Publications

@article{Vadeboncoeur2017,

title = {Attached Algae: The Cryptic Base of Inverted Trophic Pyramids in Freshwaters},

author = {Yvonne Vadeboncoeur and Mary Power},

url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Annu.-Rev.-Ecol.-Evol.-Syst.-2017-Vadeboncoeur.pdf},

doi = {https://doi.org/10.1146/annurev-ecolsys-121415-032340},

year  = {2017},

date = {2017-08-11},

urldate = {2017-08-11},

journal = {Annual Review of Ecology, Evolution, and Systematics},

volume = {48},

number = {1},

pages = {255-279},

abstract = {It seems improbable that a thin veneer of attached algae coating submerged surfaces in lakes and rivers could be the foundation of many freshwater food webs, but increasing evidence from chemical tracers supports this view. Attached algae grow on any submerged surface that receives enough light for photosynthesis, but animals often graze attached algae down to thin, barely perceptible biofilms. Algae in general are more nutritious and digestible than terrestrial plants or detritus, and attached algae are particularly harvestable, being concentrated on surfaces. Diatoms, a major component of attached algal assemblages, are especially nutritious and tolerant of heavy grazing. Algivores can track attached algal productivity over a range of spatial scales and consume a high proportion of new attached algal growth in high-light, low-nutrient ecosystems. The subsequent efficient conversion of the algae into consumer production in freshwater food webs can lead to low-producer, high-consumer biomass, patterns that Elton (1927) described as inverted trophic pyramids. Human perturbations of nutrient, sediment, and carbon loading into freshwaters and of thermal and hydrologic regimes can weaken consumer control of algae and promote nuisance attached algal blooms.},

keywords = {Cladophora, cyanobacteria, diatoms, ERCZO, grazers, lakes, microphytobenthos, periphyton, primary consumer, primary producer, rivers},

pubstate = {published},

tppubtype = {article}

}

@article{Gresens1995,

title = {Grazer diversity, competition and the response of the periphyton community},

author = {Susan E. Gresens},

url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Gresens_1995_Oikos.pdf},

issn = {0030-1299},

year  = {1995},

date = {1995-09-00},

journal = {Oikos},

volume = {73},

number = {3},

pages = {336-346},

abstract = {Enclosure of known densities of three species of benthic grazers demonstrated 1) that grazer species had qualitatively different effects on periphyton, and 2) that competitive interactions decreased growth and development of grazers at natural densities. Grazers (chironomid midge larvae, snails, chydorid Cladocera) did not significantly decrease biomass of periphyton attached to artificial substrates. Midge larvae and snails strongly increased the amount of deposited organic matter (feces) in enclosures. Interaction between midges and snails significantly decreased the amount of deposit present at high grazer densities. Snails increased biomass-specific chlorophyll content of attached algae. Grazers did not significantly alter the taxonomic composition of intact algae on substrates. However, midge density increased up to 70% the proportion of total algal biovolume on substrates which occured in fecal pellets. Total organic matter in enclosures was significantly increased at high midge density. Although periphyton food resources were not depleted, negative density dependent effects existed among grazers. High snail density decreased development of midge larvae by 50%, and reproduction of chydorids by 84%. Snails and midges also suffered from intraspecific competition. In the laboratory, activity of midge larvae decreased 29% in the presence of snails. Interference appears to be the predominant form of competition among these littoral grazers. Competitive interactions among benthic grazers may provide a negative feedback to perturbations at the top or bottom of littoral foodwebs},

keywords = {grazers, periphyton},

pubstate = {published},

tppubtype = {article}

}