Production of epibenthic salt marsh algae: Light and nutrient limitation1

作者：Van Raalte Charlene D., Iván Valiela, T. M. · 发表于：Limnology and Oceanography · 年份：1976 · DOI：10.4319/lo.1976.21.6.0862 · 被引用次数：132 · 研究领域：Coastal wetland ecosystem dynamics、Marine and coastal plant biology、Constructed Wetlands for Wastewater Treatment

Epibenthic algal production was measured in Great Sippewissett Marsh, Falmouth, Massachusetts, in plots treated with two levels of a mixed fertilizer and with urea or phosphate. Production, which followed a consistent seasonal pattern with short‐lived peaks in spring and fall, was increased by the highest dosage of mixed fertilizer but not by the other treatments. Fertilization also increased production of the marsh grasses. Algal production at the marsh surface was limited due to shading by the grass canopy. The production rate decreased with increasing biomass of the grasses. To separate the effects of light and nutrients in the treated areas, additional small plots were enriched with three levels of nitrogen (suspected as the limiting nutrient) and provided with three levels of canopy cover cross‐classified to the nitrogen treatments. Shading by the grasses reduced, while fertilization with nitrogen significantly increased, production. When the grasses were dormant, prediction from a model of epibenthic production based on limitation by light compared well with observed measurements. The predicted production rate was higher than that observed during the growing season of the grasses. In the plots receiving the highest doses of mixed fertilizer the added nutrients compensated for the light limitation, since the discrepancy between predicted and observed values was smaller than in the control plots.