bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction between chemical and tactile cues in mayfly detection of stoneflies
Authors: ODE PETER R. , WISSINGER SCOTT A. 
Published: May 2006

SUMMARY

Behavioural experiments were performed in artificial stream channels to determine if nymphs of the mayfly Paraleptophlebia adoptiva (Ephemeroptera: Leptophlebiidae) respond to (i) chemical cues from stonefly nymphs, (ii) chemical cues from disturbed conspecific mayflies, and (iii) body fluids of injured conspecifics, and (iv) whether responses to these chemical cues are different when combined with contact by foraging Acroneuria carolinensis stonefly nymphs (Plecoptera: Perlidae).
Although none of the chemical cues elicited changes in mayfly behaviour in the absence of predator contact, stonefly chemical cues significantly enhanced the avoidance response of mayflies to stonefly contact. Mayfly nymphs swam more frequently and crawled further in response to predator encounters when chemical cues were present than when chemical cues were absent. Thus, direct stonefly precontact chemical cues appear to sensitize P. adoptiva to the potential for an encounter with A. carolinensis, enabling stronger escape or avoidance responses upon contact.
Mayfly chemical cues that provide indirect information about the proximity of a predator (disturbed or injured conspecifics) did not stimulate increased mayfly response to stonefly contact. Indirect cues may provide less reliable information about the proximity of a stonefly than chemicals emitted directly from an adjacent predator. Mayflies might use chemical cues only in the presence of predator contact because of the high cost of premature escape in a running water system.
Production of new organic carbon and its distribution between autotrophic picoplankton, bacteria, extracellular organic carbon and phytoplankton in an upland lake
Authors: HAPPEY‐WOOD CHRISTINE M. , LUND ANDERS H. 
Published: May 2006

SUMMARY

Picoplankton community production (0.2–2μm) was investigated over 3 months, June‐September 1991, in Llyn Padarn, a mesotrophic upland lake in north Wales.
The picoplankton was differentiated into autotrophic algae (<1–3μm) and heterotrophic bacteria (<0.2–1 μm) using differential filtration through a 1 μm pore size Nuclepore filter.
Efficient separation of these distinct metabolic constituents of picoplankton was obtained. A good correlation (r= 0.81, P < 0.001) was found between physical separation of bacterial and picoalgal cells from fluorescence microscopy and the distribution of heterotrophic metabolic activity between different cell size fractions measured by uptake of 14C‐glucose.
Picoplankton community production was differentiated into the ‘absolute’ autotrophic production by picoalgae, corrected for overestimation due to retention of bacteria with the picoalgae, and the heterotrophic component, bacterial uptake of ‘extracellular organic carbon’ (EOC), derived from the entire phytoplankton community.
The heterotrophic contribution to picoplankton community production ranged from 88 to 1%, mean value 55% of total. Autotrophic picoplankton production was dominant in June and July, but in August and September heterotrophic uptake of EOC was the major input to picoplankton community production.
During the 3 months, the mean contributions to plankton production were autotrophic picoplankton 10.3%, heterotrophic bacterial uptake of EOC 9.7%, EOC in lake water 11.6% and phytoplankton (>3μm) 68.3%.
Bacteria accounted for about half the picopfankton community production via uptake of EOC. Thus although autotrophic picoplankton were ubiquitous, it is likely that their contribution via primary production to the carbon balance of planktonic environments has been overestimated in previous studies.
Patterns of life history among cyclopoid copepods of central Europe
Authors: MAIER GERHARD 
Published: May 2006

SUMMARY

Life history characters (body size of adults, egg diameter, egg sac length and breadth) of nineteen species of central European cyclopoid copepods were measured and sexual size dimorphism (adult female length x adult male length−1), relative egg size (egg weight X body weight−1), weight of adult females and of eggs, egg sac shape (egg sac length x egg sac breadth−1), and reproductive effort (clutch weight produced per female weight per day) were calculated to detect trends in life history strategies.
Typical planktonic species exhibited the lowest reproductive effort. Among planktonic species, the value for egg sac shape increased with clutch size.
Large species and small species exhibited different trends in life history characters. Large species had larger clutches, larger eggs, and a greater sex size dimorphism than small species. However, small species had a greater relative egg size.
Large species live in cold water and reproduce during the spring bloom of phytoplankton where the production of large clutches with relatively small eggs is advantageous. Reserves are unnecessary for juveniles because food is abundant. Small species generally are most abundant during the warm season, when conditions are less predictable, and relatively large eggs, possibly provided with reserves, are advantageous.
Trophic interactions and benthic animal community structure in the Colorado River, Arizona, U.S.A.
Authors: SHANNON JOSEPH P. , BLINN DEAN W. , STEVENS LAWRENCE E. 
Published: May 2006

