Diatom Succession and Interaction in Littoral Periphyton and Plankton

Abstract

Periphyton and plankton samples were collected at four littoral stations in a relatively shallow, eutrophic lake (Elk Lake, B .C ., Canada) over a six month period from August 1967 to January 1968 . The most abundant planktonic diatoms demonstrated a pattern of seasonal succession typical of temperate lakes, and all were present in the periphyton . This pattern was identical at all stations : Fragilaria crotonensis was dominant from August to October, Asterionella formosa in November and December, and Melosira italica (plus M. varians) in January . F. virescens, although never dominant, peaked in October . Periphyton communities were dominated by Achnanthes minutissima, Cocconeis placentula, F. crotonensis and F. virescens . Considerable station variation in successional patterns occurred over different exposure periods ; station differences were least in those samples immersed for monthly intervals, and greatest in those immersed for a cumulative four-month period . Interaction between the phytoplankton and periphyton was illustrated by the occurrence of species common to both habitats . A decrease in cell numbers and percent abundance of these species in planktonic populations coincided with their increase in the periphyton, a relationship which appeared dependent on the breakdown of thermal stratification in November . For example, following turnover, F. crotonensis and A . formosa settled out of the plankton and correspondingly increased in percent abundance in the periphyton . This interdependence was less evident in the four-month samples, where A . minutissima and C. placentula dominated throughout the entire period and appeared to out-compete the more typical planktonic components for diminishing substrate area . Species interaction or competition was accentuated as exposure duration and periphyton total cell standing crops increased and species diversity decreased, and appeared to account in part, for station differences in successional patterns .

Competition between three estuarine benthic diatom species in mixed cultures

“…The existence of density-dependent factors in nature is indicated by the negative correlations between the species diversity and the density of benthic diatom populations (Brown and Austin, 1973;Colijn and Dijkema, 1981;Admiraal et al, 1984). Another indication is provided by the similarity between the population density in our step-wise diluted cultures and that in well developed natural communities.…”

Changes in periphytic algal community structure as a consequence of short herbicide exposures

“…Brown & Austin (1973) found that the density of C. placentula on glass slides was correlated with the density of Achnanthes minutissima such that increases in the proportion of one corresponded to decreases in the other. Patrick (1978) described a similar relationship between C. placentula and A. lanceolata while TUchmann & Blinn (1979) have reported a relationship between the relative proportions of C. placentula and Amphora coffeiformis (Ag.…”

“…A survey of the literature has indicated a preference for slow moving water in lotic habitats (Jones, 1978), horizontal positioning (Godward, 1934), moderate specific conductance and alkalinity (Patrick & Reimer, 1966;Higashi et al, 1981;Tuchmann & Blinn, 1979), moderate water temperature (Hickman & Klarer, 1974;Tuchmann & Blinn, 1979;Hickman, 1982), high nitrate concentration (Patrick, 1978;Fairchild et al, 1985), high phosphate concentration (Fairchild et aL, 1985), high potassium, calcium and zinc concentrations (Podzorski, 1984), and low light intensity (Hickman & Klarer, 1974;Hickman, 1982;Jenkerson & Hickman, 1983). Other factors which may be related to high Cocconeis density include reduced susceptibility to grazing pressure (Patrick, 1970;Kesler, 1981), extended colonization period (Kesler, 1981), increased substratum age (Siver, 1978;Rogers & Breen, 1981) and mid-late summer season (Brown & Austin, 1973;Kesler, 1981;Hickman, 1982). Some of these conclusions have undoubtedly arisen from subjective interpretations of assumed cause and effect relationships between observed periodicity and environmental factors.…”

Effects of grazing and light on the growth ofNostoc pruniforme(Cyanobacteria)

“…Brown & Austin (1973) found Cocconeis placentula Ehr. to be dominant on glass slides placed in the littoral region of a lake.…”