Primary production and life history of Carex lacustris

1974 ◽  
Vol 52 (1) ◽  
pp. 117-123 ◽  
Author(s):  
John M. Bernard ◽  
James G. Macdonald Jr.
Keyword(s):  
Life History ◽  
Primary Production ◽  
Standing Crop ◽  
Daily Production ◽  
A Value ◽  
Aboveground Production ◽  
History Of ◽  
The Difference ◽  
Carex Lacustris ◽  
Very High

Seasonal changes in aboveground and belowground standing crop and primary production in a Carex lacustris wetland were determined and related to the basic life history of this species. There was a seasonal minimum of 180 g/m2 green material aboveground frozen in the ice in winter and a maximum of 1037 g/m2 in summer (early August). Seasonal aboveground production based on quadrat data and based on the difference between maximum and minimum standing crop is estimated to be 857 g/m2 per year, maximum daily production 15 g/m2 per day. A second estimate, also based on quadrat data but taking into account the very high shoot mortality during the growing season, was determined. Seasonal aboveground production then is 1580 g/m2 per year, maximum daily production is 20.3 g/m2 per day. Belowground standing crop was 387 g/m2 in winter but then declined to an average summer low of 226 g/m2. Belowground standing crop increased during autumn and, by October 7, a value equal to the previous winter's value was reached. Shoots of this species live for 1 year or less, emerging in autumn, overwintering, and then dying sometime during the next summer.

Nutrient cycling in a Carex lacustris wetland

1977 ◽  
Vol 55 (6) ◽  
pp. 630-638 ◽  
Author(s):  
John M. Bernard ◽  
Betsy A. Solsky
Keyword(s):  
Life History ◽  
Nutrient Cycling ◽  
Seasonal Changes ◽  
Early Growth ◽  
Total Production ◽  
Belowground Production ◽  
Aboveground Production ◽  
History Of ◽  
Phosphorus And Potassium ◽  
Carex Lacustris

Seasonal changes in aboveground and belowground life history of Carex lacustris were determined and used to study primary production and nutrient cycling in the ecosystem. Seasonal aboveground production was estimated to be about 965 g/m2 per year, with a peak rate of 20.9 g/m2 per day reached in late July. Belowground production was estimated to be 208 g/m2 per year for a total production estimate of 1173 g/m2 per year.Nitrogen, phosphorus, and potassium begin the season with high percentage concentrations in green overwintering shoots but the percentages decline to only about one-third of the original at death in December. Early growth in spring is characterized by a redistribution of these nutrients in the shoots, some translocation from belowground tissues, and uptake from the soil. Calciumand magnesium do not show any important translocation patterns during the year.The yearly budget of uptake and loss of nutrients during a year is estimated to be 15.9 g/m2 nitrogen, 1.9 g/m2 phosphorus, 16.6 g/m2 potassium, 2.9 g/m2 calcium, and 1.5 g/m2 magnesium.

scholarly journals The Difference Language Makes: The Life-History of Nahuatl in Two Mexican Families

2016 ◽  
Vol 26 (1) ◽  
pp. 81-97 ◽  
Author(s):  
Magnus Pharao Hansen
Keyword(s):  
Life History ◽  
Mexican Families ◽  
History Of ◽  
The Difference

scholarly journals Variations between two 24-hour urine collections in patients

2013 ◽  
Vol 6 (1) ◽  
pp. 30 ◽  
Author(s):  
Madhur Nayan ◽  
Mohamed A. Elkoushy ◽  
Sero Andonian
Keyword(s):  
Clinical Decision Making ◽  
Clinical Decision ◽  
Metabolic Evaluation ◽  
Normal Limits ◽  
A Value ◽  
Two Samples ◽  
History Of ◽  
The Absolute ◽  
The Difference ◽  
Urinary Parameters

Introduction: The current Canadian Urological Association (CUA)guideline recommends two 24-hour urine collections in the metabolic evaluation for patients with urolithiasis. The aim of the present study was to compare two consecutive 24-hour urine collections in patients with a history of urolithiasis presenting to a tertiary stone clinic.Methods: We retrospectively reviewed 188 patients who had two24-hour collections upon presentation between January 2010 and December 2010. Samples were collected on consecutive days and examined for the following 11 urinary parameters: volume, creatinine, sodium, calcium, uric acid, citrate, oxalate, potassium, phosphorous, magnesium and urea nitrogen. For each parameter, the absolute value of the difference between the two samples rather than the direct difference was compared with zero. Similarly, the percent difference between samples was calculated for each parameter.Results: The means of the absolute differences between the twosamples were significantly different for all 11 urinary parameters(p < 0.0001). The percent differences for all urinary parametersranged from 20.5% to 34.2%. Furthermore, 17.1% to 47.6% ofpatients had a change from a value within normal limits to anabnormal value, or vice-versa. Significance was maintained when patients with incomplete or over-collections were excluded.Conclusions: Significant variations among the two 24-hour urinecollections were observed in all of the 11 urinary parameters analyzed. This variation may change clinical decision-making in up to 47.6% of patients if only a single 24-hour urine collection is obtained. The present study supports the CUA guideline of performing two 24-hour urine collections.

