Estimates of annual production for some aquatic insects from the La Trobe River, Victoria

1986 ◽  
Vol 37 (2) ◽  
pp. 113 ◽  
Author(s):  
R Marchant
Keyword(s):  
Aquatic Insects ◽  
Temperate Zone ◽  
Annual Production ◽  
Frequency Method ◽  
Habitat Temperature ◽  
Size Frequency ◽  
Total Annual Production ◽  
Annual Turnover

Annual production was estimated by the size-frequency method for Ephemeroptera (Tasmanocoenis tonnoiri, two species of Baetis, Atalonella spp., Atulophlebioides sp.), Plecoptera (Leptoperla spp.) and Trichoptera (Ecnomus sp.) at four sites on the lowland section of the La Trobe River. Annual production (P) of individual ephemeropteran species (or genera) varied from 0.02 to 0.7 g m-2 while total annual production of this order at two sites was 0.7-1 . 5 g m-. Annual production of Leptoperla spp. was 0.03 g m-2 at one site while Ecnomus sp, averaged 2 g m-2 at two sites. Estimates of annual production were subject to an error of at least t 50%. Annual turnover ratios (P/B; B is mean biomass) varied from 9 to 19 and were three to four times higher than published values for similar-sized macroinvertebrates in the temperate zone (generally < 15°C mean annual habitat temperature). This probably resulted from the higher average temperatures (17-18°C) at most sites.

Production of the amphipod Hyalella azteca (Saussure) in a northern Ontario lake

1983 ◽  
Vol 61 (9) ◽  
pp. 2051-2059 ◽  
Author(s):  
Dorothy H. Lindeman ◽  
Walter T. Momot
Keyword(s):  
Littoral Zone ◽  
Lake Ontario ◽  
Hyalella Azteca ◽  
Dry Weight ◽  
Annual Production ◽  
Frequency Method ◽  
Northern Ontario ◽  
Habitat Temperature ◽  
Size Frequency ◽  
Annual Biomass

Annual production of the amphipod, Hyalella azteca, was estimated in three habitats of the upper littoral zone of Dock Lake, Ontario, over a 2-year period (1980–1981). Cohort production (P) by the size frequency method was 1.39 g/m2 (dry weight), mean annual biomass (B) was 0.36 g/m2, and the P/B ratio was 3.9 for the 1980 year class. Five other methods for estimating production were applied to this cohort, providing comparable estimates ranging from 1.21 (instantaneous growth) to 1.65 (cohort G) g/m2. Size frequency estimates of annual production for 1980 and 1981 were 1.24 and 1.40 g/m2, respectively. The annual P/[Formula: see text] ratios of 3.9 and 4.0 for these 2 years agree with the cohort value. A comparison of production estimates for Hyalella azteca in the literature shows a gradient of production which correlates with the habitat temperature regime.

Annual Production by Caddisflies and Mayflies in a Western Minnesota Plains Stream

1982 ◽  
Vol 39 (12) ◽  
pp. 1628-1635 ◽  
Author(s):  
M. B. MacFarlane ◽  
T. F. Waters
Keyword(s):  
Standing Stock ◽  
Annual Production ◽  
Insect Community ◽  
Downstream Site ◽  
Frequency Method ◽  
Third Order ◽  
Upstream Site ◽  
Size Frequency ◽  
Total Annual Production ◽  
Wet Weight

Annual production was estimated for five species of caddisflies and mayflies, comprising major components of the insect community, in the Redwood River, a second- to third-order plains stream in western Minnesota. Estmates were made at two sites, one above and one below an impoundment. At the upstream site, annual production (g∙m−2, wet weight) and annual P/B ratios (in parentheses) were Hydropsyche bifida, 8.3 (6.9); Cheumatopsyche pettiti, 5.5 (7.0); Stenonema nepotellum, 3.4 (5.7); Stenacron interpunctatum canadense, 0.8 (7.0); and Caenis simulans, 4.7 (4.2); with total annual production of 22.7 g∙m−2. At the downstream site, annual production and P/B ratios were H. bifida, 34.3 (4.4); C. pettiti, 68.5 (4.4); S. interpunctatum canadense, 24.1 (6.1); and C. simulans, 2.8 (4.4); with total annual production of 129.7 g∙m−2. These species comprised 27.5% of the total insect standing stock at the upstream site and 75.9% downstream. The hydropsychid production at the downstream site was apparently sustained by the drift of zooplankton from the impoundment, resulting in considerably higher production by hydropsychids than reported in woodland streams.Key words: production, Trichoptera, Ephemeroptera, plains stream, benthos, size–frequency method

