Periphyton biomass and species composition in 21 British Columbia lakes: seasonal abundance and response to whole-lake nutrient additions

1984 ◽  
Vol 62 (5) ◽  
pp. 1022-1031 ◽  
Author(s):  
K. S. Shortreed ◽  
A. C. Costella ◽  
J. G. Stockner
Keyword(s):  
British Columbia ◽  
Species Composition ◽  
Dry Weight ◽  
Artificial Substrates ◽  
Seasonal Abundance ◽  
Dominant Group ◽  
Nitrogen And Phosphorus ◽  
Biomass Ash ◽  
Annual Carbon ◽  
Periphyton Biomass

Periphyton communities on artificial substrates in 21 oligotrophic British Columbia lakes were sampled from 1978 to 1980. Periphyton biomass (ash-free dry weight (AFDW) and total chlorophyll (Chl)) and accumulation rates (milligrams AFDW per square metre per day) were among the lowest recorded from temperate oligotrophic lakes, averaging from 0.01 to 5.69 mg Chl∙m−2, 0.04 to 2.86 g AFDW∙m−2, and 1 to 47 mg AFDW∙m−2∙day−1. Diatoms were the dominant group in most lakes at most times, comprising over 70% of total periphyton biomass. Achnanthes minutissima and Tabellaria flocculosa were the most ubiquitous species in the study, and Eunotia spp. were common only in acidic humic-stained lakes. Of the physical and chemical factors measured in this study, pH appeared to be most important in regulating diatom species composition. In those lakes fertilized with nitrogen and phosphorus, periphyton biomass showed marked increases over untreated years, but the community species composition in most lakes remained similar between treated and untreated years. Comparisons between artificial and natural substrates showed that the same species were common on both substrates, although relative abundances varied. The littoral zone of most study lakes is small relative to the pelagic, and it is estimated that periphyton comprised < 1% of average total algal biomass (as chlorophyll) and also represented < 1% of estimated total annual carbon metabolism.

Seasonal Cycle of Zooplankton off Southwestern British Columbia: 1979–89

1992 ◽  
Vol 49 (5) ◽  
pp. 903-921 ◽  
Author(s):  
David L. Mackas
Keyword(s):  
British Columbia ◽  
Species Composition ◽  
Continental Shelf ◽  
Late Summer ◽  
Dry Weight ◽  
Zooplankton Biomass ◽  
Late Spring ◽  
Washout Rate ◽  
Upwelled Water ◽  
Population Turnover

Average seasonal cycles of zooplankton biomass, species composition, and environmental conditions are estimated from 1979–89 samples collected off the southwest coast of British Columbia. Average total dry weight biomass ranges from a winter minimum <1.5 g/m2 to a late spring maximum >8 g/m2. Three subregions within the study area can be distinguished based on bathymetry and current pattern: the inner shelf banks, the shelf break and slope, and a gyre off the mouth of Juan de Fuca Strait. Total zooplankton biomass, species composition, and seasonality differ sharply between subregions, as do temperature, salinity, and nutrient and phytoplankton distributions. From spring through autumn, there are large inputs of upwelled water (and nutrients) to the continental shelf. Phytoplankton biomass is high, especially in mid- to late summer, and is ample to support growth of herbivorous zooplankton. Despite high food availability and relatively low predation pressure, surface layer zooplankton populations decline on the continental shelf from late spring through autumn, while offshore zooplankton populations increase slowly. A high washout rate due to upwelling and subsequent seaward and alongshore transport is the most plausible explanation. For the continental shelf in summer, the advective component of population turnover is probably larger than local predation mortality.

Periphyton Biomass and Species Composition in a Coastal Rainforest Stream in British Columbia: Effects of Environmental Changes Caused by Logging

1983 ◽  
Vol 40 (11) ◽  
pp. 1887-1895 ◽  
Author(s):  
Ken S. Shortreed ◽  
John G. Stockner
Keyword(s):  
British Columbia ◽  
Light Intensity ◽  
Species Composition ◽  
Environmental Changes ◽  
Stream Temperature ◽  
Vancouver Island ◽  
Accumulation Rates ◽  
Ion Concentrations ◽  
Periphyton Biomass ◽  
Clearcut Logging

Periphyton biomass, species composition, and accumulation rates on Plexiglas substrates were determined in a 6-yr study from 1974 to 1979 in Carnation Creek, Vancouver Island, B.C. During the first 2 yr of the study, the watershed was unlogged. Clearcut logging during the remainder of the study resulted in increases in light intensity of over 100% at some sites, slight increases in stream temperature (2–3 °C in summer) and increases in some dissolved ion concentrations. Phosphorus concentrations were similar throughout the study. Diatoms were the most common class of algae, and Achnanthes minutissima and Synedra rumpens were the most common diatoms. Filamentous chlorophytes (predominantly Mougeotia sp. with some Draparnaldia sp., Spirogyra sp., and Zygnema sp.) occurred sporadically throughout the study but were more common after logging, primarily as a result of increased light intensity. Although highest recorded periphyton biomass and accumulation rates occurred after logging, post-logging values were generally similar to those recorded prior to logging. We attributed this to the lack of increase in phosphorus concentrations after logging.