SUMMARY1. Cladophora glomerata is the dominant filamentous green alga in the tailwaters of the Colorado River, U.S.A., below Glen Canyon Dam, but becomes co‐dominant with filamentous cyanobacteria, Oscillatoria spp., below the confluence of the Paria River (26km below the dam) where suspended sediments are elevated.2. Benthic algal assemblages played an important role in the distribution of the amphipod, Gammarus lacustris, in the dam‐controlled Colorado River through Grand Canyon National Park, Arizona. Cladophara and G. lacustris showed a weak positive relationship at ten cobble‐riffle habitats in the Colorado River from Lees Ferry (25km below the dam) to Diamond Creek (362km downstream), while no relationship was found between Oscillatoria and G. lacustris.3. The relationship between algal substrata and G. lacustris was tested by a series of in situ habitat choice experiments. G. lacustris showed a significant preference for Cladophora (with epiphytes) over Oscillatoria spp., detritus and gravel in treatment pans at Lees Ferry.4. Epiphytic diatoms (i.e. food) were the overriding determinant of subtratum choice by G. lacustris in laboratory experiments. Gammarus chose the Cladophora/epiphytic diatom community over sonicated Cladophora with few diatoms. The amphipods also chose string soaked in diatom extract over string without diatom extract.5. Importance of mutualistic interactions in aquatic benthic community structure is discussed.
Effects of single and repeated experimental acid pulses on invertebrates in a high altitude Sierra Nevada stream
Authors: KRATZ KIM W. , COOPER SCOTT D. , MELACK JOHN M. 
Published: May 2006

SUMMARY1. We examined responses of aquatic macroinvertebrates to pulsed acidification experiments in twelve streamside channels located in the Sierra Nevada, California. Experiment 1 consisted of a single 8 h acid addition, and Experiment 2 consisted of two 8 h acid additions administered 2 weeks apart. Replicated treatments (four reps/ treatment) consisted of a control (pH 6.5–6.7) and pH levels of 5.1–5.2 and 4.4–4.6. Invertebrate drift was monitored continuously and benthic densities were determined before and after acid addition.2. Drift responses to pH reduction were: (i) increased drift during acidification in pH 5.2 and pH 4.6 treatment channels, often with depressed post‐acidification drift in treatment channels relative to controls (exhibited by Baetis only). Depressed post‐acidification drift in treatment channels appeared to be due to low benthic densities because a positive relationship between benthic and drift densities was noted for most common taxa; (ii) increased drift rates during acidification only at pH 4.6 (Epeorus, Drunella, Paraleptophlebia, Zapada, and Simulium); (iii) decreased drift at pH 5.2 and/or pH 4.6 relative to control channels (Rhyacaphila and chironomid larvae); (iv) no significant response to acidification (Ameletus, Amiocentrus, Dixa and Hydroporus).3. A high proportion (45–100%) of acid‐induced drift in Baetis, Epeorus, and chironomid larvae could be attributed to dead, drifting individuals.4. Except for chironomids, most common invertebrates (i.e. Baetis and Paraleptophlebia) showed reduced benthic densities in treatment relative to control channels after acidification.5. For sensitive taxa, drift was enhanced and benthic densities reduced by single (Experiment 1) and initial [Experiment 2(a)] acid pulses. Drift responses to a second acid pulse [Experiment 2(b)] were not as pronounced as those to the single or initial acid pulses [Experiments 1 and 2(a)], and the second acid pulse had no additional effect on benthic density.
Ecology of alpine, glacial, high latitude and mountain streams: introduction and synthesis
Authors: WINTERBOURN MICHAEL J. 
Published: May 2006