Life spans of two species of tropical mayfly nymph (Ephemeroptera) from Magela Creek, Northern Territory

1982 ◽  
Vol 33 (1) ◽  
pp. 173 ◽  
Author(s):  
R Marchant
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Northern Territory ◽  
Annual Production ◽  
Length Frequency ◽  
Frequency Method ◽  
B Values ◽  
Size Frequency ◽  
Mayfly Nymph ◽  
Growth And Reproduction

The nymphs of Cloeon fuviatile and a species of Tasmanocoenis were common in the shallows (< 1 m) of two billabongs in Magela Creek, Northern Territory. Monthly estimates of abundance and length frequency showed that growth and reproduction occurred continuously. Estimates of the ratio of annual production to mean biomass (PIB) were calculated with the size-frequency method, using different values for nymphal life span; these estimates, when compared with P/B values predicted from the literature, suggested that the nymphs had a life span of about 1 month. Such a rapid life cycle is at least in part the result of the high mean temperature (30°C) in the shallows.

Population and Production Dynamics of an Enchytraeid Worm in a Subtropical Blackwater River

1987 ◽  
Vol 44 (8) ◽  
pp. 1469-1474 ◽  
Author(s):  
David L. Stites
Keyword(s):  
Aquatic Insect ◽  
Dry Mass ◽  
Coarse Sand ◽  
Annual Production ◽  
Total Density ◽  
Frequency Method ◽  
Blackwater River ◽  
Size Frequency ◽  
Center Channel ◽  
Production Dynamics

Population and production dynamics of Barbidrilus paucisetus Loden and Locy (Oligochaeta: Enchytraeidae) in a sixth-order blackwater river are described. This worm was the dominant member of the meiofauna of the sand habitat, accounting for 50–90% of the total density. Population density varied seasonally, increasing from < 20 000/m2 in the winter to 60–120 000/m2 in the summer. Biomass averaged 145 mg dry mass/m2 with a range of 8–326 mg/m2. Density peaked in the clean coarse sand of the center channel areas and was lower where the sand was finer and where more organic matter was present. Size frequency histograms indicated that there were three recruitment peaks during the sampling year, with mature and new individuals present in all seasons. Annual production (2.12 g dry mass/m2, SE = 0.15 g/m2), was estimated using the size frequency method and a cohort production interval correction of 3. Annual production was low compared with that of terrestrial Enchytraeidae and comparable with that of many aquatic insect species. Annual production/biomass ratio (14.3) was higher than terrestrial Enchytraeidae, due to the comparatively short generation time of this species.

Use of the Size–Frequency (Hynes) Method to Estimate Annual Production of a Stream Fish Population

1983 ◽  
Vol 40 (11) ◽  
pp. 2030-2034 ◽  
Author(s):  
Greg C. Garman ◽  
Thomas F. Waters
Keyword(s):  
Salmo Trutta ◽  
Fish Population ◽  
Annual Production ◽  
Salmo Gairdneri ◽  
Frequency Method ◽  
Reliable Determination ◽  
Size Frequency ◽  
Production Values ◽  
Significant Difference

Previously developed and accepted methods of fish production estimation, such as instantaneous growth (G method), require aging of sampled individuals. Hynes' size–frequency method, however, does not require cohort separation. Annual production and approximate 95% confidence intervals are presented and compared for populations of brook, brown, and rainbow trout (Salvelinus fontinalis, Salmo trutta, and Salmo gairdneri) in Valley Creek, Minnesota, 1977–78, using the size–frequency and G methods. No significant difference was found between production values calculated by the two methods. It is proposed that the size–frequency method provides a reliable determination of annual production of fish populations and will be especially useful where accurate aging of individuals is not possible or where aging represents excessive labor.

