once they were more than six months old. For Carex aquatilis, germination could be increased by storing its seed at either 4 degrees C or -4 degrees C. Fo r Carex lacustris and Carex stricta, seed germination decreased significant ly, by about 50 to 100% in all 8 storage treatments. Germination of Carex s tipata seed was highest in 1 cm of standing water, and its seed did not ger minate in the driest soil moisture treatment. Carex stricta seed germinatio n was not affected very much by soil moistures. No Carex spp. were recruite d from seed in any of the field soil-amendment treatment plots. In both the greenhouse and field, the addition of compost, topsoil, and fertilizer inc reased the growth of Carex stricta In a greenhouse study, above ground, bel ow ground, and total dry mass increased linearly with the percent compost a dded. Our results suggest that the probability of establishing Carex spp. f rom seed in created and restored wetlands in the Upper Midwest would be max imized by using fresh seed, preferably seed produced earlier in the same gr owing season; by keeping soil moisture levels as high as possible; and by r aising the soil's organic matter content, if need be, through the use of su itable soil amendments to levels found in natural sedge meadows.