Wave disturbance on lakeshores and the within-lake distribution of Ontario's Atlantic coastal plain flora

Although water level fluctuations may explain the persistence of Atlantic coastal plain species in certain Georgian Bay lakes, they cannot explain the within-lake distribution of this flora. To test whether the within-lake distribution of these species was correlated with disturbance from waves, 25 transects were quantitatively sampled along an exposure gradient in Axe Lake, Ontario. The proportion of Atlantic coastal plain species in a transect increased significantly with exposure (p < 0.01). Total frequency of Atlantic coastal plain species reached a maximum at an intermediate level of exposure. Analysis of substrate samples showed that the exposure gradient is a multivariate gradient including not only biomass removal by waves, but sorting of the shoreline substrate. The coarse, nutrient poor sites on exposed shores may allow the persistence of Atlantic coastal plain species in at least two different ways. Their physiological tolerance limits may be narrowly specialized on exposed shorelines. Alternatively, their physiological tolerances may include a broad range of shoreline types, but competition restricts them to those sites least suitable for other species.

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Water-Level Changes in Aquifers of the Atlantic Coastal Plain, Predevelopment to 2000

Scientific Investigations Report ◽

10.3133/sir20075247 ◽

2008 ◽

Cited By ~ 3

Author(s):

Vincent T. dePaul ◽

Donald E. Rice ◽

Otto S. Zapecza

Keyword(s):

Water Level ◽

Coastal Plain ◽

Atlantic Coastal Plain ◽

Water Level Changes ◽

Atlantic Coastal

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The effect of growing season length and water level fluctuations on growth and survival of two rare and at risk Atlantic Coastal Plain flora species, Coreopsis rosea and Hydrocotyle umbellata

Canadian Journal of Botany ◽

10.1139/b06-158 ◽

2007 ◽

Vol 85 (2) ◽

pp. 119-131 ◽

Cited By ~ 1

Author(s):

Jennifer M. Lusk ◽

Edward G. Reekie

Keyword(s):

At Risk ◽

Water Level ◽

Coastal Plain ◽

Growing Season ◽

Atlantic Coastal Plain ◽

Water Level Fluctuations ◽

Transplant Experiment ◽

Growth And Survival ◽

Growing Season Length ◽

Dam Reservoirs

This study examined variables that may be limiting rare species of Nova Scotia’s Coastal Plain flora to determine why they have not expanded to other lakeshores, including dam reservoirs with appropriate slope and substrate, and to determine how reservoir management could improve habitat quality. A transplant experiment was conducted to examine whether variables related to growing season (establishment time, position on shoreline, and water-level fluctuation) were limiting two at-risk species, Coreopsis rosea Nutt. (Pink Tickseed) and Hydrocotyle umbellata L. (Water-pennywort). Establishment time as well as timing and duration of flooding were found to limit both species. Unseasonable flooding and later establishment had similar effects in reducing biomass. The contribution of time spent above water to the final biomass was 2–3.4 times greater than time spent below water. At reservoirs, earlier spring draw down would reduce flood stress, while opening the dam during periods of high precipitation would avoid plant damage due to unseasonable flooding. Exposure of the lower shoreline for 49–71 d or greater would benefit H. umbellata, and exposure of the upper shoreline for 100–112 d or greater would benefit C. rosea. To conserve current habitat, we must also minimize disturbances to watersheds affecting natural fluctuations of occupied lakes.

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