The life history of shoots of Carex lacustris

1975 ◽  
Vol 53 (3) ◽  
pp. 256-260 ◽  
Author(s):  
John M. Bernard
Keyword(s):  
Life History ◽  
Water Level ◽  
Early Spring ◽  
Basal Diameter ◽  
Late Autumn ◽  
History Of ◽  
Carex Lacustris

Most shoots of Carex lacustris live for about 12–14 months, emerging in autumn, overwintering as shoots of up to 50 cm in length, and maturing during the next summer. Others emerge in early spring but both groups die in late autumn. A third class emerges in late July or August, grow to be over 50 cm in length, and die in late autumn, living only 2 or 3 months.Flower initials in this species begin growth in the September–October period and overwinter while about 1.0 cm in length. The shoots that develop inflorescences are in general longer, heavier, and have a greater basal diameter than those shoots which do not flower. More shoots flower if the water level in the marsh was high the previous year.

scholarly journals Estimation of Fitness of Normal and Stylopized Paddy Pest, White Leafhopper Cofana spectra (Distant) (Hemiptera: Cicadellidae), in West Bengal, India through Correlation of Life History Traits

2014 ◽  
Vol 6 ◽  
pp. IJIS.S13029
Author(s):  
Sangita Mitra ◽  
Rupa Harsha ◽  
Niladri Hazra ◽  
Abhijit Mazumdar
Keyword(s):  
Life History ◽  
Life History Traits ◽  
West Bengal ◽  
Principal Component ◽  
Relative Importance ◽  
Regression Analyses ◽  
Morphometric Measurements ◽  
History Of ◽  
The Difference ◽  
The Individual

The assessment of the morphological and reproductive features of white rice leafhopper Cofana spectra (Distant) was carried out using selected characters that bear importance in determining the fitness at the individual and population levels. Morphometric measurements of the individuals reared in the laboratory as normal and stylopized with the strepsipteran parasitoid, Halictophagus australensis Perkins, were recorded and analyzed. A t-test was performed to justify whether parasitization by H. australensis affected the traits. Correlations and regression analyses were carried out to deduce the difference in relative importance of the morphological features in the life history of C. spectra and their variation because of stylopization by H. australensis. A principal component analysis (PCA) was applied on the morphometric data to further substantiate the difference observed in the traits. In case of stylopized white leafhopper (WLH), fecundity was inhibited almost completely irrespective of seasons. The effect of stylopization on the life history traits of C. spectra has been noted that supports its possible use in biocontrol.

Annual production of Typha orientalis Presl. in inland Australia

1986 ◽  
Vol 37 (5) ◽  
pp. 659 ◽  
Author(s):  
J Roberts ◽  
GG Ganf
Keyword(s):  
Demographic Data ◽  
Plant Production ◽  
Carbon Substrate ◽  
Emergent Macrophytes ◽  
Continuous Growth ◽  
A Value ◽  
Whole Plant ◽  
Aboveground Production ◽  
Harvest Data ◽  
The Difference

The annual aboveground production of T. orientalis was estimated from harvest data by three techniques. The first calculated production as the difference between maximum and minimum standing crop and gave a value of 1175 g m-2. Demographic data showed this was an underestimate. The second estimate by Smalley's method of 3824 g m-2 was considered an overestimate since no account was taken of stand variability. The third estimate, 2334 g m-2, used data fitted by splined regression and was considered the most reliable since it accounted for stand variability, continuous growth, shoot mortality and the translocation of carbon substrate. Annual aboveground production of inland T. orientalis was greater than most estimates from temperate climates, and whole plant production, 4379 g m-2, greatly exceeded the suggested maximum of 3000 g m-2 for freshwater emergent macrophytes.

