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algae biodiversity biological invasions birds California Cladophora competition disturbance ecology epiphytes erosion fish food web food webs freshwater mussels geomorphology indirect effects keystone species LiDAR mammals nutrients periphyton plants Rana boylii Riparian river food webs rivers species list stable isotope streams
2017 |
Vadeboncoeur, Yvonne; Power, Mary Attached Algae: The Cryptic Base of Inverted Trophic Pyramids in Freshwaters Journal Article Annual Review of Ecology, Evolution, and Systematics, 48 (1), pp. 255-279, 2017. Abstract | Links | BibTeX | Tags: Cladophora, cyanobacteria, diatoms, grazers, lakes, microphytobenthos, periphyton, primary consumer, primary producer, rivers @article{Vadeboncoeur2017, title = { Attached Algae: The Cryptic Base of Inverted Trophic Pyramids in Freshwaters}, author = {Yvonne Vadeboncoeur and Mary Power}, url = {http://angelo.berkeley.edu/wp-content/uploads/Annu.-Rev.-Ecol.-Evol.-Syst.-2017-Vadeboncoeur.pdf}, doi = {https://doi.org/10.1146/annurev-ecolsys-121415-032340}, year = {2017}, date = {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, grazers, lakes, microphytobenthos, periphyton, primary consumer, primary producer, rivers}, pubstate = {published}, tppubtype = {article} } 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. |
1994 |
Bergey, E A; Resh, V H Effects of burrowing by a stream caddisfly on case-associated algae Journal Article Journal of the North American Benthological Society, 13 (3), pp. 379-390, 1994. Abstract | Links | BibTeX | Tags: burrowing, caddisflies cases, diatoms, diel periodicity, Gumaga, rifigia, streams, Trichoptera @article{Bergey1994, title = {Effects of burrowing by a stream caddisfly on case-associated algae}, author = {E.A. Bergey and V.H. Resh}, url = {http://angelo.berkeley.edu/wp-content/uploads/Bergey_1994_JorBenthSoc.pdf}, doi = {10.2307/1467367}, year = {1994}, date = {1994-09-00}, journal = {Journal of the North American Benthological Society}, volume = {13}, number = {3}, pages = {379-390}, abstract = {Diel burrowing behavior of Gumaga nigricula (McL.) (Trichoptera:Sericostomatidae) was investigated in Big Sulphur Creek (Sonoma Co., California). Most of the population burrows during the day and surfaces at night, a behavior that facilitates feeding on periphyton while retaining many of the advantages of burrowing (e.g., protection from predators). Because of daytime burrowing, case algae (primarily diatoms) are potentially light-limited by overlying substrate and, indeed, chlorophyll a concentrations on stream-collected cases and diatom colonization on cleaned cases increased dramatically when daytime burrowing was prevented. Cases and case-associated algae are normally abraded during burrowing; therefore experimental abrasion had little effect. However, after cases were cultured to accrue algae, experimental abrasion drastically reduced the accrued algae. Blue-green algal filaments and diatoms were removed from exposed surfaces but were protected in crevices between sand grains. Comparison of cases of different caddisfly genera showed a trend between abrasion level and case-associated algae. Under low abrasion, grazer-resistant diatoms occurred on exposed surfaces and upright diatoms occurred in crevices (e.g., Glossosoma and Discosmoecus cases). As abrasion increased, diatoms were lost from exposed surfaces, although they remained in crevices (e.g., Gumaga cases); with continuous burrowing, cases were nearly devoid of algae (e.g., Agarodes cases)}, keywords = {burrowing, caddisflies cases, diatoms, diel periodicity, Gumaga, rifigia, streams, Trichoptera}, pubstate = {published}, tppubtype = {article} } Diel burrowing behavior of Gumaga nigricula (McL.) (Trichoptera:Sericostomatidae) was investigated in Big Sulphur Creek (Sonoma Co., California). Most of the population burrows during the day and surfaces at night, a behavior that facilitates feeding on periphyton while retaining many of the advantages of burrowing (e.g., protection from predators). Because of daytime burrowing, case algae (primarily diatoms) are potentially light-limited by overlying substrate and, indeed, chlorophyll a concentrations on stream-collected cases and diatom colonization on cleaned cases increased dramatically when daytime burrowing was prevented. Cases and case-associated algae are normally abraded during burrowing; therefore experimental abrasion had little effect. However, after cases were cultured to accrue algae, experimental abrasion drastically reduced the accrued algae. Blue-green algal filaments and diatoms were removed from exposed surfaces but were protected in crevices between sand grains. Comparison of cases of different caddisfly genera showed a trend between abrasion level and case-associated algae. Under low abrasion, grazer-resistant diatoms occurred on exposed surfaces and upright diatoms occurred in crevices (e.g., Glossosoma and Discosmoecus cases). As abrasion increased, diatoms were lost from exposed surfaces, although they remained in crevices (e.g., Gumaga cases); with continuous burrowing, cases were nearly devoid of algae (e.g., Agarodes cases) |
1987 |
