Effects of water regime and competition on the establishment of a native sedge in restored wetlands

Published source details Budelsky R.A. & Galatowitsch S.M. (2000) Effects of water regime and competition on the establishment of a native sedge in restored wetlands. Journal of Applied Ecology, 37.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Remove vegetation that could compete with planted non-woody plants: freshwater wetlands Action Link
	Actively manage water level before/after planting non-woody plants: freshwater wetlands Action Link
	Directly plant non-woody plants: freshwater wetlands Action Link

Remove vegetation that could compete with planted non-woody plants: freshwater wetlands

A replicated, paired, controlled, before-and-after study in 1995–1997 in three recently excavated wet basins in Minnesota, USA (Budelsky & Galatowitsch 2000) found that weeding to remove competitors had no significant effect on survival of planted lake sedge Carex lacustris, but that effects on sedge abundance and height depended on other factors. The study generally does not report data for the comparisons in this summary. In each of three years, the survival rate of planted sedges was statistically similar in weeded and unweeded plots. The effect of weeding on sedge above-ground biomass, stem density and height depended on time since planting, elevation and/or water regime. For example, in all three years, weeding increased sedge biomass/m² in higher/drier plots but had no significant effect in lower, wetter plots. The average height of sedge shoots was lower in weeded than unweeded plots in the first year, but there was no significant difference between treatments in the second and third years. Methods: Forty-eight 5-m² plots were established, in 12 sets of four, across three wet basins (same as in Study 2). In May 1995, nursery-reared lake sedge was planted into each bare plot (10 or 45 plants/plot). Twenty-four plots (2 plots/set) were weeded (colonizing plants removed) throughout the study. The plots were situated at four different elevations, and each basin had a different water regime (falling, stable or rising through each growing season). Vegetation was surveyed through the 1995, 1996 and 1997 growing seasons.

(Summarised by: Nigel Taylor)
Actively manage water level before/after planting non-woody plants: freshwater wetlands

A controlled, before-and-after study in 1995–1997 in three recently excavated wet basins in Minnesota, USA (Budelsky & Galatowitsch 2000) found that the effect of simulating a naturally falling water level on survival, abundance and height of planted lake sedge Carex lacustris varied across time and/or environmental conditions. For example, in the first year after planting, sedge survival was lower under a falling water regime (82%) than under a rising water regime (97%). Water regime did not significantly affect survival rates in the second and third year after planting. In contrast, sedge biomass and stem density were not significantly increased by a falling water regime in the first year after planting (e.g. falling: 20; stable: 29; rising: 57 g/m² biomass) but were higher under a falling water regime by the third year (e.g. biomass falling: 953; stable: 536; rising: 573 g/m² biomass). In the third year, sedges in plots under a falling regime were at least as tall (average: 55–100 cm; maximum: 88–158 cm) as sedges under a stable or rising regime (average: 27–102 cm; maximum: 54–147 cm). Methods: The study used three wet basins (same as in Study 3), each of which was managed with a different water regime: falling, stable or rising throughout the growing season. The falling regime was most similar to natural conditions in local depressional wetlands (deepest flooding at start of growing season). In May 1995, nursery-reared lake sedge was planted into 48 bare, 5-m² plots (16 plots/basin; 10 or 45 plants/plot). The plots were situated at four different elevations, and half of the plots in each basin were weeded (colonizing plants removed) throughout the study. Vegetation was surveyed through the 1995, 1996 and 1997 growing seasons.

(Summarised by: Nigel Taylor)
Directly plant non-woody plants: freshwater wetlands

A replicated, before-and-after study in 1995–1997 in three recently excavated wet basins in Minnesota, USA (Budelsky & Galatowitsch 2000) reported >37% survival of lake sedge Carex lacustris in each of the three years after planting, and increases in sedge biomass, density and height over time. In the first growing season after planting, the sedge survival rate ranged from 37% in the wettest plots to 95% in the driest. In the next two growing seasons, the average survival rate across all plots was ≥95%. Amongst variation related to planting density, water regime, elevation and weeding treatments (see Actions: Actively manage water level after planting and Remove vegetation that could compete with planted vegetation), there were significant increases over time in sedge biomass (from 12–81 g/m² after one growing season to 272–1,160 g/m² after three growing seasons), density (from <20 stems/m² when planted to 143–219 stems/m² after three growing seasons) and average height (from <35 cm when planted to 88–102 cm after three growing seasons). Maximum height also increased, but this was not statistically tested (<80 cm when planted; 139–158 cm after three growing seasons). Methods: In May 1995, nursery-reared lake sedge was planted into 48 bare, 5-m² plots (10 or 45 plants/plot) across three wet basins (same as in Study 10). Each basin was managed with a different water regime: falling, stable or rising throughout the growing season. The plots were situated at four different elevations, and half were weeded (colonizing plants removed) throughout the study. Vegetation was surveyed through the 1995, 1996 and 1997 growing seasons.

(Summarised by: Nigel Taylor)