Black flies (Diptera: Simuliidae) from Hardwicke Island, British Columbia

1982 ◽  
Vol 60 (12) ◽  
pp. 3364-3369 ◽  
Author(s):  
Jerome L. Mahrt
Keyword(s):  
British Columbia ◽  
Species Composition ◽  
Abundant Species ◽  
Seasonal Abundance ◽  
Black Flies ◽  
Black Fly

Nineteen species of immature simuliids (Diptera: Simuliidae) were collected from streams on Hardwicke Island in the Johnstone Straits of British Columbia. These species were Simulium aureum Fries, S. canadense Hearle, S. decorum Walker, S. hunteri Malloch, S. tuberosum Lundström complex, S. venustum Say – verecundum, Stone and Jamnback complex, Prosimulium dicum Dyar and Shannon, P. esselbaughi Sommerman, P. formosum Shewell, P. travisi Stone, Simulium anatinum Wood, S. bafftnense Twinn group, S. bicorne Dorogostajskij, Rubtzov and Vlasenko complex, S. gouldingi Stone, S. piperi Dyar and Shannon, S. pugetense (Dyar and Shannon), S. vernum Macquart complex, Prosimulium doveri Sommerman, and Stegopterna sp. Enderlein. The last nine species have not been reported previously from British Columbia. Species composition, succession, and seasonal abundance of larvae and pupae were determined from April to August of 1980 and 1981. Simulium venustum–verecundum complex and S. hunteri were the most abundant species in 1980, while S. hunteri and S. vernum complex were most abundant in 1981. Black fly productivity was greatly reduced in 1981.

Carabidae of Barnaul city parks: ecological characteristics and species composition

2018 ◽  
Vol 8 (2) ◽  
pp. 348-353
Author(s):  
E. A. Kuchina ◽  
N. D. Ovcharenko ◽  
L. D. Vasileva
Keyword(s):  
Species Composition ◽  
Diversity Index ◽  
Similarity Index ◽  
Life Forms ◽  
Ground Beetles ◽  
Forest Steppe ◽  
Ecological Groups ◽  
Dominant Group ◽  
Species Diversity Index ◽  
Steppe Species

<p>Anthropogenic impact on the population of ground beetles leads to a change in their numbers, structure of dominance, density, species composition, spectrum of life forms. This makes the beetles Carabidae a convenient and informative bioindicator of the ecological state of biocenoses. The material for this work was the Carabidae collections conducted in June-August 2016-2017 in the park zone of different regions of Barnaul, differing in location, area, hydrological regime, vegetation cover, purpose and anthropogenic load. When processing the material, the quantitative, species and generic composition of the carabidae was determined, calculations were made for such indicators as the Berger-Parker dominance index, the Shannon species diversity index (Hs), and the Jacquard species similarity index. The fauna (Coleoptera, Carabidae) of the park zone of Barnaul is represented by 55 species belonging to 20 genera. The dominant group is represented by species belonging to steppe, forest and polyzonal groups. Forest-steppe species of ground beetles as dominants have not been identified in any of the investigated territories. The greatest variety of ecological groups was noted on the territory of the Yubileyny рark, which is explained by the presence of zones with various microclimatic conditions, the presence of a birch grove that flows through the park with the Pivovarka River, and a wide log in the park. Registered species belong to eight groups of life forms belonging to two classes - zoophagous and myxophytophagous. On the numerical and species abundance, zoophages predominate. The spectrum of life forms corresponds to the zonal spectrum characteristic of the forest-steppe zone.</p><p> </p>

Potential Contribution of Nutrients and Polycyclic Aromatic Hydrocarbons from the Creeks of Cootes Paradise Marsh

1996 ◽  
Vol 31 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Barb Crosbie ◽  
Douglas Bryant ◽  
Brian McCarry
Keyword(s):  
Aromatic Hydrocarbons ◽  
Laboratory Experiments ◽  
Dry Weight ◽  
Common Source ◽  
Potential Contribution ◽  
Nitrogen And Phosphorus ◽  
Engine Combustion ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Derivatives Of

Abstract During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.

