Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The relative significance of bacteria, meio- and macrofauna on an exposed sandy beach (1982)
    Springer
    Marine biology 66 (1982), S. 295-300 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A survey of the intertidal biota of a sandy beach on the west coast of South Africa has shown standing stocks of macrofauna, meiofauna and bacteria of 241.23, 200.17 and 663.07 g dry wt m-1 of shoreline respectively, an approximate biomass ratio of 1:1:3. The distribution of the macrofauna was the reverse of the usual pattern, with highest biomass occurring at the level of the current driftline. This appears to be related directly to the ready availability of food in the form of drift algae. Peak meiofaunal numbers were also found below the driftline and it is proposed that meiofaunal distribution is governed by dissolved organic matter (DOM) levels in the interstitial environment. Bacteria were abundant up to 1.2 m below the sediment surface, with the highest concentrations occurring at low tidal levels. The significance of the various biotic components in the energetics of the sandy intertidal is discussed. Turnover estimates suggest that bacteria may account for about 87% of annual production, with meiofauna and macrofauna making up 10 and 3% respectively. Despite this overwhelming importance of bacteria, the macro-and meiofauna probably play a vital role in making small organic particles available to bacteria for mineralization and in optimising conditions for microbial growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00397035
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Some relationships between size, food availability and energy balance in the ribbed musselAulacomya ater (1979)
    Springer
    Marine biology 51 (1979), S. 141-149 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of body size and suspension density on filtration rates, assimilation efficiencies and respiration rates in the ribbed musselAulacomya ater (Molina) have been determined by means of short-term laboratory experiments. Filtration rates accelerate rapidly in response to increasing algal concentration up to approximately 10×106 cellsDunaliella primolecta l-1, beyond which a plateau is approached. Percentage increments are greatest in small individuals. Assimilation efficiencies are independent of body size, but decline rapidly with increasing ration to approach zero above 32×106 cells l-1. Increases in respiration rate accompany increments in filtration rate in all but the smallest size class tested. Filtration, assimilation efficiency and respiration measurements are used to calculate ingestion rations, assimilation rations and scope for growth for mussels of different sizes over a range of algal concentrations. Scope for growth, expressed as percentage change in body energy per day, is a declining function of body size, but larger individuals achieve their maximum growth rates at lower ration levels than smaller ones. Growth efficiency is independent of body size, and is maximal at 5×106 cells l-1, where 29 to 43% of ingested ration is converted into body energy. The applicability of these experimental results to natural ecosystems is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00555193
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Energy expended on growth and gonad output in the ribbed musselAulacomya ater (1979)
    Springer
    Marine biology 53 (1979), S. 217-222 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Length/weight relationships have been computed for shell, flesh and byssus ofAulacomya ater (Molina) and energy values used to convert the weights to energy equivalents. Shell accounts for some 26% of total body energy, while the contribution of the byssus declines from 15 to 8% during growth. Observations of juvenile growth rates have been used to generate a Gompertz growth equation which predicts attainment of maximum length (90 mm) after 11 years. Reproductive condition has been assessed by monitoring seasonal fluctuations in the flesh weight of standard-sized individuals, calculated from monthly length/weight regressions. There appear to be three spawnings, of variable date and intensity, each year. From the above data, annual energy expenditure on growth and gonad output has been calculated for individuals of various sizes. The ratio of total production to biomass $$(P:\bar B)$$ is a declining clining function of shell length, dropping from 29.5 at 5 mm to 0.8 at 85 mm. The proportion of total production expended on gamete output increases steadily from 25% at attainment of maturity (15 mm) to 81% at 85 mm length. The considerable effects of changing size composition on the amount and type of production in natural populations are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00952429
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A comparison of macrofaunal and meiofaunal distribution and standing stock across a rocky shore, with an estimate of their productivities (1986)
    Springer
