Factors Affecting the Contribution by Epiphytic Algae to the Primary Productivity of an Oligotrophic Freshwater Lake

Abstract

A diatom-dominated population of epiphytic algae was studied in an oligotrophic lake to determine the factors which limit epiphyte growth and to measure their contribution to primary productivity. Algae were collected from plants growing at four sites in Lake George, N.Y., during the spring, summer, and fall of 1974. Samples were taken from 3 m, corresponding to the depth at which macrophytes were most productive. Algae exhibited an optimum temperature for H 14 CO 3 - uptake at 30 C, although the summer littoral lake temperature ranged from 18 to 25 C. Light saturation occurred at an intensity of 8,608 lux, approximating the environmental intensity at the depth from which algae were taken. Epiphytes exhibited their maximum photosynthetic capacity of 0.6 mg of carbon fixed/m 2 of macrophyte surface area per h in the early afternoon in mid-August. They assimilated approximately 5% as much inorganic carbon as the macrophytes from which they were taken. Epiphyte population densities followed the seasonal growth patterns of the macrophytes, with maximal leaf colonization remaining essentially constant relative to the leaf position on the plant. There was little change in density between sampling sites at any given time. Productivities of epiphytes from bottom leaves were 10-fold greater than those of epiphytes from top leaves. Addition of PO 4 -3 , NO 3 - , NH 3 , Si, and SO 4 -2 had no stimulatory effect on photosynthesis. Addition of HCO 3 - stimulated photosynthesis greater than 30%, suggesting that carbon may be a limiting nutrient for epiphytic algae in Lake George.

Quantifying the ecological impacts of alien aquatic macrophytes: A global meta‐analysis of effects on fish, macroinvertebrate and macrophyte assemblages

“…Alongside these physicochemical effects, macrophytes are key to an array of biotic interactions. They are colonised by diverse epiphytic assemblages which often make a contribution to productivity and nutrient exchange comparable to that of the macrophyte itself (Allen, 1971; Cattaneo & Kalff, 1980; Sheldon & Boylen, 1975). In addition, protection from predators and abundant food (e.g.…”

Quantitative and Qualitative Variability of Epiphytic Algae on Three Aquatic Plants in Euphrates River, Iraq

“…(1971) used the term "epiphytic periphyton" to describe both the attached algae and bacteria on aquatic plants (Scheldon and Boylen, 1975). Most species of these algae cover wide area and grow in rivers, lakes and reservoir attached on plants and released by current to water flow (Tharb, 1992).…”

“…The epiphytic algae act as primary producer in the food chain in water ecosystems (Dere et al, 2002), and as natural food to many zooplankton, grazer and fish (Loman, 2001). The density and diversity of these algae influenced by many environmental factors such as temperature, light, location, depth, and macrophyte host, and its abundance and growth phases of host aquatic plant (Scheldon and Boylen, 1975).…”

Taxonomy and Species Composition of Epiphytic Algae in Sta. Cruz River, Laguna (Philippines)

“…These plants have a significant function in water biocenoses, hydrology and sediment dynamics, biochemical cycles, structuring and altering the physico-chemical features (of an aquatic ecosystem) by photosynthesis, mineralization, and decomposition (Jeppesen et al, 2002;Joniak et al, 2007;Špoljar et al, 2012). Macrophytes have diverse species of microalgae attached to submerged plant parts which have been shown to be an important productive component of the aquatic ecosystem (Sheldon & Boylen, 1975). Algal epiphytes form a matrix system of microalgae and cyanobacteria attached to submerged aquatic macrophytes.…”