Role of nutrient cycling and herbivory in regulating periphyton communities in laboratory streams
- Oak Ridge National Laboratory, TN (United States)
- University of Louisville, KY (United States)
In this study the authors examined the role of nutrient cycling and herbivory in regulating stream periphyton communities. Population, community, and ecosystem-level properties were studied in laboratory stream channels that had nutrient inputs reduced compared to channels where ambient nutrient levels were maintained. They reduced nutrient inputs in four of eight channels by recirculating 90% of the flow, whereas the other four channels received once-through flow of spring water. They examined the interaction between herbivory and nutrients by varying the number of snails (Elimia clavaeformis) among streams with different nutrient input regimes. Reduction in nutrient input via recirculation resulted in lower concentrations of nutrients in the water but did not result in significant differences in biomass, carbon fixation, or algal taxonomic composition. However, herbivory had large effects on these characteristics by reducing biomass and areal rates of carbon fixation and simplifying periphyton taxonomy and physiognomy. Lower rates of nutrient input significantly affected characteristics associated with nutrient cycling. Streams with reduced nutrient inputs had lower periphyton nutrient contents, higher ratios of total:net uptake of P from water, and higher rates of phosphatase activity than streams with ambient nutrient inputs. However, the effects of reduced nutrient input on cycling characteristics were reduced or eliminated by intense herbivory.
- OSTI ID:
- 6913987
- Journal Information:
- Ecology; (United States), Journal Name: Ecology; (United States) Vol. 72:3; ISSN 0012-9658; ISSN ECOLAR
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
560300 -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
CARBON DIOXIDE FIXATION
ECOSYSTEMS
MINERAL CYCLING
NUTRIENTS
PHYTOPLANKTON
PLANKTON
PLANTS
PREDATOR-PREY INTERACTIONS
PRODUCTIVITY
STREAMS
SURFACE WATERS