    Marine biology 93 (1986), S. 181-188 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In 1984 and 1985 algal, macrofaunal and meiofaunal standing stocks were estimated on a exposed rocky shore along the west coast of False Bay, South Africa, using comparable, area-based sampling techniques. The shore supported a rich growth of algae, particularly in summer, when a maximum standing crop of 403 g m-2 was recorded in the low shore. In winter, the largest component of macrofaunal biomass comprised the filter-feeding barnacle Tetraclita serrata, which attained 75 g m-2 in the middle balanoid; but as a result of late recruitment and high mortality of this species, the summer shore was dominated by herbivorous gastropods, particularly Patella cochlear, which attained a maximum biomass of 66 g m-2 on the low shore. Meiofaunal numbers and biomass were closely correlated to the distribution of algal turfs and associated trapped sediments. Numerically, the most important components of the meiofauna were nematodes and copepods, while the biomass was more evenly shared among foraminifera, minute gastropods, copepods and insect larvae. Numbers and biomass peaked in the lower balanoid during winter (1.9×106 individuals, or 8.5 g m-2). Macrofauna:meiofauna numbers and biomass ratios are presented for each zone and the distribution patterns discussed in relation to the conditons in each. Numerically, meiofauna exceed macrofauna by an overall ratio of 1:391, with values ranging from 1:556 in the lower balanoid to 1:18 in the Littorina zone. Macrofaunal biomass exceeds that of meiofauna in all zones by an overall ratio of 10:1, but values range from 2.1:1 in the upper balanoid to 48:1 in the middle balanoid. By incorporating turnover ratios extrapolated from the literature, mean annual productivity ratios have been calculated. These indicate that macrofauna account for 75% of total secondary production and meiofauna for 25%. Failure to incorporate meiofauna in analyses of energy flow on rocky shore ecosystems would thus lead to considerable errors. The possible trophic role of meiofauna in such systems is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508255
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Growth of pseudomorphic insulating HoF3 layers on Si(111) (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 1858-1860 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the successful growth of pseudomorphic, trigonal structured HoF3 insulating layers, stable at room temperature, on the Si(111) surface. Normally the tysonite structure is only stable at temperatures above 1070 °C [R. E. Thoma and G. D. Brunton, Sov. Phys. Crystallogr. 18, 473 (1966)]. A phase transition to the lower-temperature orthorhombic structure is observed for a thickness of around 12 A(ring), consistent with the relaxation of elastic strain in the insulating layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349506
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Dynamic vapor pressure measurements of the dimethyl zinc.triethylamine adduct using an ultrasonic monitor (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 1294-1296 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The 1:1 adduct of dimethyl zinc with triethylamine is an attractive precursor for the growth, using metal organic vapor phase epitaxy (MOVPE), of zinc based II-VI compounds due to its high purity and suppression of unwanted pre-reactions. A key parameter in MOVPE is the vapor pressure of the precursors which needs to be known in order to control the correct concentrations of organometallics entering the reactor. The literature on the vapor pressure of this precursor has been based on static measurements and has been inconsistent with the observed growth rates for ZnTe and ZnSe. An Epison ultrasonic monitor has been used to measure the concentrations under dynamic conditions and predict saturated vapor pressure (log10p=9.80–2596/T) which agree closely with the growth rate measurements but are up to a factor of 10 smaller than the static measurements. The reasons for these discrepancies are discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.115957
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Book reviews (1989)
    Springer
    World journal of surgery 13 (1989), S. 824-827 
    Details
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01658450
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Effect of topsoil storage on microbial activity, primary production and decomposition potential (1984)
    Springer
    Plant and soil 82 (1984), S. 41-50 
    Details
    ISSN: 1573-5036
    Keywords: Prairie grassland ; Microbial respiration ; Microbial biomass ; Fall rye ; Decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of disturbing (cultivating) and stockpiling prairie grassland topsoil on microbial activity, microbial biomass C, plant production and decomposition potentials were studied by measuring CO2 efflux from unamended and glucose amended soil in the laboratory and by conducting a pot and litter bag study in the greenhouse. Stockpiling appeared to have very little effect on soil respiratory activity, but did reduce the microbial biomass C levels. Throughout the 3 year study the microbial biomass C in the surface soil of the stockpile was less than that in the undisturbed soil, while the biomass C in soil at the bottom of the stockpile was at no time significantly different from that in the undisturbed