Preliminary Energy Budget of the Ninespine Stickleback (Pungitius pungitius) in an Arctic Lake

1973 ◽  
Vol 30 (8) ◽  
pp. 1179-1189 ◽  
Author(s):  
J. N. Cameron ◽  
J. Kostoris ◽  
P. A. Penhale
Keyword(s):  
Energy Budget ◽  
Population Distribution ◽  
Growth Efficiency ◽  
Early Summer ◽  
First Year ◽  
Pungitius Pungitius ◽  
Feeding Experiments ◽  
Flow Through ◽  
Clearing Rate ◽  
Northern Alaska

In a study of energy flow through the stickleback population of Ikroavik Lake, northern Alaska, oxygen consumption was related to weight and temperature by the equation Log Y = −2.795 +.823 W +.094 T where Y = μl∙min−1O2 uptake; W = log weight, mg; and T = temperature. Growth was fairly rapid, with fish reaching about 21 mm at the end of the first year, 42 mm by the second, and 65 mm by the third. No older fish were found. Food was primarily chironomid larvae and zooplankton, especially copepods and Daphnia. Estimates of daily ration were calculated from growth and metabolic data (23.4 cal/day for a 30-mm fish at 10 C), gastric clearing rate determinations (12.2 cal/day at 15 C), and laboratory feeding experiments (24 cal/day at 10 C). Population distribution was uneven. Higher densities were reached in early summer, up to 74 g/m2 in the marginal marsh areas. For specified days when temperatures were accurately known, an energy budget could be calculated for the population in given areas, including estimates of population biomass, respiration, growth, ration, and growth efficiency.

scholarly journals MANAGEMENT OF LATE SPRING-EARLY SUMMER PASTURE SURPLUSES IN HILL COUNTRY

1984 ◽  
pp. 199-206 ◽  
Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly
Keyword(s):  
Early Spring ◽  
Early Summer ◽  
Late Spring ◽  
First Year ◽  
Hill Country ◽  
Continuous Grazing ◽  
Summer Pasture ◽  
Animal Performances ◽  
Grazing Policy ◽  
Made In

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control

THE CONSUMPTION OF EUPHORBIA CYPARISSIAS (EUPHORBIACEAE) BY LARVAE OF CELERIO EUPHORBIAE (LEPIDOPTERA: SPHINGIDAE)

1971 ◽  
Vol 103 (1) ◽  
pp. 59-66 ◽  
Author(s):  
T. R. New
Keyword(s):  
Energy Budget ◽  
Preliminary Data ◽  
Dry Weight ◽  
Field Conditions ◽  
Close Similarity ◽  
Feeding Experiments ◽  
Laboratory Results ◽  
Infested Site ◽  
Euphorbia Cyparissias

AbstractLaboratory feeding experiments on Celerio euphorbiae (L.) showed that each larva consumed about 2.7 g dry weight of Euphorbia cyparissias L. Laboratory-reared and field-collected larvae produced pupae of similar weights and the close similarity between the fresh and dry weights of control-fed larvae and larvae allowed to feed freely indicates that laboratory results are readily extrapolated to field conditions. On one infested site, at Braeside, Ont., the amount of spurge foliage was measured and the density of larvae needed to graze it fully was estimated at 14/m2 completing development. Preliminary data on an energy budget of the larva are discussed in relation to possible damage to the plant.

The production and persistence of grazed irrigated pasture mixtures in south-eastern Queensland

1968 ◽  
Vol 8 (31) ◽  
pp. 177 ◽  
Author(s):  
RJ Jones ◽  
Davies J Griffiths ◽  
RB Waite ◽  
IF Fergus
Keyword(s):  
White Clover ◽  
Dry Matter ◽  
Rest Period ◽  
Early Summer ◽  
Temperate Species ◽  
First Year ◽  
Nitrogen Levels ◽  
South Eastern ◽  
Key Species ◽  
Significant Difference

