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  • 1
    Electronic Resource
    Electronic Resource
    Environmental control of CO2-assimilation and leaf conductance in Larix decidua Mill. (1981)
    Springer
    Oecologia 50 (1981), S. 54-61 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary CO2-assimilation and leaf conductance of Larix decidua Mill. were measured in the field at high (Patscherkofel, Austria) and low (Bayreuth, Germany) elevation in Europe, and outside its natural range along an altitudinal gradient in New Zealand. Phenology of leaf and stem growth showed New Zealand sites to have much longer growing seasons than in Europe, so that the timberline (1,330 m) season was almost twice as long as at the Austrian timberline (1,950 m). The maximum rates of photosynthesis, A max, were similar at all sites after completion of leaf growth, namely 3 to 3.5 μmol m-2 s-1. Only the sun needles of the Bayreuth tree reached 3.5 to 5 μmol m-2 s-1. Light response curves for CO2-assimilation changed during leaf ontogeny, the slope being less in young than in adult leaves. The temperature optimum for 90% of maximum photosynthesis was at all sites similar between ca. 12–28°C for much of the summer. Only at the cooler high altitude timberline sites were optima lower at ca. 10–16°C in developing needles during early summer. A linear correlation existed between A max and leaf conductance at A max, and this showed no difference between the sites except for sun needles at Bayreuth. Leaf conductance responded strongly to light intensity and this was concurrent with the light response of CO2-uptake. A short-term and a long-term effect were differentiated. With increasing age maximum rates of CO2-uptake and leaf conductance at A max increased, whereas short-term response during changes in light declined. The stomata became less responsive with increasing age and tended to remain open. The stomatal responses to light have a significant effect on the water use efficiency during diurnal courses. A higher water use efficiency was found for similar atmospheric conditions in spring than in autumn. Stomata responded with progressive closure to declining air humidity in a similar manner under dissimilar climates. Humidity response thus showed insensitivity to habitat differences. From the diurnal course of gas-exchange stomata were more closed at timberline (1,330 m) than at lower elevations but this did not lead to corresponding site differences in CO2-exchange suggesting Larix may not be operating at high water use efficiency when air is humid. The main difference between habitats studied was in the time necessary for completion of needle development. Similarity in photosynthesis and leaf conductance existed between sites when tree foliage was compared at the same stage of development. Length of growing season and time requirement for foliar development appear to be a principle factor in the carbon balance of deciduous species. The evergreen habit may be more effective in counterbalancing the effects of cool short summers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378793
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  • 2
    Electronic Resource
    Electronic Resource
    Performance of two Picea abies (L.) Karst. stands at different stages of decline (1990)
    Springer
    Oecologia 82 (1990), S. 158-161 
    Details
    ISSN: 1432-1939
    Keywords: Air pollution ; Acid rain ; Photosynthesis ; Nutrition ; Picea abies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Photosynthetic rates and nutrient contents of spruce needles were measured in a region with high levels of air pollution in NE Bavaria, Germany (FRG), and compared to spruce grown under clean air conditions at Craigieburn, in the South Island of New Zealand (NZ). The absolute rates of CO2 uptake, the slope of the CO2 response curve at 240 μl l−1 internal CO2 concentration, and the change of photosynthetic rates with needle age at ambient and saturated CO2 concentrations were virtually identical at both measuring sites. These results confirm an earlier conclusion, that there is no long-term effect of atmospheric pollutants directly on photosynthetic CO2 uptake rates with persistent exposure at the FRG site to high levels of anthropogenic air pollution. Photosynthetic capacity at saturating CO2 concentration was three times higher in the NZ spruce. Needles with high photosynthetic capacity in NZ had lower nitrogen and higher calcium concentrations per unit dry weight but higher concentrations of nitrogen, phosphorus, potassium, magnesium and calcium per unit leaf area, and twice the specific leaf weight.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323529
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  • 3
    Electronic Resource
    Electronic Resource
    Nitrogen fixation byAlnus viridis (Chaix) DC. (1970)
    Springer
    Plant and soil 33 (1970), S. 30-48 
    Details
    ISSN: 1573-5036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary InAlnus viridis nodule growth relative to plant growth was inversely related to the quantity of nitrate added to nutrient solutions. Nodulated plants showed maximum growth when grown independently of supplied nitrogen and made better growth in its absence than unnodulated plants at any level of added nitrogen. Low levels of nitrate caused a depression of growth of nodulated plants, apparently by suppressing both nitrogen fixation and nodule growth. Nodules in nitrogen-free sand culture fixed atmospheric nitrogen at a rate of 6.6 mg/day/g nodule. Phosphorus deficiency was induced by low levels of phosphate and resulted in small plants with dark-green foliage. Root and nodule growth as a percentage of total plant growth and the percentage of total accumulated plant nitrogen below ground were greater at a root temperature of 11°C than 21°C. Thus at low root temperature processes other than nitrogen fixation were limiting to plant growth. Excised nodules were exposed to an N 2 15 -enriched atmosphere. A positive correlation between rate of nitrogen fixation and temperature was obtained, with optimum fixation occurring at about 20°C. It was shown that in spite of decreasing mean temperatures with increase in altitude, rate of nitrogen fixation by nodules of plants growing in the field increased with increase in altitude. This latter trend was deduced to be a reflection of the extent to which the field sites were nitrogen deficient in relation to climatically possible growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01378194