soil. The reduction in microbial biomass C in the surface soil immediately after stockpiling was attributed to a decrease in the soil organic C levels caused by a slight dilution of the topsoil with subsurface mineral soil, and the exposure of the stockpile surface to extreme environmental conditions. Soils from all depths of the stockpile responded more slowly to the addition of glucose than soil from the undisturbed and cultivated treatments even when no differences in biomass were detected between the undisturbed and stockpiled soils. It is postulated that the rapidity with which the soil microbial biomass responds to glucose additions may be a sensitive indicator of stress on the soil biological components. The reduction in biomass after storage for 1 year had no adverse effects on the decomposition or primary production potential of the stored soil. Rather, shoot production by fall rye was stimulated in the stored topsoil, presumably a result of better N nutrition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02220768
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Topsoil storage effects on primary production and rates of vesicular-arbuscular mycorrhizal development inAgropyron trachycaulum (1984)
    Springer
    Plant and soil 82 (1984), S. 51-60 
    Details
    ISSN: 1573-5036
    Keywords: Slender wheatgrass ; Topsoil stockpiling ; VAM ; Decay rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A greenhouse study was conducted to determine the effects of stockpiling prairie grassland topsoil for 3 years on mycorrhizal development and root and shoot production of slender wheatgrass. The vesicular-arbuscular mycorrhizal (VAM) fungi involved in the symbiosis were also assessed as was the decomposition potential of the soil. During the first week of growth, VAM development in grasses grown in the stockpiled soil lagged behind that observed for grasses in the undisturbed soil. However, by 3 weeks, the mycorrhizal infection in plants in the stockpiled soil had reached levels similar to that in plants in the undisturbed soil. The dominant species of VAM fungi involved in the symbiosis at 8 weeks after planting shifted fromGlomus fasciculatum in the undisturbed soil toG. mosseae in the stockpiled soil. The delay in initial VAM infection and shift in VAM fungal species did not significantly affect plant productivity which was greatest in the stockpiled soil. The greater shoot production exhibited by grasses in the stockpiled soil was attributed to higher levels of NO3-N in the stockpiled than undisturbed soil. The potential of the soil to decay dead slender wheatgrass roots was not altered by stockpiling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02220769
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The ecology of kelp bed communities in the Benguela upwelling system (1977)
    Springer
    Helgoland marine research 30 (1977), S. 495-518 
    Details
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cool nutrient rich waters combined with a rocky coastline extending infratidally make the west coast of South Africa well suited to growth of kelp species. The kelp bed community is compared with the main kelp beds studied elsewhere (Nova Scotia, W. Europe, California). All these areas have cool, nutrient-rich water but the Benguela region differs in that large swells prevail. This paper deals with the determination of faunal and algal boundaries in these kelp beds (composed mainly ofEcklonia maxima andLaminaria pallida), as well as their biomass, in order to build a descriptive model of the food web. The main components of a site representative of the variable kelp beds on the west coast of the Cape Peninsula (Oudekraal) have been identified and quantified in terms of ash-free dry weight and Joules. The study covered an area from the rocky intertidal zone to the rock/sand interface found at a depth of 20 m. The site was divided into different areas (offshore, intermediate, inshore), and these were subdivided into depth zones of 4 m to show up any differences with depth. Different sampling techniques using SCUBA were combined to cover a wide range of organisms in the survey. Horizontal and vertical surfaces were differentiated. Kelp holdfasts were removed as a sampling unit for the infauna study. The distribution data of the organisms, other than kelp, were studied by means of multivariate methods which confirmed the division into inshore, mediate and offshore associations. Differences in faunal and floral composition could be detected between horizontal and vertical surfaces. Kelp biomass data showed high average standing crop in the inshore and mediate locality compared to the low offshore values. Maximum standing crop values, however, were not reduced. Mechanisms regulating the kelp bed structure are discussed. In the inshore and intermediate areas, algal biomass is much higher than animal biomass. A fact emerging from the data is that there is relatively little biomass of grazers; the major primary consumers are filter feeders. Problems of turnover rates are mentioned and an energy flow diagram for the area is proposed and its validity discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02207857
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...