TY - JOUR
T1 - The relative importance of shading and nutrients on algal production in subtropical streams
AU - Mosisch, T.D.
AU - Bunn, John
AU - Davies, Peter
PY - 2001
Y1 - 2001
N2 - 1. We used artificial substrata in forested and open streams in South-East Queensland, Australia, to determine the relative importance of shading from riparian vegetation and of nutrients on periphyton growth, and whether nitrogen and/or phosphorus limited algal productivity.2. Nutrient-diffusing substrata consisting of agar enriched with N, P and N + P, and controls without nutrients, were deployed in duplicate at 15 sites in headwater streams with riparian canopy cover ranging from 0 to 88%.3. Shading was the over-riding factor controlling periphyton biomass accrual on the artificial substrata, with nutrients playing a relatively minor role. Microscopic examination of periphyton scrapings; taken after 7 weeks revealed that diatoms dominated on the artificial substrata in shaded streams, whereas filamentous green algae dominated the algal assemblage in the more open canopy streams.4. Whilst nutrients had little effect on the accrual of algal biomass compared with riparian shading, there was evidence that nitrogen, and not phosphorus, stimulated periphyton production in streams with sufficient light.
AB - 1. We used artificial substrata in forested and open streams in South-East Queensland, Australia, to determine the relative importance of shading from riparian vegetation and of nutrients on periphyton growth, and whether nitrogen and/or phosphorus limited algal productivity.2. Nutrient-diffusing substrata consisting of agar enriched with N, P and N + P, and controls without nutrients, were deployed in duplicate at 15 sites in headwater streams with riparian canopy cover ranging from 0 to 88%.3. Shading was the over-riding factor controlling periphyton biomass accrual on the artificial substrata, with nutrients playing a relatively minor role. Microscopic examination of periphyton scrapings; taken after 7 weeks revealed that diatoms dominated on the artificial substrata in shaded streams, whereas filamentous green algae dominated the algal assemblage in the more open canopy streams.4. Whilst nutrients had little effect on the accrual of algal biomass compared with riparian shading, there was evidence that nitrogen, and not phosphorus, stimulated periphyton production in streams with sufficient light.
U2 - 10.1046/j.1365-2427.2001.00747.x
DO - 10.1046/j.1365-2427.2001.00747.x
M3 - Article
SN - 0046-5070
VL - 46
SP - 1269
EP - 1278
JO - Freshwater Biology
JF - Freshwater Biology
ER -