bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal Dynamics of Planktonic Community Metabolism in Newly Constructed Tropical Ponds in a Swampy Area
Authors: Radheyshyam  , Naik D. R. 
Published: February 2007

AbstractStudies on community metabolism in newly constructed ponds on a swampy area were made over a period of twenty‐four months from November, 1981 to October, 1983. The fluctuations in the gross and net primary productions, photosynthetic efficiency and assimilation efficiency are discussed. The productivity of ponds was apparently influenced by the physico‐chemical and biological environment of the water. pH, secchi disc transparency, phosphate and nitrate‐N were negatively correlated with gross primary productivity, while temperature, conductivity, total alkalinity and ammonium‐N showed positive correlation. The phytoplankton also exhibited positive correlation with primary production. The P/R ratio ranged between 1.79 and 2.91, indicating a high degree of self maintenance of the system. The solar energy conversion efficiency through photosynthesis ranged between 0.17 % and 1.08 % in the first year and 0.09 % and 0.05 % in the second year. Annual average assimilation efficiency ranged between 37.32 % and 56.58 %.
A Study on the Impact of Urban and Industrial Development in the Linggi River Basin, Malaysia. 2. Chemical Environment
Authors: Khan I. S. A. Nather 
Published: February 2007

AbstractAn investigation of the chemical environment of the Linggi River Basin was carried out at 15 main and 27 supplementary stations between January 1983 and January 1984. Spatial and temporal changes in pH, specific conductivity, alkalinity, chloride, ammonia‐nitrogen, nitrite‐nitrogen, nitrate‐nitrogen, orthophosphate, dissolved oxygen, BOD, and diurnal variations were studied in relation to influence of various kinds of pollutants. The chemical composition of natural water analysed at a few undisturbed forest stream stations in the basin can be considered very good. A drastic change in river water quality was noticed in downstream polluted stations. The pH in the basin varied from 4.05 to 10.5 units, conductivity from 23.0–1,500 umhos/cm, alkalinity from 6.0–1,388 mg/l, chloride from 0.9–160.9 mg/l, orthophosphate from 0.5–5.21 mg/l, ammonia‐N from 0.001–53.75 mg/l, nitrite‐N from 0.0–8.2 mg/l, nitrate‐N from 0.03–6.77 mg/l and BOD3, from 0.32–384.0 mg/l and COD from 0.02 to 79.2 unit. Among all the rivers, very high values were recorded at Kundor, Simin and Linggi (sensu stricto).
Population Dynamics of Crustacean Zooplankton in a Mesotrophic Lake, with Emphasis on Boeckella hamata BREHM (Copepoda: Calanoida)
Authors: Burns Carolyn W. 
Published: February 2007

AbstractThe crustacean zooplankton in Lake Mahinerangi, a polymictic, mesotrophic reservoir, were studied for 19 months. The cladocerans, Bosmina meridionalis and Ceriodaphnia dubia, had unimodal patterns of abundance with peak densities in summer; cyclopoids had a single peak of maximum abundance in autumn and Daphnia carinata showed a bimodal pattern with peak densities in early summer and early winter. The strong seasonality in abundance of zooplankton in Lake Mahinerangi distinguishes this lake from other temperate lakes in New Zealand and may reflect its cool winter temperatures (< 5 °C for 2 months). A calanoid, Boeckella hamata, bred throughout the year and was the dominant species numerically. Instar analysis indicated that there were at least three, and possibly four, generations per year. Instantaneous birth and death rates were low with annual mean values (0.036 and 0.057, respectively) that were 2‐3.5 times less than those recorded in a population of the same species in Lake Pounui, but within the range of those recorded in calanoid populations elsewhere in New Zealand. The Boeckella population in Lake Mahinerangi appears to be controlled largely by temperature, parasitism and food, with predation having no, or a negligible, effect.
The Concept of Seasonal Succession Theory Applied to Phytoplankton Through the Coupling Use of Diversity Index and Rank‐Frequencies Diagrams in a Eutrophic Ecosystem
Authors: Aleya Lotfi , Devaux Jean 
Published: February 2007

AbstractSeasonal succession of phytoplankton was studied in a eutrophic lake (Lake Aydat, Massif Central, France), from March to November 1985.An attempt is made to check the succession stages of the concept of ecological succession theory using either the H‐diversity index of SHANNON and WEAVER or the FRONTIER'S rank‐frequencies diagrams. A description of a stage 3 community was only possible through the use of the latter diagrams.
Development, Reproduction and Growth Pattern of two Coexisting, Pond Dwelling Cladocerans
Authors: Maier Gerhard 
Published: February 2007