Regrowth of smooth bromegrass (Bromus inermis Leyss.) following defoliation

1994 ◽  
Vol 74 (3) ◽  
pp. 531-537 ◽  
Author(s):  
T. Harrison ◽  
J. T. Romo
Keyword(s):  
Vegetative Growth ◽  
Early Spring ◽  
Bromus Inermis ◽  
Annual Production ◽  
Growth Stages ◽  
Forage Production ◽  
Smooth Bromegrass ◽  
Total Annual Production ◽  
Growing Conditions ◽  
Reproductive Phases

Regrowth and production of tillers in smooth bromegrass (Bromus inermis Leyss.) following defoliation to a 5-cm stubble height were monitored throughout the summer and in early spring the following year in central Saskatchewan. After defoliation, while smooth bromegrass was vegetative, forage began accumulating in 45–75 growingdegree-days (GDD) when moisture was favorable. Regrowth ranged from 34 to 84 g m−2. Plants also produced ≤ 51 g m−2 of regrowth when defoliated at or before culm elongation in a year with above-average precipitation. In two dry years, regrowth was minimal and plants did not regrow after defoliation in the later vegetative growth stages; however, new leaves were produced within 110–140 GDD. Following defoliation at early vegetative growth stages, 1030–1180 GDD were needed to reach maximum regrowth. Total annual production was either unaffected or reduced by defoliation. Total annual production ranged from 35 to 139 g m−2, with yields lowest when defoliated in early May or early June and highest when herbage was removed in mid-May or near flowering and seed production. When plants were defoliated during vegetative growth most tillers were produced the following spring, whereas when plants were defoliated during reproductive phases the majority of tillers emerged in the fall. The year after defoliation, the density of tillers (871–951 m−2) was not significantly different among treatments. Regrowth following defoliation cannot be related to a particular growth stage, but rather it depends on growing conditions. If smooth bromegrass is defoliated once and rested until the next year, it should be recovered by early spring and its productivity should be unaffected. Key words: Etiolated growth, forage production, grazing management, regrowth, rest requirement, tillering

Life history, secondary production and population dynamics of Gammarus fossarum (Koch, 1836) in a constant temperature stream

Biologia ◽  
2012 ◽  
Vol 67 (1) ◽  
Author(s):  
Pavel Beracko ◽  
Anna Sýkorová ◽  
Andrej Štangler
Keyword(s):  
Life Cycle ◽  
Constant Temperature ◽  
Growth Function ◽  
Dry Mass ◽  
Frequency Method ◽  
Daily Growth ◽  
Gammarus Fossarum ◽  
Frequency Distributions ◽  
Size Frequency ◽  
The Mean

AbstractPopulation of the freshwater amphipod Gammarus fossarum was investigated in a calcareous stream with almost constant temperature (7–8°C) in the Chočské Vrchy Mts (West Carpathians, Slovakia). Quantitative samples of G. fossarum taken during 2005 showed population densities varying from 100 m−2 in August to 585 m−2 in late November. The population was split into juveniles, mature males, mature females without eggs and females with eggs. The percentage of juveniles (40–64%) was always the highest of any of the categories. Ovigerous females occurred throughout the year. The mean sex ratio was 1: 2.4 (male: female), although its values varied considerably with the time of year. Breeding was continuous, although juvenile recruitment peaked in early spring, summer and early winter. Three discrete cohorts were distinguished from the size frequency distributions. The life span was 6–7 months and the individuals matured approximately in the half of life cycle. The mean fecundity was 9.6 embryos per brood. Variation in fecundity was mostly explained by size of the incubating females. The absolute growth of this species was best described by the Gompertz growth function. Relative growth rates (% body DM day−1) fluctuated in a nonlinear manner with size and age. The highest values of daily growth (2–4% of dry mass per day) were noted approximately in the half of life cycle. Annual production, estimated by the size-frequency method, was 1618.9 g dry mass m−2 and P/B ratio was 5.15.

