Algal Periphyton Growth on Nutrient‐Diffusing Substrates: An in situ Bioassay
- 1 April 1985
- Vol. 66 (2) , 465-472
- https://doi.org/10.2307/1940395
Abstract
Differences in nutrient limitation for dominant species within an algal periphyton community were determined using additions of N and P supplied by nutrient—diffusing artificial substrates. Sealed clay flowerpots were filled with 2% agar and one of nine nutrient treatments (all combinations of K2HPO4 at 0.0, 0.05, and 0.5 mol/L with NaNO3 at 0.0, 0.05, and 0.5 mol/L). The pots were submerged at 0.5 m depth in Douglas Lake, Michigan, and diffused N and P to their outer surfaces in proportion to internal concentrations. After 51 d the pots were scraped and analyzed for attached algae. Total algal biomass as chlorophyll a on the pots ranged from 0.17 ± 0.02 (SE) mg/cm2 for pots without added nutrients to 15.7 ± 2.0 mg/cm2 for pots with K2HPO4 at 0.05 mol/L and NaNO3 at 0.5 mol/L. chlorophyll a on pots containing just P (0.05, 0.5 mol/L) increased 6— to 10—fold over controls. The diatoms Epithemia adnata and Rhopalodia gibba and the blue—green alga Anabaena increased significantly on the P—only pots; these species are suspected of N—fixing capability. Chlorophyll a on pots containing just N (0.05 mol/L) increased 1.5— to 2—fold, though this increase was nonsignificant; Achnanthes minutissima, Gomphonema tenellum, and Cocconeis placentula showed enhanced growth on these pots. Combinations of N and P caused heavy growth of the filamentous alga Stigeoclonium tenue. Naviculoid diatoms were also most abundant on the N + P pots. Average nutrient levels in Douglas Lake during the study were: NH3, 2.02 μmol/L; NO3, 0.44 μmol/L; and PO4, 0.06 μmol/L. The low ambient concentrations of both N and P, together with results of the periphyton bioassay, indicate that the two nutrients may jointly limit overall growth, and that the form of growth limitation differs by species within the periphyton community.This publication has 14 references indexed in Scilit:
- Assessment of factors limiting growth rate of Oscillatoria agardhii in hypertrophic Lake Wolderwijd, 1978, by use of physiological indicators1Limnology and Oceanography, 1982
- Nutrient enrichment of seagrass beds in a rhode island coastal lagoonMarine Biology, 1981
- The composition and ecology of periphyton communities in freshwaters. II. Inter-relationships between water chemistry, phytoplankton populations and periphyton populations in a shallow lake and associated experimental reservoirs (‘Lund tubes’)British Phycological Journal, 1981
- Periphytic Community Response to Chronic Nutrient Enrichment by a Reservoir DischargeEcology, 1980
- Effects of N:P atomic ratios and nitrate limitation on algal growth, cell composition, and nitrate uptake 1Limnology and Oceanography, 1978
- Enhancement of Autotrophic Production by Nutrient Addition in a Coastal Rainforest Stream on Vancouver IslandJournal of the Fisheries Research Board of Canada, 1978
- Evolution of Phosphorus Limitation in LakesScience, 1977
- Zur Entwicklungsgeschichte der EpithemiaceenEpithemia, Rhopalodia undDenticula (Diatomophyceae) und ihre vermutlich symbiotischen Sph roidk rperÖsterreichische botanische Zeitschrift, 1977
- Seasonal growth in Laminaria longicruris: Relations with dissolved inorganic nutrients and internal reserves of nitrogenMarine Biology, 1977
- Fine structure of an unusual cytoplasmic inclusion in the diatom genus,RhopalodiaProtoplasma, 1965