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  • 4
    Electronic Resource
    Electronic Resource
    The influence of soil moisture on water potential, transpiration and photosynthesis of conifer seedlings (1978)
    Springer
    Plant and soil 49 (1978), S. 91-103 
    Details
    ISSN: 1573-5036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The influence of soil moisture content and soil water potential on plant water potential, transpiration and net-photosynthesis of potted larch (Larix decidua), spruce (Picea abies) and pine (Pinus cembra) was studied under constant and close to optimum conditions in a laboratory. The ‘equilibrium’ plant water potential measured under ‘non-transpiring’ conditions came close to soil water potential, but in moist soil the equilibrium potential was slightly lower, particularly in larch where transpiration was not fully arrested. In very dry soil, plants had higher water potential than soil, presumably due to roots exploiting the wettest points within the soil. Pine, spruce and larch utilised a large part of soil moisture (down to 25wt.% soil water content or −1.5 bars potential) while maintaining plant water potential near −8, −9.5 and −12.5 bars respectively. A similar pattern occurred in dry soil. The differences between species are explained by differing stomatal sensitivity to water potential. Pine began a gradual reduction in gas-exchange below a soil water potential of −0.4 bars. Larch showed no marked reduction until the soil potential fell to −3.5 bars but below this the shut-down in gas-exchange was rapid. Spruce lay in between. In spite of the early and sensitive gas-exchange reduction with decreasing soil moisture, pine maintained the highest net photosynthesis/transpiration ratio and thus used limited soil water more slowly and economically than the other species. Seedlings maintained a higher rate of gas-exchange in strong light than in weak light, especially at low soil water potentials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02149911
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  • 5
    Electronic Resource
    Electronic Resource
    Symbionts of alder nodules in New Zealand (1969)
    Springer
    Plant and soil 30 (1969), S. 145-149 
    Details
    ISSN: 1573-5036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Micro-organisms capable of forming effective nodules on roots ofAlnus viridis have been found to be present in New Zealand soils. It is concluded that endemic soil organisms suitable for nodulation ofAlnus viridis occur, and cross inoculation trials have indicated that there are probably differences between organisms forming nodules with various species of alders.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01885276
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  • 6
    Electronic Resource
    Electronic Resource
    Nitrogen fixation byAlnus viridis (Chaix) DC. (1970)
    Springer
    Plant and soil 33 (1970), S. 30-48 
    Details
    ISSN: 1573-5036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary InAlnus viridis nodule growth relative to plant growth was inversely related to the quantity of nitrate added to nutrient solutions. Nodulated plants showed maximum growth when grown independently of supplied nitrogen and made better growth in its absence than unnodulated plants at any level of added nitrogen. Low levels of nitrate caused a depression of growth of nodulated plants, apparently by suppressing both nitrogen fixation and nodule growth. Nodules in nitrogen-free sand culture fixed atmospheric nitrogen at a rate of 6.6 mg/day/g nodule. Phosphorus deficiency was induced by low levels of phosphate and resulted in small plants with dark-green foliage. Root and nodule growth as a percentage of total plant growth and the percentage of total accumulated plant nitrogen below ground were greater at a root temperature of 11°C than 21°C. Thus at low root temperature processes other than nitrogen fixation were limiting to plant growth. Excised nodules were exposed to an N 2 15 -enriched atmosphere. A positive correlation between rate of nitrogen fixation and temperature was obtained, with optimum fixation occurring at about 20°C. It was shown that in spite of decreasing mean temperatures with increase in altitude, rate of nitrogen fixation by nodules of plants growing in the field increased with increase in altitude. This latter trend was deduced to be a reflection of the extent to which the field sites were nitrogen deficient in relation to climatically possible growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01378194
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    The influence of different mycorrhizae on growth, nutrition and gas-exchange of Pinus mugo seedlings (1974)
    Springer
    Plant and soil 40 (1974), S. 21-32 
    Details
    ISSN: 1573-5036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The mycorrhizae on seedlings of Pinus mugo Turra were superseded by other types after seedlings were transplanted from a nursery to a subalpine pine soil. The mycorrhizae formed by a single symbiont, Hebeloma mesophaeum (Pers. ex Fr.) Quel, were more efficient in terms of seedling nutrition than mycorrhizae formed by the natural fungus population from a native site. This led to significant differences in growth of needles, and their rates of photosynthesis and transpiration. re]19721213
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00011406
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