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2006 |
Lowe, W H; Likens, Gene E; Power, Mary E Linking Scales in Stream Ecology Journal Article BioScience, 56 (7), pp. 591-597, 2006. Abstract | Links | BibTeX | Tags: 16S rRNA microarrays, networks, resiliency, rivers, streams @article{111b, title = {Linking Scales in Stream Ecology}, author = {W.H. Lowe and Gene E. Likens and Mary E. Power}, url = {https://angelo.berkeley.edu/wp-content/uploads/Lowe_2006_BioScience.pdf}, doi = {10.1641/0006-3568(2006)56[591:LSISE]2.0.CO;2}, year = {2006}, date = {2006-07-01}, journal = {BioScience}, volume = {56}, number = {7}, pages = {591-597}, abstract = {The hierarchical structure of natural systems can be useful in designing ecological studies that are informative at multiple spatial scales. Although stream systems have long been recognized as having a hierarchical spatial structure, there is a need for more empirical research that exploits this structure to generate an understanding of population biology, community ecology, and species–ecosystem linkages across spatial scales. We review studies that link pattern and process across multiple scales of stream-habitat organization, highlighting the insight derived from this multiscale approach and the role that mechanistic hypotheses play in its successful application. We also describe a frontier in stream research that relies on this multiscale approach: assessing the consequences and mechanisms of ecological processes occurring at the network scale. Broader use of this approach will advance many goals in applied stream ecology, including the design of reserves to protect stream biodiversity and the conservation of freshwater resources and services.}, keywords = {16S rRNA microarrays, networks, resiliency, rivers, streams}, pubstate = {published}, tppubtype = {article} } The hierarchical structure of natural systems can be useful in designing ecological studies that are informative at multiple spatial scales. Although stream systems have long been recognized as having a hierarchical spatial structure, there is a need for more empirical research that exploits this structure to generate an understanding of population biology, community ecology, and species–ecosystem linkages across spatial scales. We review studies that link pattern and process across multiple scales of stream-habitat organization, highlighting the insight derived from this multiscale approach and the role that mechanistic hypotheses play in its successful application. We also describe a frontier in stream research that relies on this multiscale approach: assessing the consequences and mechanisms of ecological processes occurring at the network scale. Broader use of this approach will advance many goals in applied stream ecology, including the design of reserves to protect stream biodiversity and the conservation of freshwater resources and services. |
2003 |
Finlay, Jacques C Controls of streamwater dissolved inorganic carbon dynamics in a forested watershed Journal Article Biogeochemistry, 62 (3), pp. 231-252, 2003, ISSN: 1573-515X. Abstract | Links | BibTeX | Tags: CO2, Dissolved inorganic carbon, Metabolism, Stable carbon isotopes, streams, Weathering @article{Finlay2003, title = {Controls of streamwater dissolved inorganic carbon dynamics in a forested watershed}, author = {Jacques C. Finlay}, url = {https://angelo.berkeley.edu/wp-content/uploads/Controls-of-streamwater-dissolved-inorganic-carbon-dynamics-in-a-forested-watershed_Finlay_2002.pdf}, doi = {10.1023/A:1021183023963}, issn = {1573-515X}, year = {2003}, date = {2003-03-01}, journal = {Biogeochemistry}, volume = {62}, number = {3}, pages = {231-252}, abstract = {I investigated controls of stream dissolved inorganic carbon (DIC) sources andcycling along a stream size and productivity gradient in a temperate forestedwatershed in northern California. Dissolved CO2 (CO2(aq))dynamics in heavily shaded streams contrasted strongly with those of larger,open canopied sites. In streams with canopy cover > 97%, CO2 (aq)was highest during baseflow periods (up to 540 μM) and wasnegatively related to discharge. Effects of algal photosynthesis on CO2(aq) were minimal and stream CO2 (aq) was primarily controlledby groundwater CO2 (aq) inputs and degassing losses to theatmosphere. In contrast to the small streams, CO2 (aq) in larger,open-canopied streams was often below atmospheric levels at midday duringbaseflow and was positively related to discharge. Here, stream CO2(aq) was strongly influenced by the balance between autotrophic andheterotrophic processes. Dynamics of HCO3 − werelesscomplex. HCO3 − and Ca2+ were positivelycorrelated, negatively related to discharge, and showed no pattern with streamsize. Stable carbon isotope ratios of DIC (i.e. δ13C DIC)increased with stream size and discharge, indicating contrasting sources of DICto streams and rivers. During summer baseflows, δ13C DIC were13C-depleted in the smallest streams (minimum of−17.7‰) due to the influence of CO2 (aq) derived frommicrobialrespiration and HCO3 − derived from carbonateweathering. δ13C DIC were higher (up to −6.6‰)inthe larger streams and rivers due to invasion of atmospheric CO2enhanced by algal CO2 (aq) uptake. While small streams wereinfluenced by groundwater inputs, patterns in CO2 (aq) and evidencefrom stable isotopes demonstrate the strong influence of stream metabolism andCO2 exchange with the atmosphere on stream and river carbon cycles.