SUMMARY1. This paper provides the introduction to a special issue of Freshwater Biology devoted to papers dealing with aspects of the physical environment and ecology of alpine, glacial, high latitude and mountain streams.2. Eleven of the sixteen papers were included in a symposium that formed part of the scientific programme of the North American Benthological Society Annual Meeting in Calgary, Alberta, Canada, in May 1993.3. The contributions are a combination of reviews, overviews and primary research articles that deal with streams and ecological issues in Alaska, Nepal, New Zealand, Switzerland and southern Africa. Important issues considered include environmental consequences of river ice; altitudinal and temporal distributions of stream biota, especially macroinvertebrates; litter processing; and bryophyte production.
Mountain streams in Westland, New Zealand: benthic ecology and management issues
Authors: WINTERBOURN MICHAEL J. , RYAN PADDY A. 
Published: May 2006

SUMMARY1. The West Coast of the South Island, New Zealand (Westland) is a region of mountains, forests, high rainfall, and a history of exploitation. The Southern Alps rise to over 3000m in the east of the region, and a narrow coastal plain supports some agriculture and the main centres of population.2. Stream waters in the Southern Alps are characterized by low concentrations of major ions, and most can be described as calcium—sodium—bicarbonate waters. Brown waters with low pH and high concentrations of dissolved organic carbon are common at low and intermediate altitudes.3. Many mountain streams and rivers provide physically harsh environments for aquatic biota with their rapidly changing flows and frequent spates. Hydrological factors and low nutrient concentrations limit periphyton standing crops, and biomass of coarse detritus is often low. Invertebrate populations are usually dominated by insect larvae that feed primarily on FROM and stone surface biofilms.4. Features of the macroinvertebrate stream fauna on the West Coast are the wide range of physicochemical conditions tolerated by many common species, and the numerical dominance of the mayfly Deleatidium (Leptophlebiidae) in many streams. The Plecoptera also exhibit high diversity relative to other parts of the country, and an unusual trend towards terrestrialism is shown by larvae of Gripopterygidae.5. The West Coast has a long history of coal and gold mining, forestry and farming, activities that have had negative impacts on stream communities and water quality. We discuss some ecological and management issues associated with present day mining practices, and a proposal to take large volumes of alpine stream water for export.
Influence of water abstraction on the macroinvertebrate community gradient within a glacial stream system: La Borgne d'Arolla, Valais, Switzerland
Authors: PETTS GEOFFREY E. , BICKERTON MELANIE A. 
Published: May 2006

SUMMARY1. Water abstraction from glacial rivers is an important characteristic of hydroelectric power schemes in Alpine regions. Streams in the Valais region of Switzerland have been particularly affected.2. Invertebrate distributions are described in La Borgne d'Arolla, a glacial stream with icemelt‐, snowmelt‐ and groundwater‐dominated tributaries. The icemelt‐dominated streams have been affected by abstractions for more than 30 years.3. The glacial streams contain only Chironomidae(Diamesa), and are devoid of fauna for between 200 and 500 m below the glacier snouts.4. Immediately below the water intakes the streams are intermittent, flowing only during system purges and high floods, and are devoid of fauna for short distances (<1.5km).5. Further downstream, abstraction of glacial meltwater increases the importance of snowmelt and groundwater, increasing water temperatures, improving water clarity and increasing the length of krenal/rhithral streams at the expense of kryal streams.6. A community including Chironomidae, Simuliidae, Baetidae, Nemouridae, Limnephilidae and Chloroperlidae occurs as soon as a permanent flow is maintained by tributary runoff, and the channel becomes stable.7. A wide range of taxa inhabit snowmelt‐ and groundwater‐dominated tributary streams with stable channels, often at much higher altitudes than the main river. The tributaries provide sources for rapid colonization of the main channel following ice retreat or physical disturbance.8. Purges and high floods are important disturbances within the main channel. Recovery may be rapid because of drift from tributaries, but sites influenced by frequent disturbances have reduced faunas in comparison to stable channel sites.9. This study supports the model proposed by Milner & Petts (1994) and shows that deterministic responses of macroinvertebrate communities may be observed to changes of temperature, turbidity, flow regime and channel stability.
Life histories of burrowing mayflies (Hexagenia limbata and H. rigida, Ephemeroptera: Ephemeridae) in a northern Canadian reservoir
Authors: GIBERSON DONNA J. , ROSENBERG DAVID M. 
Published: May 2006

