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 contribution of rabbits (Oryctolagus cuniculus L.) to soil fertility in semi-arid Spain (2000)
    Springer
    Biology and fertility of soils 31 (2000), S. 379-384 
    Details
    ISSN: 1432-0789
    Keywords: Key words Bioassay ; Fertile islands ; Latrine ; Mediterranean ecosystem ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Degradation of land in vulnerable areas can be significantly reduced by the maintenance or establishment of plant cover and diversity. Animals can facilitate plant diversity by grazing, by dispersing seeds or by contributing, through excreta, to the heterogeneous distribution of nutrients in soil. We investigated the latter property by examining the effects of rabbit (Oryctolagus cuniculus L.) dung deposition on soil properties in three adjacent plant communities at a semi-arid site in south-east Spain. Rabbit faecal pellets had concentrations of total N and P comparable to dung of stock animals, with K and Mg somewhat lower, although decomposition rates at this site are evidently very low. There was no significant difference in pH, but conductivity and concentrations of organic C, N (as NH4 + and NO3 –), K, P and Mg in soils from rabbit latrines were significantly greater relative to controls in each community. Barley plants grown as a bioassay of soil fertility had significantly greater total biomass, and lower root : shoot ratios in latrine compared to control soils. There were differences among communities in conductivity and concentrations of N, P and organic C under latrines which were reflected in the bioassay. Although latrines only comprised approximately 0.1% of the ground surface area in each community, they make significant localised contributions to soil fertility and may therefore be important in establishing and maintaining plant cover.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003749900183
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A comparison of direct and indirect methods for measuring leaf and surface areas of individual bushes (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 18 (1995), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Indirect estimates of leaf area from measurements with three commercially available instruments (DEMON, LAI-2000 and Sunfleck Ceptometer) were compared with directly measured areas of individual Retama sphaerocarpa bushes. The three indirect methods gave good estimates of the total surface area of individual bushes. For the DEMON, the method of log-linear averaging of transmitted radiation gave estimates closer to directly measured surface area than the method of averaging transmission linearly. For the LAI-2000, estimated surface area index multiplied by canopy projected area gave the best agreement with directly measured values. For measurements with the Sunfleck Ceptometer, values of surface area estimated from the transmission of photosynthetic quantum flux density, without correcting for diffuse radiation, gave the best agreement with directly measured values. Surface areas estimated by the three instruments were not significantly different from directly measured total (leaf + branch + stem) surface areas. Leaf surface area could be calculated from estimated total surface area minus directly measured branch surface area. Measured branch surface area was linearly related to canopy projected area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1995.tb00193.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Cutting out abbreviations (1977)
    [s.l.] : Nature Publishing Group
    Nature 266 (1977), S. 585-585 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR,-Adrian Smith's suggestion (10 February, page 492) that abbreviated titles of periodicals be replaced by full and accurate citations, will have the sympathy of authors, editors and secretaries. This proposal has already been tested in practice. The British Medical Journal stopped abbreviating ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/266585d0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    C 4 photosynthesis in plants from cool temperate regions, with particular reference to Spartina townsendii (1975)
    [s.l.] : Nature Publishing Group
    Nature 257 (1975), S. 622-624 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] There are two indirect consequences of C4 photosynthesis which could be advantageous to plants irrespective of the climate in their region of origin. First, the ratio of weights of CO2 assimilated to water transpired (the water-use efficiency) of C4 plants, which is often twice that of C3 species4, ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/257622a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The effect of kinetin on stomata of the grass Anthephora pubescens Nees (1977)
    Springer
    Planta 137 (1977), S. 243-245 
    Details
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Anthephora ; Cytokinin Hordeum ; Stomatal aperture ; Transpiration rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transpiration from excised leaves of Anthephra pubescens Nees was enhanced by 1 and 10 mmol m-3 kinetin. Stomatal opening in isolated epidermal strips of A. pubescens under CO2-free air and in the absence of K+ was enhanced by 10 mmol m-3 kinetin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00388157
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Promotion of stomatal opening in the grass Anthephora pubescens nees by a range of natural and synthetic cytokinis (1980)
    Springer
    Planta 150 (1980), S. 218-221 
    Details
    ISSN: 1432-2048
    Keywords: Anthephora ; Cytokinin ; Epidermis ; Stomatal aperture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Stomatal opening in detached epidermis of Anthephora pubescens Nees incubated in the light and CO2-free air was enhanced by each of 6 natural and 4 synthetic cytokinis. Apertures were maximal following incubation with 10 mmol m-3 cytokinin in PIPES buffer for all except N6-[Δ 2-isopentyl] adenine and N6-[Δ 2-sopentyl] adenosine which both opened stomata maximally at 0.1 mmol m-3. Experiments which were undertaken to optimise the conditions of incubation showed that opening was maximal after 3 h incubation and that while 10 mmol m-3 kinetin increased the rate of stomatal opening, it did not affect the duration. Exogenous KCl was not needed for opening and light was saturating even at the low level of 140 μmol m-2 s-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00390829