AbstractLaboratory investigations on life history parameters of 2 coexisting cladocerans (Daphnia obtusa. Moina brachiata) from a nearly temporary pond in South Germany revealed that the species have different temperature tolerances and temperature optima. D. obtusa experienced the highest reproductive success at 15 and 20 °C and was able to survive and to reproduce at 2 °C but died at 30 °C. The reproductive success of M. brachiata was highest at 25 and 30 °C and the species could not withstand temperatures <15 °C and ≥35 °C. At temperatures between approximately 20 and 25 °C, where both cladocerans coexisted in nature, M. brachiata showed a faster population growth due to its approximately twofold higher egg production rates (10–12 eggs female−1 day−1 compared to approximately 5 eggs female−1 day−1 in D. obtusa) and its shorter juvenile development (3.3 and 2.4 days compared to 6.3 and 5.3 days in D. obtusa); M. brachiata needs generally only 3 molts to reach maturity while D. obtusa requires 5–6 molts.
Dispersions‐, Abundanz‐ und Dominanzdaten von koexistierenden Hydroporus‐Imagines (Coleoptera; Dytiscidae) aus sekundären Moorgewässern
Authors: Behr Hauke 
Published: February 2007

AbstractThe population dynamic of coexisting Hydroporus‐species (adults) living in 2 secondary bog pools is described. Both pools are charakterized by a typical community structure, persisting over a period of 4 years. They also differ in physical and chemical properties. None of the 5 coexisting populations in a shaded pool is dispersed equally. Most individuals were kept in an area of 0–20 cm water depth. On an average 42–100 individuals/m2 were recorded from a pool lying in a secondary birch swamp (Betuletum pubescentis).
Unterschiede in Eibiologie und Habitatbindung zwischen Prosimulium tomosvaryi (Prosimuliini) und verschiedenen Simuliini (Diptera, Simuliidae)
Authors: Timm Tobias 
Published: February 2007

Differences in Egg‐biology and Habitat Binding between Prosimulium tomosvaryi (Prosimuliini) and Simuliini (Diptera, Simuliidae)Oviposition of the mountain black fly Prosimulium tomosvaryi (Enderlein, 1921) (tribe Prosimuliini) takes place in May in the „Niederbergisch‐Märkisches Hügelland”︁ (North Rhine‐Westphalia). The eggs aestivate until late November. They differ in morphology, egg‐layers and germ band‐formation from tribe Simuliini. The development is negatively correlated with temperature: the embryo develops slowly, but without a pause at low temperatures (<10°C), while high temperatures (>12°C) prevent development (temperature controlled dormancy). It is explained that distribution of Prosimulium species in Central Europe is limited by the potency of the terrestrial egg stage.
Seasonal and Spatial Distribution of Vitamin B12 in a Coastal Area of Eastern Mediterranean Sea
Authors: Moschopoulou N. , Ignatiades L. 
Published: February 2007

AbstractThe seasonal and spatial distribution of vitamin B12 was investigated in Eastern Mediterranean (Saronicos Gulf, Aegean Sea). Vitamin B12 concentration had an annual range 0.12–7.93 ng. 1−1 and an annual mean 1.88 ng. 1−1. The statistical analysis of data indicated significant seasonal and regional variations of vitamin B12 in this area and an inverse relationship of this vitamin with chl a. The results showed that the Eastern Mediterranean Sea contains less vitamin B12 than the Western Mediterranean Sea.
Addition to Water‐borne Fungal Spora of Western Ghat Streams, India
Authors: Sridhar K. R. , Kaveriappa K. M. 
Published: February 2007

AbstractConidial propagules encountered in foam samples of three lotic sources in Western Ghat forests of India are reported. Nine species can be assigned to known genera of water‐borne hyphomycetes. Five kinds of conidia could not be assigned to known genera. Some of the conidia resemble spore types reported from Africa, Thailand and Malaysia.
Thermal Regime and Stability of Jurumirim Reservoir (Paranapanema River, São Paulo, Brazil)
Authors: Henry Raoul 
Published: February 2007

