ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Amsterdam : Elsevier
    Environmental Pollution 85 (1994), S. 185-189 
    ISSN: 0269-7491
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Trees 1 (1987), S. 219-224 
    ISSN: 1432-2285
    Keywords: Larix ; Heterosis ; Photosynthesis ; Stomatal conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Individual 33-year-old forest trees of the deciduous conifer speciesLarix decidua, Larix leptolepis andLarix decidua x leptolepis were investigated with respect to the phenomenon of stem heterosis in hybrid larch; the first part of this study compares the gas exchange responses of leaves. CO2 assimilation per leaf area was similar in the three larch species, but on a dry weight basis the nitrogen content of the needles and maximum CO2 assimilation rate (Amax) were slightly higher in the hybrid. This increase was accompanied by a higher protein content than in the Japanese and a lower specific leaf weight than in the European larch. All three species were similar in terms of the photosynthetic “nitrogen use” and stomatal conductance atA max. The similar slopes of the area-related steady-state responses of gas exchange against irradiance, evaporative demand and internal CO2 concentration led to similar rates of CO2 uptake under ambient conditions. The natural combinations and variability of the environmental factors also reduced the small dry weight-related difference inA max between hybrid larch and the parent species, such that all trees achieved similar daily carbon gains. Thus, the ecological significance of small interspecific differences in the metabolism of leaves has very little effect under the natural habitat conditions of a temperate climate. The second part of the study will investigate the effect of growth characteristics on the heterosis of hybrid larch.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Trees 1 (1987), S. 225-231 
    ISSN: 1432-2285
    Keywords: Larix ; Heterosis ; Growth ; Branching pattern ; Needle density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Among 33-year-old forest trees ofLarix decidua, L. leptolepis andL. decidua x leptolepis, the hybrid possessed an above-ground biomass which was three times greater, although all larches displayed similar relative distributions of biomass. At a “relative growth rate” slightly lower than in the parent species, hybrid larch achieved twice the annual carbon gain, increment in stem length and above-ground production, and its foliage-related stem growth was higher than in European (L. decidua) but similar to Japanese (L. leptolepis) larch. A similar “relative growth efficiency” and foliage-related total above-ground production in all trees did reflect the similarity of photosynthetic capacity of the hybrid found at the leaf level. While the lengths of lateral twigs on hybrid branches were intermediate between the European larch with short, and the Japanese larch with large, twigs the hybrid possessed the longest branches with the highest needle biomass. This resulted in a crown structure of the hybrid crown similar to the Japanese larch together with a high needle density on branches as in the European larch. In total, the foliage biomass per crown length was about 30% higher in hybrid larch than in both of the parent species. Thus, the high carbon input for the stem heterosis was based on a “complementation principle” of advantageous parent features at the crown level. Similar slopes of foliage against sapwood area of stem and branches did not indicate a special need for a thick hybrid stem with respect to water transport.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-2285
    Keywords: Larix ; Carbon uptake ; Respiration ; Carbon balances ; Water loss ; Sun and shade branches
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Shade needles of hybrid larch (Larix decidua × leptolepis) had the same rates of photosynthesis as sun needles per dry weight and nitrogen, and a similar leaf conductance under conditions of light saturation at ambient CO2 (Amax). However, on an area basis, Amax and specific leaf weight were lower in shade than in sun needles. Stomata of sun needles limited CO2 uptake at light saturation by about 20%, but under natural conditions of light in the shade crown, shade needles operated in a range of saturating internal CO2 without stomatal limitation of CO2 uptake. In both needle types, stomata responded similarly to changes in light, but shade needles were more sensitive to changes in vapor pressure deficit than sun needles. Despite a high photosynthetic capacity, the ambient light conditions reduced the mean daily (in summer) and annual carbon gain of shade needles to less than 50% of that in sun needles. In sun needles, the transpiration per carbon gain was about 220 mol mol−1 on an annual basis. The carbon budget of branches was determined from the photosynthetic rate, the needle biomass and respiration, the latter of which was (per growth and on a carbon basis) 1.6 mol mol−1 year−1 in branch and stem wood. In shade branches carbon gains exceeded carbon costs (growth + respiration) by only a factor of 1.6 compared with 3.5 in sun branches. The carbon balance of sun branches was 5 times higher per needle biomass of a branch or 9 times higher on a branch length basis than shade branches. The shade foliage (including the shaded near-stem sun foliage) only contributed approximately 23% to the total annual carbon gain of the tree.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0931-1890