SUMMARY1. The life histories and population dynamics of the burrowing mayflies Hexagenia Umbata and H. rigida were examined from 1986 to 1988 in four regions of an impounded lake in northern Manitoba, Canada.2. Bottom temperatures reached 15–20°C, but ice‐free periods of 4–6 months resulted in annual degree day (dd > 10°C) accumulations of only 210–650 in various regions and years.3. The life cycles (egg to adult) of both Hexagenia species required 3yr in the three warmest regions studied and 4yr in the coolest area; total dd accumulations to complete the life cycle ranged from 1222 to 1468 dd > 10°C.4. Fecundity (no. of eggs/) was strongly correlated to body size of subimagos, and subimago size was strongly correlated to length of nymphal exuviae, so field collection of nymphal exuviae could be used to determine both the size and fecundity of the emerging females.5. Degree day accumulation in the final year before emergence was a better predictor of emergence timing than overall dd accumulations for the life cycle.
Exploitation of sediment bacterial carbon by juveniles of the amphipod Monoporeia affinis
Authors: GOEDKOOP WILLEM , JOHNSON RICHARD K. 
Published: May 2006

SUMMARY1. Carbon budget parameters were measured for young‐of‐the‐year Monoporeia affinis in a combined field and laboratory (microcosm) study, designed to quantify the role of sediment bacteria as a carbon source for juvenile amphipods. Special emphasis was placed on the stimulative effects of amphipod activity (foraging, feeding, bioturbation) on sediment bacterial production and abundance by including the carbon thus generated in carbon budget calculations.2. Amphipod production was clearly higher at lower densities, suggesting strong intraspecific interactions. Negative production was recorded at amphipod densities of 10000 and 20000 ind. m−2. Negative production was not accompanied by a decrease in amphipod total lipid content, however, probably due to the lack of easily mobilized lipids in juvenile amphipods. Amphipod respiration rate was 0.45 μg O2 ind.−1 h−1, or O.15 μg C ind.−1 h−1. Sediment bacterial carbon content averaged 1.31 and 0.90 mg g−1 DW under field and laboratory conditions, respectively.3. Bacterial carbon was not quantitatively important for Monoporeia. Due to higher bacterial abundance and production in natural, stratified sediment, assimilation of bacterial carbon was highest for the field population, providing 6.3% of the amphipods' carbon requirement. In microcosm populations, bacterial carbon accounted for between 1.7 and 5.2% of overall amphipod carbon demand, increasing with amphipod density and bioturbation.4. Ingestion rate, rather than the quantity of bacterial carbon in the sediment, was found to limit absorption of bacterial carbon from the sediment.
Monitoring lake recovery from point‐source eutrophication: the use of diatom‐inferred epilimnetic total phosphorus and sediment chemistry
Authors: ANDERSON N.J. , RIPPEY B. 
Published: May 2006

SUMMARY1. Diatom and geochemical responses to reduced nutrient loading were followed in a small, monomictic eutrophic lake in Northern Ireland by use of short sediment cores taken c. 15 years after redirection of creamery waste away from the lake.2. Epilimnetic total phosphorus (TP) concentrations (fig TP 1‐−1) were estimated for the period 1850–1990 using weighted averaging regression and calibration. Background TP levels, inferred using the diatom model, were c. 35μg TP 1‐−1 and increased to >140μg TP 1‐−1 in the late 1960s to early 1970s. Total P concentrations dropped to 80 μg TP 1‐−1 within 5 years of waste diversion (c. 1978–79), but varied between 1980 and 1990 (range 70–140 μg TP 1‐−1), perhaps due to internal loading, occasional continued disposal from the creamery and natural variations in stream P load.3. Diatom‐inferred TP concentrations were compared with monitored data where available, and the diatom model tended to overestimate TP concentrations by about 25 fig TP 1‐−1. Possible reasons for this are discussed (errors in the diatom model, stratigraphic variability, variability in the monitoring data).4. Post‐1980 geochemistry profiles (concentrations and accumulation rates) indicated some changes when compared with sediments deposited before 1980, perhaps reflecting the redirection of the creamery waste and reduced productivity of the lake (e.g. reduced calcium deposition). Phosphorus concentrations in the sediments changed very little over the last 150 years and, while sedimentary TP fluxes (g cm−2 yr−1) increase steadily up‐core, they do not record the effluent redirection in the mid‐1970s. There is, however, some indication of a slight lowering of P retention in the most recent sediments (1985–90).5. The general implications of such an approach to monitoring (i.e. the use of short cores) are discussed and the value of diatom‐inferred TP assessed. Diatom models offer the possibility of determining background TP concentrations and indicate that, despite the redirection of the creamery waste over 15 years ago, the pre‐creamery epilimnetic TP concentrations have not yet been reached.
Co‐inertia analysis: an alternative method for studying species–environment relationships
Authors: DOLÉDEC SYLVAIN , CHESSEL DANIEL 
Published: May 2006