AbstractThermal regime and stability in Jurumirim Reservoir (São Paulo, Brazil) were studied for a year. Isothermy and thermal stratification were observed from June to September and from October to March, respectively. The annual heat budget was 14.0 Kcal · cm−2 and average heat gain per day was 67.2 cal · cm−2 · day−1. Maximum stability and wind work reached 324.2 and 3,037.5 g · cm · cm−2, respectively. According to thermal structure and heat content, Jurumirim Reservoir was classified as a warm tropical monomictic lake.
The Seasonal Dynamics and Trophic Relations of the Plankton Components in Lake Peipsi (Peipus)
Authors: Nõges Tiina , Haberman Juta , Timm Malle , Nõges Peeter 
Published: February 2007

AbstractThe seasonal dynamics of the biomass and production of phyto‐, zoo‐ and bacterioplankton was investigated during the vegetation periods (from May to November) in 1985 and 1986 in the pelagial of the large eutrophic lake Peipsi (Estonia). The average values of productions per vegetation period for the investigation years were as follows: phytoplanktion − 203.5 gC · m−2; bacterioplankton − 37.9 gC · m−2; filter‐feeding zooplankton − 20.6 gC · m−2 and predatory zooplankton − 1.5 gC · m−2. The herbivorous zooplankton production constituted 10.1% of primary production. This ratio indicates a direct relationship between zoo‐ and phytoplankton in the food chain — filtrators are feeding mostly on living algae and the detrital food chain seems of little importance. The dominance of large forms (Melosira sp., Aphanothece saxicola), in the phytoplankton during the major part of the vegetation period is assumed to be a result of high grazing pressure on small algae. Zooplankton grazing was investigated in situ in a specially constructed twin bathometer. Experimental measurements revealed, that zooplanktion presence in the experimental vessel actually stimulated the phytoplankton growth in many cases — the negative grazing values have been registered. That could be caused by the stimulation effect of nutrients (N, P), excreted by the concentrated zooplankton in the grazing chamber, which led to an increase of the nongrazed phytoplankton production. Bacteria have satisfied the zooplankton food requirements on average by 11%. Grazing on bacteria increased, when grazing on phytoplankton was somehow disturbed.
Long‐Term Temporal and Spatial Fluctuations of Soft Bottom Infaunal Invertebrates Associated with an Ocean Outfall from the San Pedro Shelf, California
Authors: Maurer Don , Robertson George , Gerlinger Thomas 
Published: February 2007

AbstractTemporal (annual) and spatial fluctuations of soft‐bottom invertebrates from 1977 to 1988 were reviewed and analyzed from an ocean outfall area on the San Pedro Shelf, California. Several dominant species which occurred throughout the monitoring period provide continuity between early sampling efforts and recent ones. Annual fluctuations in the mean number of species, abundance, diversity and biomass were generally conservative compared to spatial fluctuations. Temporal changes of note include a marked reduction in abundance and biomass between 1981 and 1984 and another decline in biomass in 1988. The former was associated with conditions of the 1982–1983 El Niño, and the latter with a shift in population dominance from a bivalve to a polychaete.Mean abundance and biomass were enhanced by the outfall without a significant reduction in number of species. The response of the biota to the outfall extended further upcoast (northwest) than downcoast.Several hypotheses were posed and briefly examined. These include the effects of total suspended solids generated from the outfall, and the role of the “Three Little Pigs” (bivalve‐Parvilucina tenuisculpta CARPENTER, ostracod‐Euphilomedes carcharodonta (SMITH), polychaete‐Capitella capitata (FABRICIUS)) in influencing benthic community structure. Finally, measures of infauna from the San Pedro Shelf were, except for abundance, very similar to those reported from other California shelf areas. Through time and space the outfall has had limited negative effect on infaunal community structure.
Time Compatibility of Water Chemical Lake Variables
Authors: Håkanson Lars 
Published: February 2007

AbstractThis paper summarizes results from extensive field work in 95 Swedish lakes. The focus is on methodological aspects of importance when establishing the time compatibility of traditional water variables (monthly data on pH, Secchi depth, temperature, alkalinity, total‐P, conductivity, Fe, Ca, hardness and colour from 4 years, 1986 to 1989). From most textbooks in limnology, it is evident that there exist patterns, in terms of how the concentrations and the variability of the concentrations of these standard variables vary in lakes. Then it would be interesting to see if there exists patterns also for the time compatibility between different lake variables and different variants of the same variable, i.e., mean values from different periods. This issue is discussed in a systematic way in this paper with statistical methods. These results are of importance in ecosystem analyses, monitoring and modelling. These parameters generally vary in a lake, both temporally and areally, the focus here is on such variations and how to express lake‐typical, time compatible values for longer periods of time. Selected results: High correlations (r2‐values) exist between (1) mean annual pH and all the variants of alkalinity and lake colour for different periods of time. (2) between mean (3 year) total‐P and most of the variants of total‐P, especially those from the winter period (months 10 to 12; r2 ≈ 0.95), but not for the variants from the spring and the summer periods, when the variability is great for total‐P, (3) between mean (3 year) lake colour and most of the variants of Fe and pH, especially those from the first half of the year for pH and those from the second half of the year for Fe. Quite high r2‐values, about 0.5, exist between colour and different variants from the winter period for total‐P and Secchi depth.
Long‐Term Trends in the Nutrient Input and In‐Lake Concentrations of a Drinking Water Reservoir in a Dense Populated Catchment Area (Erzgebirge, Germany)
Authors: Horn W. , Horn H. , Paul L. 
Published: February 2007

