Effects of Grazers on Freshwater Benthic Algae

Steinman, Alan D.

doi:10.1016/b978-012668450-6/50041-2

Cited by 267 publications

(347 citation statements)

References 139 publications

Supporting

Mentioning

324

Contrasting

Unclassified

Order By: Relevance

“…These findings are in agreement with previous studies on benthic diatoms from marine (e.g., Hillebrand et al 2000), and freshwater (Steinman 1996;Hill et al 1997), habitats. In our study, the absence of grazers generally favoured the abundance of the diatom genus Cocconeis.…”

Section: Grazing Effectssupporting

confidence: 83%

Grazing and UV radiation effects on an Antarctic intertidal microalgal assemblage: a long-term field study

Zacher

Hanelt²,

Wiencke

et al. 2007

Polar Biol

View full text Add to dashboard Cite

A 15 week field experiment (austral summer Nov-Mar) was carried out in an intertidal hard bottom platform in Antarctica (King George Island). To test whether grazing and ultraviolet radiation (UVR) influenced the succession of a benthic microalgal assemblage, a twofactorial design was used (1) ambient radiation, >280 nm; (2) ambient minus UV-B, >320 nm; (3) ambient minus UVR, >400 nm versus grazer-no grazer). On four sampling occasions microalgae were identified, counted and carbon contents were calculated. The assemblage was dominated by the diatom genera Navicula and Cocconeis. Biomass was generally low in all treatments but was significantly reduced by grazing throughout the experiment. No significant UV effects were found. Grazer absence particularly favoured diatoms of the genus Cocconeis. We conclude that the Antarctic microalgal assemblage was unaffected by present day UVR whereas grazers acted as important drivers on the intertidal microalgal community structure.

show abstract

Section: Grazing Effectssupporting

confidence: 83%

Grazing and UV radiation effects on an Antarctic intertidal microalgal assemblage: a long-term field study

Zacher

Hanelt²,

Wiencke

et al. 2007

Polar Biol

View full text Add to dashboard Cite

show abstract

“…Despite the highest algal biomass in the forest site, biomass of scrapers was higher in the open reach. As periphyton was dominated by diatoms and H. foetidus in both sites we cannot attribute this mismatch to differences in periphyton composition, which may lead to differences in biofilm palatability (Steinman, 1996) and quality (Lamberti, 1996). Light energy usually leads to higher grazer biomass instead of an increase in periphyton biomass, which can even decrease slightly (McIntire et al, 1996;Wellnitz et al, 1996;Hillebrand, 2005).…”

Section: Discussionmentioning

confidence: 97%

Primary consumers and resources: Annual variation in two contrasting reaches of a Patagonian mountain stream

Villanueva

Buria²,

Albariño

2010

Ann. Limnol. - Int. J. Lim.

View full text Add to dashboard Cite

-Resource availability influences the flow of energy through food webs, thus affecting biomass and trophic structure of consumer communities. To assess the effect of availability of allochthonous (leaf litter) and autochthonous (periphyton) resources on the trophic structure of macroinvertebrates, we sampled monthly for a year two sites (upstream forested, downstream open canopy) of Challhuaco, a low order mountain stream in the Patagonian Andes. Leaf litter and periphyton dynamics showed the expected pattern, peaking in autumn and spring, respectively. Temporal variations of shredders and scrapers were synchronized, with the logic delay, with resource abundance. Although leaf litter mass was similar at both stream reaches, shredders were more abundant at the forest site. Periphyton biomass was higher at the forest, while scrapers were more abundant at the open site. The patterns of resource and consumer abundance, and community functional structure were mostly explained by the interaction of abiotic factors and trophic relationships.

show abstract

“…For example, strong asymmetric grazing control in the phytoplankton eliminates sensitive species, allowing the exclusive proliferation of a few species with anti-grazer defences, which further increase their biomass through positive feedbacks (Irigoien et al 2005). Grazer selectivity is much less pronounced in the benthos, where entire guilds, comprising understorey and motile species, can successfully avoid herbivory and even increase in abundance and primary production in the presence of grazers (Steinman 1996). Therefore, the discovery of maximum biomass at lower SR in the phytoplankton than in the benthos is not surprising.…”

Section: Discussionmentioning

confidence: 99%

Are algal communities driven toward maximum biomass?

Passy

Legendre

2006

Proc. R. Soc. B.

View full text Add to dashboard Cite

In this continental-scale study, we show that in major benthic and planktonic stream habitats, algal biovolume-a proxy measure of biomass-is a unimodal function of species richness (SR). The biovolume peak is observed at intermediate to high SR in the benthos but at low richness in the phytoplankton. The unimodal nature of the biomass-diversity relationship implies that a decline in algal biomass with potential harmful effects on all higher trophic levels, from invertebrates to fish, can result from either excessive species gain or species loss, both being common consequences of human-induced habitat alterations. SR frequency distributions indicate that the most frequent richness is habitat-specific and significantly higher in the benthos than in the plankton. In all studied stream environments, the most frequent SR is lower than the SR that yields the highest biovolume, probably as a result of anthropogenic influences, but always within one standard deviation from it, i.e. they are statistically indistinguishable. This suggests that algal communities may be driven toward maximum biomass.

show abstract

Effects of Grazers on Freshwater Benthic Algae

Cited by 267 publications

References 139 publications

Grazing and UV radiation effects on an Antarctic intertidal microalgal assemblage: a long-term field study

Grazing and UV radiation effects on an Antarctic intertidal microalgal assemblage: a long-term field study

Primary consumers and resources: Annual variation in two contrasting reaches of a Patagonian mountain stream

Are algal communities driven toward maximum biomass?

Contact Info

Product

Resources

About