SUMMARY

Methods used for the study of species–environment relationships can be grouped into: (i) simple indirect and direct gradient analysis and multivariate direct gradient analysis (e.g. canonical correspondence analysis), all of which search for non‐symmetric patterns between environmental data sets and species data sets; and (ii) analysis of juxtaposed tables, canonical correlation analysis, and intertable ordination, which examine species–environment relationships by considering each data set equally. Different analytical techniques are appropriate for fulfilling different objectives.
We propose a method, co‐inertia analysis, that can synthesize various approaches encountered in the ecological literature. Co‐inertia analysis is based on the mathematically coherent Euclidean model and can be universally reproduced (i.e. independently of software) because of its numerical stability. The method performs simultaneous analysis of two tables. The optimizing criterion in co‐inertia analysis is that the resulting sample scores (environmental scores and faunistic scores) are the most covariant. Such analysis is particularly suitable for the simultaneous detection of faunistic and environmental features in studies of ecosystem structure.
The method was demonstrated using faunistic and environmental data from Friday (Freshwater Biology 18, 87‐104, 1987). In this example, non‐symmetric analyses is inappropriate because of the large number of variables (species and environmental variables) compared with the small number of samples.
Co‐inertia analysis is an extension of the analysis of cross tables previously attempted by others. It serves as a general method to relate any kinds of data set, using any kinds of standard analysis (e.g. principal components analysis, correspondence analysis, multiple correspondence analysis) or between‐class and within‐class analyses.
Temporal and spatial environmental variability in the Upper Rhône River and its floodplain
Authors: CELLOT BERNARD , DOLE‐OLIVIER MARIE JOSÉ , BORNETTE GUDRUN , PAUTOU GUY 
Published: May 2006

SUMMARY

This paper develops a framework of spatial and temporal variability for a habitat typology of the Upper Rhône River (France) and its alluvial floodplain that is based on about 17 years of data collection and analysis. The aim was to provide a scale of spatial‐temporal variability for river habitat templet predictions on trends in species traits and species richness.
In developing this framework, eight physical‐chemical variables were available and could be considered for twenty‐two habitat types: seventeen superficial (surface) and five interstitial (0.5 m below the substrate surface). These habitat types were selected in two areas (Jons and Brégnier‐Cordon) after geomorphological considerations and because of differences in their biological characteristics.
The data sets used were processed by a ‘fuzzy coding’ method using, for each variable, the frequency distribution (by modalities = categories) of all measurements and monthly means over an annual scale. Two tables were produced; the first corresponded to an expression of the total variability, and the second represented an evaluation of the temporal variability.
Each of these tables was analysed by correspondence analysis, which provided factorial scores that were used to calculate, by habitat type and by variable, a total variability and a temporal variability in terms of cumulated variability of factorial scores for the eight physical–chemical variables. The rationale in describing variability from these two tables is that total variability equals temporal variability plus spatial variability. The spatial variability was then determined by the difference between total and temporal variability. From this procedure, a positioning of the twenty‐two habitat types on the spatial and temporal variability axes was obtained.
The estimate of spatial variability did not consider any error term that may have occurred in the above model; it was then tested by an independent assessment of the spatial variability using thirteen variables in nine major habitat types. A high correlation between the two ways of assessing spatial variability (r = 0.85, P < 0.004) underscored the reliability of the spatial variability that was calculated previously.
The river habitat templet obtained for the Upper Rhône and its alluvial floodplain appears to be appropriate to test the predictions on patterns of species traits and species richness in the framework of spatial and temporal variability.