Response of periphytic algae to gradients in nitrogen and phosphorus in streamside mesocosms

Rier, ST; Stevenson, RJ

HERO ID

4543774

Reference Type

Journal Article

Year

2006

HERO ID 4543774
In Press No
Year 2006
Title Response of periphytic algae to gradients in nitrogen and phosphorus in streamside mesocosms
Authors Rier, ST; Stevenson, RJ
Journal Hydrobiologia
Volume 561
Issue 1
Page Numbers 131-147
Abstract In this study we manipulated both nitrogen and phosphorus concentrations in stream mesocosms to develop quantitative relationships between periphytic algal growth rates and peak biomass with inorganic N and P concentrations. Stream water from Harts Run, a 2nd order stream in a pristine catchment, was constantly added to 36 stream-side stream mesocosms in low volumes and then recirculated to reduce nutrient concentrations. Clay tiles were colonized with periphyton in the mesocosms. Nutrients were added to create P and N concentrations ranging from less than Harts Run concentrations to 128 mu g SRP l(-1) and 1024 mu g NO3-N l(-1)supercript stop. Algae and water were sampled every 3 days during colonization until periphyton communities reached peak biomass and then sloughed. Nutrient depletion was substantial in the mesocosms. Algae accumulated in all streams, even streams in which no nutrients were added. Nutrient limitation of algal growth and peak biomass accrual was observed in both low P and low N conditions. The Monod model best explained relationships between P and N concentrations and algal growth and peak biomass. Algal growth was 90% of maximum rates or higher in nutrient concentrations 16 mu g SRP l(-1) and 86 mu g DIN l(-1). These saturating concentrations for growth rates were 3-5 times lower than concentrations needed to produce maximum biomass. Modified Monod models using both DIN and SRP were developed to explain algal growth rates and peak biomass, which respectively explained 44 and 70% of the variance in algal response.
Doi 10.1007/s10750-005-1610-6
Wosid WOS:000236380500011
Url http://link.springer.com/10.1007/s10750-005-1610-6
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword periphyton; diatoms; nutrient limitation; Monod model; growth rates; peak biomass