Production and Movement of Juvenile Rainbow Trout (Salmo gairdneri) in a Headwater of Bothwell's Creek, Georgian Bay, Canada

1974 ◽  
Vol 31 (1) ◽  
pp. 117-121 ◽  
Author(s):  
D. Ross Alexander ◽  
Hugh R. MacCrimmon
Keyword(s):  
Rainbow Trout ◽  
Great Lakes ◽  
Annual Production ◽  
Salmo Gairdneri ◽  
Ecological Disturbance ◽  
Georgian Bay ◽  
Juvenile Rainbow Trout ◽  
Total Annual Production ◽  
Calculated Ratio

Within the 21,500 m2 headwater, the standing population of juvenile rainbow trout reached a high of 7.05 g/m2 in October. Production was maximum during August at 1.77 g/m2. Total annual production is calculated at 284.5 kg (13.2 g/m2). Spring emigrants (no less than 4830 fish weighing 69 kg) were age I (91%) and age II. Minimum calculated ratio of production to yield as emigrants was 4.1:1. Comparatively few age 0 fish emigrated during summer. Because of their demonstrated capability to produce juveniles, sensitive headwaters must be preserved from ecological disturbance to assure self-perpetuating rainbow trout populations in the Great Lakes.

Assessment of strains of Bradyrhizobium sp. (Lupinus) for serradellas (Ornithopus spp.)

1996 ◽  
Vol 36 (1) ◽  
pp. 63 ◽  
Author(s):  
RA Ballard
Keyword(s):  
Nitrogen Fixation ◽  
Sandy Soils ◽  
Fold Increase ◽  
Annual Production ◽  
Total Annual Production ◽  
Bradyrhizobium Sp ◽  
Commercial Inoculant ◽  
Inoculant Strain ◽  
Early Production

Several strains of Bradyrhizobium sp. (Lupinus) were compared, in the glasshouse and field, with the Australian commercial inoculant strain, WU42.5, for symbiotic performance on serradella. Strains WSM471 and USDA3709 were more effective in nitrogen fixation (12 and 8% respectively) than WU42.5 across 10 serradella lines, although WU42.5 generally displayed good levels of effectiveness. WSM471 was a more saprophytically competent strain than WU425 in mildly acidic sandy soils, resulting in a 2.8-fold increase in the nodule score of serradella sown 32 cm from a line of bradyrhizobia established the previous year. Although WSM471, when compared with WU42.5, increased the nodulation and early production of an established sward of serradella, it did not improve total annual production of the sward. The possible replacement of WU42.5 with WSM471 in serradella inoculants is discussed.

Life history and production of Ephoron album (Say) (Ephemeroptera: Polymitarcidae) in the Valley River, Manitoba

1985 ◽  
Vol 63 (7) ◽  
pp. 1668-1674 ◽  
Author(s):  
D. J. Giberson ◽  
T. D. Galloway
Keyword(s):  
Dry Weight ◽  
Exposure Period ◽  
Summation Method ◽  
Instantaneous Growth Rate ◽  
Frequency Method ◽  
Instantaneous Growth ◽  
Size Frequency ◽  
Curve Method ◽  
Rate Method ◽  
Valley River

Ephoron album was the dominant summer mayfly in shallow riffles in the agricultural zone of the Valley River, Manitoba, in 1982 and 1983. There was one generation per year; eggs deposited in August hatched in late May of the following year and nymphs developed rapidly during the summer months. The eggs required a cold period to promote hatching and hatching success of eggs treated in the laboratory at −2 °C for varying periods of time was positively correlated to the length of the exposure period. No eggs hatched following exposure to 4 or 10 °C. Production for 1982 was estimated by four methods for the production interval of only 72 days: the instantaneous growth rate method (1.32 ± 0.44 g fresh dry weight∙m−2∙year−1), the Allen curve method (1.32 g∙m−2∙year−1), the removal – summation method (1.43 ± 0.41 g∙m−2∙year−1), and the size–frequency method (1.48 ± 0.51 g∙m−2∙year−1). Confidence intervals (95%) were calculated using the method of C. C. Krueger and F. B. Martin for the size–frequency estimate of production and by bootstrapping for the removal–summation and instantaneous growth estimates.

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