AbstractThe concentrations of soluble reactive and total phosphate, silicate, and nitrate in the tributaries and in the watercolumn of the meso/eutrophic reservoir Saidenbach were investigated at weekly or fortnightly intervals. The results are presented as annual averages over 16 years (from 1975 till 1990) and show a gradual increase of the N‐ and P‐concentration in the inlets caused by an intensification of the agriculture in the drainage basin and high domestic sewage releases from the settlements having no waste water treatment. The silicate concentration of the inlets remained constant. Consequently, also a rise of the in‐lake concentrations of the two P‐fractions was observed. The nitrate concentration of the reservoir Saidenbach increased till 1978, but showed no significant trend over the whole investigation period. The drop of the in‐lake silicate concentration during the eighties has to be explained by diminished discharges and, most of all, a higher biological activity as a consequence of the increased P‐loading.Intra‐annual concentrations calculated as winter, spring, summer (epi‐ and hypolimnion) and autumn means show the distinct seasonal periodicity of the phosphorus and silicon cycles. Therefore, annual average in‐lake concentrations of these nutrients are not quite good measures reflecting changes of the trophic conditions, but rather the winter and early spring values are. No correlations were detected between the annual mean concentrations and the loads. On the other hand, no remarkable seasonal cycling of the nitrate concentrations could be observed and, in this case, a clear dependence exists between annual mean concentrations and loads.The results found for the tributaries of the meso/eutrophic reservoir Saidenbach were compared with those observed in the inlets of the neighbouring oligotrophic reservoir Neunzehnhain. Here the phosphorus concentrations remained almost constant during the time of investigation, but the nitrate concentrations increased too. This must be attributed to agriculture, air pollution and forest management.
Spring‐Summer Succession of Planktonic Rotifers in a South Andes Lake
Authors: Modenutti Beatriz E. 
Published: February 2007

AbstractThe dynamics of planktonic rotifer in Laguna Ezquerra (Rio Negro, Argentina) was studied from October 1988 to March 1989, in relation to food resources and cladoceran populations. During the spring and summer period, total rotifer density differed markedly. In spring rotifer populations remained at low density and an inverse relationship with cladoceran biomass was found. In contrast, in summer, the rotifer densities increased greatly and a positive relationship with cladoceran biomass was observed. Food resources decreased during mid January and this seemed to give rotifers a competitive advantage over cladocerans. Bosmina longirostris and Ceriodaphnia dubia were both present during the spring, but only Bosmina prevailed in summer. The composition of cladoceran assemblages together with food resources seem to be an important factor in rotifer dynamics.
Allochthonous Input of Coarse Particulate Organic Matter (CPOM) in a First to Fourth Order Austrian Forest Stream
Authors: Weigelhofer G. , Waringer J. A. 
Published: February 2007

AbstractThe allochthonous input of coarse particulate organic matter (CPOM) at the Mauerbach, a low order Austrian forest brook, was investigated from October 1990 to November 1991. Annual input rates ranged from 361.5 to 716.2 g dry weight m−2 for the direct input and 46.6 to 594.9 g m−1 for the lateral input. Input rates were influenced by the composition and density of the riparian vegetation and the bank inclination. The temporal distribution of the direct input showed an autumnal maximum (50–70% of the total), whereas for the lateral input an autumn (30–50%) and a spring (19%) peak were observed. Along the course of the stream, the proportion of the lateral input increased with decreasing stream width. Total annual input for the Mauerbach was 21.8 t CPOM, with 73.4% due to direct and 26.6% due to lateral input.
Polymorphism and Food Limitation in Three Daphnia carinata Populations
Authors: Chapman M. A. , Burns Carolyn W. 
Published: February 2007