Five irrigated pasture mixtures (four containing tropical and temperate species and one containing only temperate species (winter mixture) ) were compared under grazing at three nitrogen levels -nil, 100, and 300 lb N an acre a year as urea-over a four-year period 1960-1963. Pastures were grazed for approximately one week every six weeks with a twelve-week rest period in the winter of 1962 and 1963. Under this management mean annual yields of dry matter increased from 15,700 lb to 25,000 lb an acre over the four-year period. Pasture growth rates varied from over 90 lb DM an acre a day in early summer to 10-40 lb DM an acre a day in winter due to variations in radiation and temperature. Urea increased pasture dry matter yields and also the yields of nitrogen measured in 1961 and 1962. Mean response was 19 lb and 14.5 lb DM/lb N applied at the N100 and N300 rates respectively. Yield of nitrogen was increased by a mean of 79 lb an acre a year by application of urea, but there was no significant difference between rates. Dry matter responses to urea were small in winter and spring and large in summer and autumn. The N300 rate reduced the yield of white clover in the first two years of the pasture, but there was no reduction in the yield of white clover at the N100 rate compared with the N0 treatment. There were no significant differences in yield between the pasture mixtures in the establishment year. In subsequent years mixtures containing summer and winter species outyielded (P<0.001) the winter mixture, particularly in summer and autumn. The pattern of production was similar for all mixtures and there was no significant difference between mixtures in yield of nitrogen. Chloris gayana Kunth CV. Samford and Setaria sphacelata (Schum) Stapf and C. E. Hubbard CV. Nandi. were the most successful summer grasses and Bromus unioloides (Willd.) H.B.K. cv. Priebes, the best winter grass. Three Paspalum species failed to compete with the Setaria and three winter grasses were low yielding after the first year. Trifolium repens L. CV. Ladino was the only successful legume of three winter and three summer legumes sown. It enabled yields of 400 lb N an acre a year to be achieved, increased total soil nitrogen, and made an estimated contribution of 760-810 lb N an acre over the four-year period. It is considered to be the key species for irrigated pastures in south-eastern Queensland.

Investigation of flowering in Banksia baxteri R. Br. and B. hookeriana Meissner for improving pruning practices

1994 ◽  
Vol 34 (8) ◽  
pp. 1209 ◽  
Author(s):  
LJ Rohl ◽  
AM Fuss ◽  
JA Dhaliwal ◽  
MG Webb ◽  
BB Lamont
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Floral Development ◽  
Early Summer ◽  
Stem Length ◽  
First Year ◽  
Floral Initiation ◽  
Scanning Electron

Floral initiation and development in relation to time of flowering were investigated in Banksia baxteri and B. hookeriana with the aid of scanning electron microscopy. Floral initiation occurred in spring in B. baxteri and in early summer in B. hookeriana. Floral development was rapid in B. baxteri (3 months to reach anthesis in summer). In B. hookeriana, development took 5 months, with anthesis occurring in winter. Most B. hookeriana blooms were produced on 2-year-old shoots, while B. baxteri produced about half of its blooms on 2-year-old shoots and almost as many on 3-year-old shoots. In both species, shoots that flowered within 2 years were longer and thicker in their first year than other shoots. A critical minimum stem length was determined for the first year's growth, to be used as a criterion for determining which shoots to remove during pruning. Details are provided for the timing of pruning to achieve maximum bloom production in B. baxteri and B. hookeriana.

scholarly journals Predicting Melt Pond Fraction on Landfast Snow Covered First Year Sea Ice from Winter C-Band SAR Backscatter Utilizing Linear, Polarimetric and Texture Parameters

2018 ◽  
Vol 10 (10) ◽  
pp. 1603 ◽  
Author(s):  
Saroat Ramjan ◽  
Torsten Geldsetzer ◽  
Randall Scharien ◽  
John Yackel
Keyword(s):  
Sea Ice ◽  
Regression Models ◽  
Incidence Angle ◽  
Early Summer ◽  
Aerial Photographs ◽  
Late Winter ◽  
First Year ◽  
Melt Pond ◽  
Texture Parameters ◽  
Snow Thickness

Early-summer melt pond fraction is predicted using late-winter C-band backscatter of snow-covered first-year sea ice. Aerial photographs were acquired during an early-summer 2012 field campaign in Resolute Passage, Nunavut, Canada, on smooth first-year sea ice to estimate the melt pond fraction. RADARSAT-2 Synthetic Aperture Radar (SAR) data were acquired over the study area in late winter prior to melt onset. Correlations between the melt pond fractions and late-winter linear and polarimetric SAR parameters and texture measures derived from the SAR parameters are utilized to develop multivariate regression models that predict melt pond fractions. The results demonstrate substantial capability of the regression models to predict melt pond fractions for all SAR incidence angle ranges. The combination of the most significant linear, polarimetric and texture parameters provide the best model at far-range incidence angles, with an R 2 of 0.62 and a pond fraction RMSE of 0.09. Near- and mid- range incidence angle models provide R 2 values of 0.57 and 0.61, respectively, with an RMSE of 0.11. The strength of the regression models improves when SAR parameters are combined with texture parameters. These predictions also serve as a proxy to estimate snow thickness distributions during late winter as higher pond fractions evolve from thinner snow cover.