Bacterioplankton, Phytoplankton, and Zooplankton Communities in a British Columbia Coastal Lake Before and After Nutrient Reduction

1986 ◽  
Vol 43 (8) ◽  
pp. 1504-1514 ◽  
Author(s):  
F. Joan Hardy ◽  
Ken S. Shortreed ◽  
John G. Stockner
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Growing Season ◽  
Nutrient Reduction ◽  
Nitrogen And Phosphorus ◽  
Coastal Lake ◽  
Before And After ◽  
High Concentrations

Inorganic nitrogen and phosphorus were applied weekly during the growing season from 1980 to 1982 and twice weekly in 1983 to Hobiton Lake, a warm monomictic coastal lake in British Columbia. The lake was not fertilized in 1984. Average numbers of bacteria during the growing season decreased from a high of 1.53 × 106∙mL−1 in the fertilized condition to 0.84 × 106∙mL−1 in the unfertilized condition. Chlorophyll a concentrations decreased from a maximum seasonal average of 2.69 μg∙L−1 (1981) to 1.30 μg∙L−1 (1984), and algal numbers decreased from 5.83 × 104∙mL−1 (1983) to 2.29 × 104∙mL−1 (1984). Although the numbers of phytoplankton in each size fraction (picoplankton, nanoplankton, or microplankton) decreased in the unfertilized condition, the greatest change was an almost fourfold decrease in picoplankton, which consisted of 90% cyanobacteria (primarily Synechococcus spp.). Abundance of the large diatoms Rhizosolenia spp. and Melosira spp. increased in 1984, resulting in an increase in average seasonal algal volume. Average densities of medium (0.15–0.84 mm) and large (0.85–1.5 mm) zooplankton were greatest in 1982, while rotifers and small zooplankton (0.10–0.14 mm) were most dense in 1984 following nutrient reduction. The lake had relatively high concentrations of planktivorous juvenile sockeye salmon (Oncorhynchus nerka) that appeared to minimize any direct effect of nutrient additions on zooplankton densities.

scholarly journals The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea Mays L.) in Southeastern Poland

2011 ◽  
Vol 51 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Halina Kucharczyk ◽  
Paweł Bereś ◽  
Zbigniew Dąbrowski
Keyword(s):  
Zea Mays ◽  
Species Composition ◽  
Seasonal Dynamics ◽  
Food Source ◽  
Zea Mays L ◽  
Maize Plant ◽  
Seasonal Abundance ◽  
Immature Stages ◽  
Thrips Species

The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea MaysL.) in Southeastern PolandThrips species composition and seasonal abundance was studied on maize crops during two seasons (2006-2007), in southeastern Poland. Altogether 21 species have been identified, among themFrankliniella tenuicornis(Uzel 1895) andHaplothrips aculeatus(Fabricius 1803) which are a graminicolous species and were eudominants, comprising 96.8% in 2006 and 82.0% in 2007 of all collected specimens. Other species occurred only in low numbers. The frequent and numerous presence ofF. tenuicornisspecies in their immature stages in the samples, confirmed the role of the maize plant as the host.H. aculeatusprobably chose maize as a food source and substitute plant for breeding.

scholarly journals Questing ixodid ticks on the vegetation of sable antelope and multi-herbivore enclosures in Thabazimbi

2015 ◽  
Vol 86 (1) ◽  
Author(s):  
André C. Uys ◽  
Ivan G. Horak ◽  
Alan Harrison
Keyword(s):  
Species Composition ◽  
Ixodid Tick ◽  
Tick Control ◽  
Ixodid Ticks ◽  
Seasonal Abundance ◽  
First Year ◽  
Potential Vector ◽  
The Face ◽  
Tick Borne Disease ◽  
Grassland Habitats

This survey of ixodid ticks was the first to compare the species composition and population dynamics of free-living ticks in intensive, sable antelope breeding enclosures, now commonplace in commercial wildlife ranching in South Africa, with those of multi-herbivore enclosures. The species composition, abundance and seasonal abundance of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelope (Hippotragus niger), on which strategic tick control is practised, were compared with those of ticks in a multi-species herbivore enclosure surrounding the breeding enclosures in which no tick control is practised. A total of eight ixodid tick species were collected by drag-sampling the woodland and grassland habitats in each enclosure type monthly from July 2011 to July 2013. Rhipicephalus decoloratus, a potential vector of fatal tick-borne disease in sable antelopes, was the most abundant, accounting for 65.4% of the total number of ticks collected in the sable enclosures, whilst representing only 25.4% of number of ticks collected in the multi-species herbivore enclosure. Rhipicephalus decoloratus and R. evertsi evertsi were more abundant than R. appendiculatus (both p < 0.05) and Amblyomma hebraeum (p < 0.001 and p < 0.01, respectively). Rhipicephalus decoloratus larvae were collected throughout the year, with peak collections in November 2012 and October to December 2013 in the sable enclosures; and in April/May 2012 and February/April 2013 in the multi-species herbivore enclosure. More R. decoloratus were recovered in the second year than in the first year in the grassland habitat of the sable enclosures (V = 7.0, p < 0.05) possibly as a result of acaricide resistance. The apparent temporal over-abundance of R. decoloratus in sable antelope breeding enclosures, in the face of strategic tick control, is of concern and requires further investigation.

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