Hill, W R; Knight, A W Experimental analysis of the grazing interaction between a mayfly and stream algae Journal Article Ecology, 68 (6), pp. 1955-1965, 1987. Abstract | Links | BibTeX | Tags: algae, Ameletus, assemblage structure, competition, diatoms, grazing, indirect effects, mayfly, periphyton, standing crop, streams @article{Hill1987, title = {Experimental analysis of the grazing interaction between a mayfly and stream algae}, author = {W.R. Hill and A.W. Knight}, url = {http://angelo.berkeley.edu/wp-content/uploads/Hill_1987_Eco.pdf}, doi = {10.2307/1939886}, year = {1987}, date = {1987-12-01}, journal = {Ecology}, volume = {68}, number = {6}, pages = {1955-1965}, abstract = {The interaction between the grazing mayfly Ameletus validus and periphyton in a small, northern California stream was examined by manipulating the density of the mayfly in flow—through plexiglass channels. Containing natural cobble substrate and located in situ, the channels established an initial gradient of A. validus at 0, 0.5, 1, and 4 times the average density of the mayfly in Barnwell Creek. After 23 d, A. validus significantly depressed periphyton standing crop: ash—free dry mass (AFDM) at the 0, 0.5, 1, and 4 N grazer densities was 5.067 ± 1.389 (se), 1.829 ± 0.173, 1.741 ± 0.325, and 1.009 ± 0.199 g/m2 (ANOVA: P < .01). The mayfly also influenced two structural attributes of the periphyton, increasing the amount of chlorophyll a per unit biomass and decreasing the relative contribution of the loose, upper layer to total periphyton biomass. Principal component analysis of algal relative abundances contrasted the effect of grazing on two groups of diatoms. A group of species found primarily in the loose layer of periphyton (Nitzschia spp., Surirella spiralis, Cymatopleura elliptica, and Navicula cryptocephala) was disproportionately reduced in abundance, while an adnate group (Gomphonema clevei, Achnanthes minutissima, Synedra ulna, Rhoicosphenia curvata, and an undescribed species of Epithemia) increased its relative abundance with increasing grazing pressure. The decline in relative abundance of the loose layer diatoms did not appear to result from selective consumption by A. validus, but may have been mediated by a reduction of inorganic sediment in the periphyton by A. validus. Inorganic sediment was highly correlated with the relative abundances of the loose layer group of diatoms, a group of species that are adapted for locomotion on sediment substrates. A. validus growth in the experimental channels was strongly density dependent. Growth in length over 23 d for the 0.5, 1, and 4 N treatments was 2.24 ± 0.17, 1.80 ± 0.23, and 1.15 ± 0.25 mm (ANOVA: P < .01). The significantly greater growth of A. validus at subnormal densities in the experimental channels suggested that the A. validus population in Barnwell Creek was food—limited.}, keywords = {algae, Ameletus, assemblage structure, competition, diatoms, grazing, indirect effects, mayfly, periphyton, standing crop, streams}, pubstate = {published}, tppubtype = {article} } The interaction between the grazing mayfly Ameletus validus and periphyton in a small, northern California stream was examined by manipulating the density of the mayfly in flow—through plexiglass channels. Containing natural cobble substrate and located in situ, the channels established an initial gradient of A. validus at 0, 0.5, 1, and 4 times the average density of the mayfly in Barnwell Creek. After 23 d, A. validus significantly depressed periphyton standing crop: ash—free dry mass (AFDM) at the 0, 0.5, 1, and 4 N grazer densities was 5.067 ± 1.389 (se), 1.829 ± 0.173, 1.741 ± 0.325, and 1.009 ± 0.199 g/m2 (ANOVA: P < .01). The mayfly also influenced two structural attributes of the periphyton, increasing the amount of chlorophyll a per unit biomass and decreasing the relative contribution of the loose, upper layer to total periphyton biomass. Principal component analysis of algal relative abundances contrasted the effect of grazing on two groups of diatoms. A group of species found primarily in the loose layer of periphyton (Nitzschia spp., Surirella spiralis, Cymatopleura elliptica, and Navicula cryptocephala) was disproportionately reduced in abundance, while an adnate group (Gomphonema clevei, Achnanthes minutissima, Synedra ulna, Rhoicosphenia curvata, and an undescribed species of Epithemia) increased its relative abundance with increasing grazing pressure. The decline in relative abundance of the loose layer diatoms did not appear to result from selective consumption by A. validus, but may have been mediated by a reduction of inorganic sediment in the periphyton by A. validus. Inorganic sediment was highly correlated with the relative abundances of the loose layer group of diatoms, a group of species that are adapted for locomotion on sediment substrates. A. validus growth in the experimental channels was strongly density dependent. Growth in length over 23 d for the 0.5, 1, and 4 N treatments was 2.24 ± 0.17, 1.80 ± 0.23, and 1.15 ± 0.25 mm (ANOVA: P < .01). The significantly greater growth of A. validus at subnormal densities in the experimental channels suggested that the A. validus population in Barnwell Creek was food—limited. |