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Foraging, food selection and worker size in the seed harvesting ant Messor bouvieri (2000)
    Springer
    Oecologia 125 (2000), S. 35-44 
    Details
    ISSN: 1432-1939
    Keywords: Key words Allometry ; Granivory ; Optimal foraging ; Seed predation ; Size matching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Interactions among granivores and seeds depend on the foraging behaviour and morphology of the granivores and on the attributes and availability of seeds. We investigated seed selection by the seed harvesting ant Messor bouvieri in three adjacent plant communities in Spain by relating the harvested seeds to those in the seed rain. Preference was positively correlated with seed size and abundance which accounted for 43% and 20% of the variance respectively. Contrary to predictions of central place foraging theory, the size of seeds harvested did not increase with distance from the nest. Inclusion of a less-preferred item in the diet was more strongly related to the abundance of more-preferred items (60% of the variance) than the abundance of the less-preferred item (14% of the variance). Worker size accounted for 20–30% of the variance in the size of harvested seeds, although small workers did not appear to be constrained by load size for the range of seeds available. The body size of ants was significantly larger in the community with the greatest proportion of large seeds, although this was not due to their ability to carry larger loads or due to the greater force required to crush these seeds. The strong preference of M. bouvieri for large seeds may have important consequences for the plant communities in which they forage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008889
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Promotion of stomatal opening in detached epidermis of Kalanchoe daigremontiana Hamet et Perr. by natural and synthetic cytokinins (1981)
    Springer
    Planta 153 (1981), S. 317-318 
    Details
    ISSN: 1432-2048
    Keywords: Crassulacean acid metabolism ; Cytokinin ; Epidermis ; Kalanchoe ; Stomata, opening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cytokinins kinetin and zeatin increased stomatal opening at 15°C in the dark by up to 50% in detached epidermis of the CAM plant Kalanchoe daigremontiana. Stomata opened maximally following incubation with 10 mmol m-3 cytokinin. This study extends the range of species in which exogenous cytokinins promote stomatal opening.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384249
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Stomatal responses to carbon dioxide of isolated epidermis from a C3 plant, the Argenteum mutant of Pisum sativum L., and a crassulacean-acid-metabolism plant Kalanchoë daigremontiana Hamet et Perr (1985)
    Springer
    Planta 164 (1985), S. 495-500 
    Details
    ISSN: 1432-2048
    Keywords: Carbon dioxide ; C3 plant ; Crassulacean acid metabolism plant ; Epidermis ; Kalanchoë (CO2, stoma) ; Pisum (CO2, stoma) ; Stoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The response of stomata in isolated epidermis to the concentration of CO2 in the gaseous phase was examined in a C3 species, the Argenteum mutant of Pisum sativum, and a crassulacean-acid-metabolism (CAM) species, Kalanchoë daigremontiana. Epidermis from leaves of both species was incubated on buffer solutions in the presence of air containing various volume fractions of CO2 (0 to 10000·10−6). In both species and in the light and in darkness, the effect of CO2 was to inhibit stomatal opening, the maximum inhibition of opening occurring in the range 0 to 360·10−6. The inhibition of opening per unit change in concentration was greatest between volume fractions of 0 and 240·10−6. There was little further closure above the volume fraction of 360·10−6, i.e. approximately ambient concentration of CO2. Thus, although leaves of CAM species may experience much higher internal concentrations of CO2 in the light than those of C3 plants, this does not affect the sensitivity of their stomata to CO2 concentration or the range over which they respond. Stomatal responses to CO2 were similar in both the light and the dark, indicating that effects of CO2 on stomata occur via mechanisms which are independent of light. The responses of stomata to CO2 in the gaseous phase took place without the treatments changing the pH of the buffered solutions. Thus it is unlikely that CO2 elicited stomatal movement by changing either the pH or the HCO 3 − /CO 3 2- equilibria. It is suggested that the concentration of dissolved unhydrated CO2 may be the effector of stomatal movement and that its activity is related to its reactivity with amines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00395965
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Stomatal responses in isolated epidermis of the crassulacean acid metabolism plant Kalanchoe daigremontiana Hamet et Perr. (1981)
    Springer
    Planta 153 (1981), S. 238-245 
    Details
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Crassulacean acid metabolism ; Epidermis ; Kalanchoe ; Potassium ; Stomates, aperture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The optimal conditions for opening of stomata in detached epidermis of the Crassulacean Acid Metabolism (CAM) plant Kalanchoe daigremontiana were determined. Stomatal opening in CO2−free air was unaffected by light so subsequently all epidermal strips were incubated in the dark and in CO2−free air. Apertures were maximal after 3 h incubation and were significantly greater at 15° C than 25° C. Thus stomata in isolated epidermis of this species can respond directly to temperature. Stomatal opening was greatest when the incubating buffer contained 17.6 mol m−3 K+, but decreased linearly with increasing K+ concentrations between 17.6 and 300 mol m−3; the decrease in aperture was shown to be associated with increasing osmotic potentials of the solutions. Reasons for this behaviour, which differs from that of many C3 and C4 species, are discussed. Stomatal apertures declined linearly upon incubation of epidermis on buffer solutions containing between 10−11 and 10−5 mol m−3 abscisic acid (ABA). Hence stomata on isolated epidermis of K. daigremontiana respond to lower concentrations of ABA than those of any species reported previously.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00383893
    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...