AbstractThe annual cycles of Daphnia carinata in three fish‐free ponds in southern New Zealand (Quarry, Taieri and Raupo Ponds) are described. Although breeding was continuous, the populations were frequently dominated by distinct cohorts and there was a sexual phase in spring. Growth rates, particularly in Quarry Pond, were often slow, and clutch sizes generally small. Egg and neonate sizes changed seasonally, but changes were not closely related to clutch sizes and body lengths. In Taieri Pond and Raupo Pond some D. carinata grew to 6.14 mm and carried clutches of up to 154 eggs. The potentially high fecundity associated with large size makes D. carinata a good coloniser, but our studies showed that it also survives well in poor food conditions by growing slowly and producing only 1–2 eggs per clutch.D. carinata showed marked seasonal polymorphism in tailspine length and development of head crests. In winter, crests were absent and tailspines were short and varied little with body length. Crests were first apparent, and tailspines began to elongate, in early spring, before the first appearance of a notonectid, Anisops wakefieldi. By midsummer, tailspines had increased markedly with body length but the slope of the relationship declined in autumn. Laboratory trials showed that both tailspine length and crest development increased in the presence of Anisops. These increases may be due to water‐soluble factor(s) produced by Anisops.
Feeding Rate of Brachionus plicatilis O. F. Müller on Two Types of Food Depending on Ambient Temperature and Salinity
Authors: Lebedeva L. I. , Orlenko O. N. 
Published: February 2007

AbstractFeeding rates of Brachionus plicatilis were studied for two types of food — algae Monochrysis lutheri and baker's yeast Saccharomyces cerevisae. The main regularities of changes in filtration rate and ration were studied in small culture volumes (1 ml) for adult amictic females depending on food concentration (1, 2, 4, 8 and 16 · 106 cells · ml−1), ambient temperature (16 and 26 °C), and salinity (5, 10, 15, 20, 25 and 30 ppt). B. plicatilis ration did not depend on the salinity, but was largely determined by temperature and food concentration. It was found that at 16 and 26 °C the dependence of the ingestion rate (ration) on food concentration differed greatly. A hypothesis was suggested to explain this phenomenon. A critical concentration of both types of food at which the increase in the rotifer ration ceased is 4 · 106 cells · ml−1. This is the minimum “background” food concentration for B. plicatilis mass cultivation.The average rations measured at the concentration of M. lutheri and S. cerevisae of 4 · 106 cells · ml−1 where 1.3 ± 0.1 and 4.8 ± 1.3 μg dry weight. · ind−1 · day−1 at 26 °C and 0.54 ± 0.1 and 1.9 μg d. w. · ind−1 · day−1 at 16 °C, respectively. The rations obtained in the laboratory were corrected for the conditions of rotifer commercial production in the open field in summer time. The correct values were 0.86 and 0.72 μg d. w. · ind−1 · day−1 for algae and yeast, respectively.
A Quantitative Photographic Survey of ‘Spoke‐Burrow’ Type Lebensspuren on the Cape Verde Abyssal Plain
Authors: Bett Brian J. , Rice Anthony L. , Thurston Michael H. 
Published: February 2007

AbstractA photographic survey of the seafloor was conducted during RRS Discovery cruise 204 in September/October 1993 at the oligotrophic site of the French EUMELI programme at c. 21° N: 31° W (4650 m) on the Cape Verde Abyssal Plain. Two systems were used, a wide angle system (WASP) obtaining usable photographs covering 10 to 30m2, and an epibenthic sledge mounted system obtaining photographs of about 2 m2.A total of more than 3000 usable frames were obtained, covering about 64000 m2 of seafloor. The photographs indicated an epibenthic invertebrate megafaunal density of 5.2 hectare−1 and a demersal fish density of 1.8 hectare −1. In contrast, the photographs were dominated by lebensspuren, particularly of the ‘spoke‐burrow’ type usually attributed to echiurans. Spoke‐burrow density, where related burrows and other features such as sediment mounds are considered unitary, is estimated at 871 hectare −1. We describe and quantify the five principal types of spoke burrow encountered in this study and, on the basis of these observations and some morphometric studies of the lebensspuren, discuss the possible behaviour of their producers.We have no direct knowledge of the production rate of, or longevity of, lebensspuren in the study area. However, based on a number of assumptions and limited data from other areas we suggest that trace producer (mainly echiurans) density is on the order of tens of individuals per hectare. These trace producers probably greatly outnumber the rest of the invertebrate megabenthos, and we can only guess at the role this potential large population of hidden benthos might have in the overall structure and function of the deep‐sea floor ecosystem.