Effects of water level management on water chemistry and primary production of boreal marshes in northern Manitoba, Canada

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dc.contributor.supervisor Goldsborough, Gordon (Biological Sciences) en
dc.contributor.author Watchorn, Kristen Elise
dc.date.accessioned 2011-01-31T18:43:38Z
dc.date.available 2011-01-31T18:43:38Z
dc.date.issued 2011-01-31T18:43:38Z
dc.identifier.uri http://hdl.handle.net/1993/4399
dc.description.abstract This experiment manipulated water levels in boreal marshes within the Saskatchewan River Delta, a 9500 km2 region in northern Canada. Water levels in three wetland cells were lowered in a partial drawdown by a mean of 0.32 m. Water clarity, nutrient concentrations, and periphyton nutrient limitation were measured over the summer preceding and the summer following manipulation. The water levels of three adjacent control wetlands were not manipulated. Lowering wetland water levels reduced the wind velocity necessary to resuspend bottom sediments, which led to increases in turbidity, dissolved organic carbon, and concentrations of organic and inorganic nitrogen and phosphorus. Prior to drawdown, wetland periphyton communities were limited by nitrogen or co-limited by nitrogen and phosphorus. The input of nutrients from the sediment resulted in a shift from nutrient deficiency to nutrient sufficiency. Periphyton and phytoplankton production increased in response to the nutrient input. Increased turbidity, nutrient concentrations, and algal production were correlated with depth, rather than being inherent to the drawdown condition. Other water level manipulation studies have found that a reflood after a period of total drawdown caused a pulse of nutrients leaching from decomposing litter. This work suggests that these changes may not require complete drying out of sediments, or the input of large amounts of litter from drowned annual mudflat species, but rather can occur when depths are shallow enough that sediments are more frequently resuspended by wind. These findings have implications for future management of these marshes for waterfowl and muskrat production. en
dc.format.extent 3721025 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject wetlands en
dc.subject marshes en
dc.subject Summerberry Marsh en
dc.subject water chemistry en
dc.subject primary production en
dc.subject algae en
dc.subject macrophytes en
dc.title Effects of water level management on water chemistry and primary production of boreal marshes in northern Manitoba, Canada en
dc.type info:eu-repo/semantics/masterThesis
dc.type master thesis en_US
dc.degree.discipline Biological Sciences en
dc.contributor.examiningcommittee Robinson, Gordon (Biological Sciences) Markham, John (Biological Sciences) Wrubleski, Dale (Ducks Unlimited Canada) en
dc.degree.level Master of Science (M.Sc.) en
dc.description.note February 2011 en

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