The biology of Barleeia unifasciata (Gastropoda:Prosobranchia) in red algal turfs in S.W. Ireland

1982 ◽  
Vol 62 (2) ◽  
pp. 461-468 ◽  
Author(s):  
T. Southgate
Keyword(s):  
Sexual Development ◽  
Algal Species ◽  
Late Summer ◽  
Early Summer ◽  
First Year ◽  
Maximum Life Span ◽  
Red Algal ◽  
Second Year ◽  
Recruitment Period ◽  
Length Frequency Data

Variation in the abundance of Barleeia unifasciata is compared in several red algal species between June 1978 and June 1980 at Cooskeen Cove, Bantry Bay, Ireland. Population abundance in all algae varied seasonally, exhibiting a cycle of late-summer to autumn maxima, with winter to early summer minima. Greatest abundance was recorded in those algae which formed compact turf-like growths suitable for the entrapment of diatoms and detrital material and provided greatest shelter from wave-crash. Length frequency data showed the main recruitment period to be late June-October with a peak in August with juveniles present in all months of the year. Maximum life span was shown to be 2 years or more with only 15 % of the population surviving into the second year. Sexual development and reproductive cycle was determined for 0 + and 1 + animals. Mature males produced sperm continuously throughout the year. Not all 0 + females spawned in their first year. Summer spawning 0 + females exhibited reduced sexual activity in October and spawned again in the following summer. Some 1 + females spawned in winter and spring. Delayed sexual development in some individuals of both sexes was related to late hatching.

scholarly journals The energetics of flow through a rapidly oscillating tube with slowly varying amplitude

2011 ◽  
Vol 369 (1947) ◽  
pp. 2989-3006 ◽  
Author(s):  
Robert J. Whittaker ◽  
Matthias Heil ◽  
Sarah L. Waters
Keyword(s):  
Flow Structure ◽  
Energy Budget ◽  
High Frequency ◽  
Axial Flow ◽  
Multiple Scale ◽  
Amplitude Equations ◽  
Long Wavelength ◽  
First Order ◽  
Collapsible Tubes ◽  
Flow Through

Motivated by the problem of self-excited oscillations in fluid-filled collapsible tubes, we examine the flow structure and energy budget of flow through an elastic-walled tube. Specifically, we consider the case in which a background axial flow is perturbed by prescribed small-amplitude high-frequency long-wavelength oscillations of the tube wall, with a slowly growing or decaying amplitude. We use a multiple-scale analysis to show that, at leading order, we recover the constant-amplitude equations derived by Whittaker et al . (Whittaker et al. 2010 J. Fluid Mech. 648 , 83–121. ( doi:10.1017/S0022112009992904 )) with the effects of growth or decay entering only at first order. We also quantify the effects on the flow structure and energy budget. Finally, we discuss how our results are needed to understand and predict an instability that can lead to self-excited oscillations in collapsible-tube systems.

scholarly journals Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera - Noctuidae)

2010 ◽  
Vol 70 (3) ◽  
pp. 459-463 ◽  
Author(s):  
MJT. Assunção-Albuquerque ◽  
MC. Peso-Aguiar ◽  
FS. Albuquerque
Keyword(s):  
Larval Development ◽  
Energy Budget ◽  
Plant Biomass ◽  
Life Stage ◽  
Larval Growth ◽  
Dry Weight ◽  
Growth Efficiency ◽  
Economic Damage ◽  
Gross Growth Efficiency ◽  
Mocis Latipes

There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8% of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6%. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight) of Paspalum maritimum (Trin) in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

Annual gonadal and adrenal cycles in the Eastern Rosella, Platycerus eximius, (Psittaciformes : Platycercidae)

1976 ◽  
Vol 24 (4) ◽  
pp. 541 ◽  
Author(s):  
MJ Smith ◽  
JLG Brereton
Keyword(s):  
Social Rank ◽  
Gonadal Development ◽  
Early Summer ◽  
First Year ◽  
Adult Males ◽  
Cortical Cells ◽  
Physiological Phenomenon ◽  
One Year ◽  
Adrenal Cortical Cells ◽  
Gonadal Condition

Gonadal development in the eastern rosella was investigated in samples shot approximately monthly for one year near Armidale, N.S.W. In the testes of males of all ages and social rank, spermatogenesis begins in September, and by December the testis tubules of all males are filled with sperm. The histological stages of spermatogenesis are described. The Leydig cells of the testis are smaller in autumn, when the testes are regressing, than in early summer, when the testes are maximally developed. Between first-year and adult males, no differences could be discerned in the rate nor degree of development of testis tubules and intertubular tissue, but the weight of first-year birds' testes at full spermatogenesis was less than that of adults. In at least some first-year females the ovaries develop and eggs are released. Adrenal glands of adult males are smaller than those of females and first-year males. The adrenal cortical cells of all birds, male and female, are larger during the breeding season than during the subsequent moulting period. The similarity of gonadal condition between first-year birds and adults, together with the small differences in adrenals, leads to the conclusion that the failure of first-year birds to breed is a behavioural rather than physiological phenomenon.

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