Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Gas exchange characteristics and nitrogen relations of two Mediterranean root hemiparasites:Bartsia trixago andParentucellia viscosa (1993)
    Springer
    Oecologia 95 (1993), S. 145-151 
    Details
    ISSN: 1432-1939
    Schlagwort(e): Photosynthesis ; Nitrogen ; Parasitic angiosperm ; Gas exchange ; Leaf conductance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plant height, light-saturated rates of photosynthesis (A max) and foliar nitrogen concentration (N 1) were measured forBartsia trixago under field conditions in Mallorca. All three variables were postively correlated, and were also positively related to the abundance of nitrogen-fixing legumes in the associated vegetation (putative host species).A max forB. trixago ranged from 7.7 to 18.8 μmol m-2 s-1; similar rates were measured for a second hemiparasiteParentucellia viscosa, and both species were within the range of rates measured for six putative hosts (10.6–19.2 μmol m-2 s-1). Fertilization of unattachedB. trixago plants with inorganic nitrogen (ammonium nitrate) elicited neither the growth nor the photosynthetic responses observed in plants considered to be parasitic on legumes and in receipt of an enriched organic nitrogen supply. Both hemiparasites had high diurnal leaf conductances (g s) (469–2291 mmol m-2 s-1) and were at the upper end of the range of those measured in putative hosts (409–879 mmol m-2 s-1). In contrast with the latter, high nocturnal rates ofg s were also recorded for the two hemiparasites (517–1862 mmol m-2 s-1). There was no clear relationship between eitherA max orN 1 and eitherg s, transpiration (E) or water use efficiency (A max/E) inB. trixago plants. The economics of water loss appear to be independent of both the supply of nitrogen from the host and autotrophic carbon fixation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00649518
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    The design and performance of a new box corer for collecting undisturbed samples of soft subaquatic sediments (1995)
    Springer
    Journal of paleolimnology 14 (1995), S. 101-111 
    Details
    ISSN: 1573-0417
    Schlagwort(e): box corer ; Lake Baikal ; 210Pb sediment dating
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract The ‘Baikal’ sediment box corer represents an innovation in design of the closing mechanism and involves a single, thin, and flexible stainless steel blade rather than closing jaws. With this light-weight box corer only a relatively small cross-sectional area is offered to the sediment, allowing easier penetration. The closure blade is propelled smoothly across the base of the box in a downwardly convex path by a set of constant force springs. Depending on choice of blade-release mechanisms, the corer can either be triggered immediately as the support cable slackens, after a delay of a few seconds, or immediately upon retrieval. The box corer has been used successfully to sample poorly consolidated sediments in freshwater lakes over a depth range of 8 to 1624 m. Cores of deep-water surficial sediment from Lake Baikal were tested for representativity and replicability by profiling natural and artificial radioisotopes and lithostratigraphic features.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00735476
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Climate change in Lake Baikal: diatom evidence in an area of continuous sedimentation (2000)
    Springer
    International journal of earth sciences 89 (2000), S. 251-259 
    Details
    ISSN: 1437-3262
    Schlagwort(e): Key words Climate change ; Diatoms ; Turbidites ; Palaeolimnology ; Lake Baikal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract The presence of inhomogeneous sedimentation is acknowledged as being an important problem in palaeolimnological studies. Sediment records can be disturbed by erosional and redepositional events, which redeposit microfossils within a basin and may then lead to misinterpretations of fossil diatom assemblages. This study uses a combination of sedimentological tools, magnetic susceptibility measurements and high-resolution diatom analysis to show that a sediment core, BAIK80, taken in 345 m water depth from a shoulder region in the North Basin of Lake Baikal, is free of disturbances. Our results confirm that the sediment record is consistent and continuous for the uppermost sediment. Consequently, the fossil diatom data can be used to establish a continuous record of past climate variability over approximately the past 1300 years. Distinct changes occur in downcore abundances of endemic taxa Aulacoseira baicalensis and Cyclotella minuta, and principal components analysis (PCA) indicates a gradual transformation of taxa over the past 1300 years. These changes are likely to be related to climate, although definite links still have to be established.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s005319900063
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...