}, keywords = {CO2, Dissolved inorganic carbon, Metabolism, Stable carbon isotopes, streams, Weathering}, pubstate = {published}, tppubtype = {article} } I investigated controls of stream dissolved inorganic carbon (DIC) sources andcycling along a stream size and productivity gradient in a temperate forestedwatershed in northern California. Dissolved CO2 (CO2(aq))dynamics in heavily shaded streams contrasted strongly with those of larger,open canopied sites. In streams with canopy cover > 97%, CO2 (aq)was highest during baseflow periods (up to 540 μM) and wasnegatively related to discharge. Effects of algal photosynthesis on CO2(aq) were minimal and stream CO2 (aq) was primarily controlledby groundwater CO2 (aq) inputs and degassing losses to theatmosphere. In contrast to the small streams, CO2 (aq) in larger,open-canopied streams was often below atmospheric levels at midday duringbaseflow and was positively related to discharge. Here, stream CO2(aq) was strongly influenced by the balance between autotrophic andheterotrophic processes. Dynamics of HCO3 − werelesscomplex. HCO3 − and Ca2+ were positivelycorrelated, negatively related to discharge, and showed no pattern with streamsize. Stable carbon isotope ratios of DIC (i.e. δ13C DIC)increased with stream size and discharge, indicating contrasting sources of DICto streams and rivers. During summer baseflows, δ13C DIC were13C-depleted in the smallest streams (minimum of−17.7‰) due to the influence of CO2 (aq) derived frommicrobialrespiration and HCO3 − derived from carbonateweathering. δ13C DIC were higher (up to −6.6‰)inthe larger streams and rivers due to invasion of atmospheric CO2enhanced by algal CO2 (aq) uptake. While small streams wereinfluenced by groundwater inputs, patterns in CO2 (aq) and evidencefrom stable isotopes demonstrate the strong influence of stream metabolism andCO2 exchange with the atmosphere on stream and river carbon cycles. |
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 = {https://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) |
1988 |
Power, Mary E; Stout, Jean R; Cushing, Colbert E; Harper, Peter P; Hauer, Richard F; Matthews, William J; Moyle, Peter B; Statzner, Bernhard; Badgen, Irene Wais De R Biotic and abiotic controls in river and stream communities Journal Article Journal of the North American Benthological Society, 7 (4), pp. 456-479, 1988. Abstract | Links | BibTeX | Tags: algae, COMMUNITIES, discharge, disturbance., fish, life histories, rivers, streams, zoobenthos @article{Power1988, title = {Biotic and abiotic controls in river and stream communities}, author = {Mary E. Power and R. Jean Stout and Colbert E. Cushing and Peter P. Harper and F. Richard Hauer and William J. Matthews and Peter B. Moyle and Bernhard Statzner and Irene R. Wais De Badgen}, url = {https://angelo.berkeley.edu/wp-content/uploads/Power_1988_BenthoSoc.pdf}, doi = {10.2307/1467301}, year = {1988}, date = {1988-12-00}, journal = {Journal of the North American Benthological Society}, volume = {7}, number = {4}, pages = {456-479}, abstract = {Lotic ecologists share a major goal of explaining the distribution and abundance of biota in the world's rivers and streams, and of predicting how this biota will respond to change in fluvial ecosystems. We discuss five areas of research that would contribute to our pursuit of this goal. For mechanistic understanding of lotic community dynamics, we need more information on: 1. Physical conditions impinging on lotic biota, measured on temporal and spatial scales relevant to the organisms. 2. Responses of lotic biota to discharge fluctuations, including the processes that mediate community recovery following resets caused by spates or droughts. 3. Movements of lotic organisms that mediate gene flow, resource tracking, and multilevel species interactions. 4. Life history patterns, with special emphasis on ontogenetic bottlenecks that determine the vulnerability of populations confronting environmental perturbation. 5. Consequences of species interactions for community- and ecosystem-level processes in rivers and streams. Without attempting to be comprehensive in our review, we discuss limits and limitations of our knowledge in these areas. We also suggest types of data and technological development that would advance our understanding. While we appreciate the value and need for empirical and comparative information, we advocate search for key mechanisms underlying community interactions as the crucial step toward developing general predictions of responses to environmental change. These mechanisms are likely to be complex, and elucidation of interacting bilateral, or multilateral, biotic and abiotic controls will progress only with the continuing synthesis of community- and ecosystem-level approaches in lotic ecology.}, keywords = {algae, COMMUNITIES, discharge, disturbance., fish, life histories, rivers, streams, zoobenthos}, pubstate = {published}, tppubtype = {article} } Lotic ecologists share a major goal of explaining the distribution and abundance of biota in the world's rivers and streams, and of predicting how this biota will respond to change in fluvial ecosystems. We discuss five areas of research that would contribute to our pursuit of this goal. For mechanistic understanding of lotic community dynamics, we need more information on: 1. Physical conditions impinging on lotic biota, measured on temporal and spatial scales relevant to the organisms. 2. Responses of lotic biota to discharge fluctuations, including the processes that mediate community recovery following resets caused by spates or droughts. 3. Movements of lotic organisms that mediate gene flow, resource tracking, and multilevel species interactions. 4. Life history patterns, with special emphasis on ontogenetic bottlenecks that determine the vulnerability of populations confronting environmental perturbation. 5. Consequences of species interactions for community- and ecosystem-level processes in rivers and streams. Without attempting to be comprehensive in our review, we discuss limits and limitations of our knowledge in these areas. We also suggest types of data and technological development that would advance our understanding. While we appreciate the value and need for empirical and comparative information, we advocate search for key mechanisms underlying community interactions as the crucial step toward developing general predictions of responses to environmental change. These mechanisms are likely to be complex, and elucidation of interacting bilateral, or multilateral, biotic and abiotic controls will progress only with the continuing synthesis of community- and ecosystem-level approaches in lotic ecology. |
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 = {https://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. |