Nutrient‐determined dominance in multispecies chemostat cultures of diatoms1

Mickelson, Michael J.; Maske, Helmut; Dugdale, Richard C.

doi:10.4319/lo.1979.24.2.0298

Cited by 44 publications

(21 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10 nM (Sunda & Hardison 2007), which appeared to be too low to allow growth of the larger species. Similar results have been observed in competition experiments between 2 small diatoms Skeletonema costatum and Chaetoceros septentrionalis and the much larger diatom Thalassiosira gravida in ammonium-limited chemostats (Mickelson et al 1979). As in our experiments, each of the smaller species outgrew the larger one under ammonium limitation; and once it became dominant, it drove ammonium concentrations to a sufficiently low level to stop the growth of the large diatom.…”

Section: Lack Of Fit To Standard Equationssupporting

confidence: 76%

Ammonium uptake and growth models in marine diatoms: Monod and Droop revisited

Sunda¹,

Shertzer²,

Hardison³

2009

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Mathematical models are a useful tool for predicting the responses of marine phytoplankton to changes in nutrient inputs and other environmental factors. Two modeling approachesMonod and Droop -have been traditionally used. These 2 model types were fitted to empirical data for specific growth rate, cellular N:C ratio, cellular ammonium uptake rate, and ammonium concentration measured in N-limited cyclostats at different dilution rates and in nutrient-saturated batch cultures. The modeled data were for a small, fast-growing coastal diatom Thalassiosira pseudonana (~4.5 μm diameter) and for a larger, slower growing diatom T. weissflogii (~11 μm diameter) cultured in seawater medium at 20°C and 14 h d -1 of light. The observed data did not conform well to the classic Monod equation, but could be fit to a modification of this equation in which the maximum growth rate was assigned a value higher than the observed maximum rate. Likewise, data for cellular N uptake rate versus ammonium concentration did not conform well to the standard saturation equation, but could be fit to a modification of the equation in which the maximum uptake rate was set above the empirically measured value and the x-intercept was shifted from the origin to a finite positive value. Both modified models accurately fit the observed steady-state relationships between ammonium concentrations and specific growth rates of the 2 species. However, the 2 models showed different transient dynamics in response to a change in the concentration of inflowing nutrients in time-course simulations. Such differences suggest that the choice between Droop and Monod approaches, when used as part of larger food web models, could lead to widely divergent predictions of algal blooms and other nonequilibrium dynamics of ecosystems.

show abstract

Section: Lack Of Fit To Standard Equationssupporting

confidence: 76%

Ammonium uptake and growth models in marine diatoms: Monod and Droop revisited

Sunda¹,

Shertzer²,

Hardison³

2009

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…While these changes can be detected in batch cultures when the shifts are large, it is difficult to distinguish more subtle community change in batch cultures because noncompetitive or nonviable cells remain in the vessels. Theoretically, a continuous system with a natural assemblage should result in a rapid and complete selection for one species whose growth rate is most favored by the conditions, competitively excluding all others from the system (Mickelson et al 1979;Rhee 1980;Turpin 1981). However, while steady state can be achieved using natural mixed communities, changes in species composition and diversity can be surprisingly slow (e.g., Dunstan and Menzel 1971;Thomas et al 1980), often requiring 25 to > 40 d for ~99% dominance of one species (competitive exclusion) to occur (Tilman 1977).…”

Section: Open Ocean Iron Experiment-surfacementioning

confidence: 99%

A sea‐going continuous culture system for investigating phytoplankton community response to macro‐ and micro‐nutrient manipulations

Pickell

Wells

Trick

et al. 2009

Limnology & Ocean Methods

View full text Add to dashboard Cite

Continuous cultures can provide refined insights on the response of phytoplankton communities to small changes in nutrient flux, however are logistically more challenging to perform at sea than batch cultures. Here we describe the design and successful testing of a new continuous culture system for shipboard experiments using natural phytoplankton communities. Using this system, we studied the effects of nitrate amendments in coastal waters of the Pacific Northwest, and low-level iron additions in High Nitrate, Low Chlorophyll (HNLC) waters of the subarctic Pacific. With nitrate amendments the coastal phytoplankton community showed proportional increases in chlorophyll biomass and appeared to achieve dynamic steady state as biomass, nutrient drawdown, and photo-physiology stabilized after 4 d. In contrast, biomass did not reach steady state with iron amendment in the 10-d HNLC experiment, however a major transition in dominant phytoplankton from small autotrophic flagellates to the toxigenic diatom Pseudo-nitzschia was observed. This new continuous culture design demonstrated high precision in flow rates, good mixing within culture vessels, and was simple to operate at sea. This system provides an effective platform for investigating small changes in macro-and micro-nutrient flux on the growth of individual phytoplankton species and, in turn, the trajectory of planktonic ecosystems.

show abstract

“…Classical resource partitioning has been demonstrated for nitrogen-limited marine systems by showing that the outcome of competition in continuous cultures depends on the nitrogen supply rate (Dunstan and Tenore 1974;Harrison and Davis 1979), and it continues to attract attention as a possible explanation for species distributions in nature (Mickelson et al 1979). In many freshwaters, where a variety of evidence points to frequent control of algal abundance by phosphorus supply (Vollenweider 1968;Schindler 1974;Healey and Hendzel 1980), it is especially interesting to examine the potential selective effects of an apparently ubiquitous limiting nutrient.…”

mentioning

confidence: 99%

Competition for phosphorus among co‐occurring freshwater phytoplankton1

Smith

Kalff

1983

Limnology & Oceanography

View full text Add to dashboard Cite

Competition at different levels of phosphorus availability was observed in continuous cultures of freshwater phytoplankton communities. Although dilution rates ranged 10‐fold in all, the outcome of competition was usually similar among cultures and resulted in dominance of the small diatom Synedra acus. Species growth rates decreased significantly with increasing cell, or colony, size among the 16 species examined. A variable internal stores model of algal growth, combined with functions relating its species‐specific parameters to cell size, correctly predicted the observed inverse correlation between cell size and competitive ability. The model’s predictions, and the empirical correlation between size and growth, were poor at low dilution rates (<0.2–0.3 d−1), probably due to cell death. The results indicated that variation of phosphorus supply is unlikely to be a major selective influence on the size or species composition of uniformly phosphorus‐limited communities.

show abstract

Nutrient‐determined dominance in multispecies chemostat cultures of diatoms1

Cited by 44 publications

References 29 publications

Ammonium uptake and growth models in marine diatoms: Monod and Droop revisited

Ammonium uptake and growth models in marine diatoms: Monod and Droop revisited

A sea‐going continuous culture system for investigating phytoplankton community response to macro‐ and micro‐nutrient manipulations

Competition for phosphorus among co‐occurring freshwater phytoplankton1

Contact Info

Product

Resources

About