On the biology of Pandalus borealis Krøyer, with reference to a population off the Northumberland coast

1959 ◽  
Vol 38 (1) ◽  
pp. 189-220 ◽  
Author(s):  
J. A. Allen
Keyword(s):  
Life History ◽  
Deep Water ◽  
Deep Sea ◽  
Sex Reversal ◽  
High Latitudes ◽  
Southern Limit ◽  
Pandalus Borealis ◽  
A Value ◽  
History Of ◽  
Southern Norway

The deep sea prawn, Pandalus borealis Krayer, is fished extensively in Norwegian, Swedish and Greenland waters, some 4000 metric tons being caught annually, having a value of about £800,000. Its biology has been investigated by various workers in these countries. Comprehensive accounts have been given by Wollebaek (1903), Hjort & Ruud (1938), Rasmussen (1953)and Horsted & Smidt (1956). Despite this, relatively few populations have been sampled at regular intervals throughout a year. In high latitudes where much work has been carried out, ice, for varying lengths of time, prevents stocks from being sampled. Rasmussen (1942, 1949, 1953) has shown that the life history of P. borealis varies with locality in a range from southern Norway to Spitsbergen. When P. borealis was found in numbers in deep water off the Northumberland coast advantage was taken to investigate the biology of the species at the southern limit of its eastern Atlantic distribution and to compare the results with those of other workers. Knowledge of the biology of the prawn now covers the whole of its north-south distribution and some account of this is given. In addition, the study gives information on a population that has not been fished commercially and provides a more complete picture of sex reversal than has been obtained hitherto.

Above- and below-ground macrophyte production in Scirpus tidal marshes of the St. Lawrence estuary, Quebec

1988 ◽  
Vol 66 (5) ◽  
pp. 955-962 ◽  
Author(s):  
Jean-François Giroux ◽  
Jean Bédard
Keyword(s):  
Standing Crop ◽  
River Estuary ◽  
Dry Mass ◽  
Tidal Marshes ◽  
Lawrence Estuary ◽  
Aboveground Production ◽  
History Of ◽  
Below Ground ◽  
South Shore ◽  
St Lawrence Estuary

Above- and below-ground standing crops as well as primary production of several macrophytes were estimated in Scirpus marshes along the south shore of the St. Lawrence River estuary in Quebec. Aboveground standing crop was measured by clipping vegetation, while belowground standing crop was estimated by soil coring. Seasonal variation of live and dead standing crops was first determined for different plant species. The root:shoot mass ratio was then examined and related to the life history of each species. Total aboveground production varied from 74 to 627 g ash-free dry mass∙m−2∙year−1 among different plant communities, whereas belowground production was lower, with estimates varying between 38 and 244 g∙m−2∙year−1. Production was lower along the St. Lawrence estuary than in other types of marshes located farther south.

scholarly journals Notes on the Life History of Anaphia petiolata (Kröyer)

1916 ◽  
Vol 11 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Marie V. Lebour
Keyword(s):  
Life History ◽  
Life Histories ◽  
Early Summer ◽  
Present Form ◽  
Pale Yellow ◽  
Larval Stages ◽  
Bright Pink ◽  
History Of ◽  
The Difference ◽  
Fourth Pair

In the early summer of 1915 it was' noticed that many medusæ brought in with the tow-nettings contained larval Pycnogonids in the manubrium and at the junction of manubrium and stomach. The medusæ specially noticed to contain them were Obelia sp., Cosmetira pilosella, Turris pileata, Stomotoca dinema and Phialidium hemisphericum. By far the greater number were in Obelia, although many were in Phialidium hemisphericum and Cosmetira pilosella. They were extremely abundant in June, after that became scarcer, and finally disappeared by October. On examination they were seen to be larval stages of Anaphia petiolata (Kröyer), a Pycnogonid common in Plymouth Sound. The older larvæ sometimes were seen to cast their skins, so that the species could be easily recognised, although the fourth pair of walking legs were not fully developed. This is evidently the species described by Dogiel (1913) as Anoplodactylus pygmœus, the life history of which he traces from its first entry into the Obelia hydroid to the older stages when it is ready to leave its host. The form he refers to as Anoplodactylus petiolatus occurring in cysts in Coryne with Phoxichilidium femoratum must be some other species, as his figures prove clearly that it differs from A. pygmœus, and also the colour is totally different (a bright pink, while the present form is a pale yellow). Dogiel believes he has proved that Anoplodactylus petiolatus and A. pygmœus are different species from the difference in their life histories, and it is evident that he is dealing with two different species, but his A. petiolatus cannot be the same as our form, which is certainly identical with his A. pygmœus, and shows that Sars (1891) and Norman (1894) were right in regarding A. pygmœus as the young form of A. petiolatus (Kröyer).

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