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

Abstract

To better understand how to establish Carex species from seed in created and restored wetlands, a series of experimental studies was conducted on Carex seed and seedlings. These studies included (1) the effect of seed age (1 to 18 months after collection) on viability and germination, (2) storage conditions (+4, -4 or +4/-4°C; wet or dry) on seed germination, (3) soil moisture on seed germination, and (4) soil amendments (fertilizer, topsoil, and compost) on seedling recruitment and growth. Seeds of Carex species 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°C or -4°C. For Carex Iacustris and Carex stricta, seed germination decreased significantly, by about 50 to 100% in all 8 storage treatments. Germination of Carex stipata seed was highest in 1 cm of standing water, and its seed did not germinate in the driest soil moisture treatment. Carex stricta seed germination was not affected very much by soil moistures. No Carex spp. were recruited from seed in any of the field soil-amendment treatment plots. In both the greenhouse and field, the addition of compost, topsoil, and fertilizer increased the growth of Carex stricta. In a greenhouse study, above ground, below ground, and total dry mass increased linearly with the percent compost added. Our results suggest that the probability of establishing Carex spp. from seed in created and restored wetlands in the Upper Midwest would be maximized by using fresh seed, preferably seed produced earlier in the same growing season; by keeping soil moisture levels as high as possible; and by raising the soil's organic matter content, if need be, through the use of suitable soil amendments to levels found in natural sedge meadows.

Formation of tussocks by sedges: effects of hydroperiod and nutrients

“…Although sedge meadows are typically nutrient-poor, groundwater-influenced systems (Kurtz et al 2007), C. stricta responded to N þ P addition (realistic loading rate; Neely andBaker 1989, Goolsby et al 1999) by increasing leaf, tussock, and total productivity, tussock volume, maximum leaf length, inflorescence production, and adventitious root cover. These findings corroborate increased biomass of C. stricta following nutrient addition in greenhouse and microcosm experiments (Van Der Valk et al 1999, Wetzel and Van der Valk 2005, Gallagher 2009), as well as increased C. stricta leaf growth in response to nutrient-rich storm water in a field study (Lawrence 2010). Increased biomass production under high-nutrient conditions suggests that C. stricta sequesters nitrogen and phosphorus while capturing more carbon.…”

A Paleoecological Perspective on Wetland Restoration

“…An underestimate of seedbank species composition may also result from differences in the duration of seed viability among the seeds of the different wetland plant taxa (Price et al 2010). For example, van der Valk et al (1999) demonstrated that the seeds of several species of Carex lose their viability (ability to geminate) in less than 1 year and may be poorly represented in seedling emergence studies compared to seeds that possess greater viability over longer time spans. Given that variable results have been generated using different methods it may be appropriate to utilize both seedling emergence and mechanical separation studies depending on the scope of the study (ter Heerdt et al 1996).…”

Effect of nitrogen and phosphorus on tissue nutrition and biomass of freshwater wetland plant in Sanjiang Plain, Northeast China

“…are typical in wetland, and previous studies have focused on the external factors of germination of Carex spp. (Budelsky and Galatowitsch, 1999;Van Der Valk et al, 1999) and the hydro-chemical range of C. lasiocarpa (Gorham, 1950). And there were some studies that analyzed the life history and the methane emissions and oxidation from freshwater marsh of C. lasiocarpa (Bedfod et al, 1988;Ding et al, 2004).…”