    Keywords: Key words Betula pendula ; Ozone ; Nutrition ; Photosynthesis ; Stomatal conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Cuttings of a single birch clone (Betula pendula) were grown in field fumigation chambers throughout the growing season in either filtered air (control) or 90/40 nl O3 l–1 (day/night). Both regimes were split into plants under high and low nutrient supply (macro- and micronutrients). The stomatal density of leaves was increased by ozone but was lowered at high nutrition, while the inner air space was hardly affected by the treatments. Ozone induced macroscopic leaf injury regardless of nutrition, but leaf shedding was delayed in the low-fertilized plants, despite O3 uptake being similar to that in high-fertilized plants. The leaf turn-over was enhanced in the O3-exposed high-fertilized plants, but length growth and leaf formation of stems were not affected by ozone in either nutrient regime. Leaves of high-fertilized plants showed O3-caused decline in photosynthetic capacity, water-use efficiency, apparent carbon uptake efficiency and quantum yield earlier as compared with low-fertilized plants, whereas chlorophyll fluorescence (FV/FM) and leaf nitrogen concentration were rather stable. CO2 uptake rate and rubisco activity of young leaves compensated for the O3 injury in the ageing leaves of the low-fertilized plants. In 8-week-old leaves, however, the O3-induced decline in CO2 uptake did not differ between the nutrient regimes and was associated with increased dark respiration rather than changed photorespiration. The balance between CO2 supply and demand was lost, as was stomatal limitation on CO2 uptake. High nutrition did not help leaves to maintain a high photosynthetic capacity and life span under O3 stress.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Trees 12 (1997), S. 11-20 
    ISSN: 0931-1890
    Keywords: Key words Betula pendula ; Ozone ; Nutrition ; Carbon balance ; Water-use efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Cuttings of a single birch clone (Betula pendula) were grown in field fumigation chambers throughout the growing season in either filtered air (control) or 90/40 nl O3 l–1 (day/night), both regimes being split into high and low nutrient supply. High nutrition was neither advantageous for maintaining the photosynthetic capacity and life span of the leaves (see Maurer et al. 1997) nor for limiting the productive loss of the whole plant under O3 stress relative to low-fertilized (LF) plants. However, nutrition determined, through carbon allocation and leaf turn-over, the way plants coped with O3 impact. High leaf turn-over under O3 stress related the carbon gain of high-fertilized (HF) plants to the photosynthesis of newly formed, intact leaves, although the foliage area remained reduced (shedding of O3-injured leaves, inhibited branching). In contrast, the low leaf turn-over of LF plants reflected the maintenance of the O3-injured leaves, causing high respiratory costs in the whole-plant carbon balance and a root/shoot biomass ratio as low as in the HF plants. Within the root system, the carbon allocation was determined by nutrition rather than ozone, whereas the water-use efficiency of the whole-plant carbon increment was lowered by ozone in both nutrient regimes. The relationship between biomass production and nutrient levels in the whole plant was hardly affected by ozone, with only the range of interaction being narrowed. Conditions requiring the maintenance of foliage rather than favoring the replacement of O3-injured leaves may render trees more susceptible to shifts in the carbon allocation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 14 (1991), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract. Wphen there is no external source of water, plants can grow by mobilizing internal water from nongrowing tissues. We investigated how this internal water moves by measuring continuously and simultaneously the water potential (ψw) of soybean (Glycine max L. Merr.) seedlings in the upper, growing stem tissues and the lower, non-growing stem tissues. When external water was available to the roots, the stems grew rapidly and the ψw of the growing tissue was continually below that of the nongrowing tissue and the medium around the roots. This indicated that a growth-induced gradient in ψw favoured water movement from the external source to the growing cells. When the external source was removed, the ψw of the growing tissue remained constant for a time and the ψw of the nongrowing tissue decreased somewhat. Growth took place slowly as water was withdrawn from the nongrowing tissue but ψw gradients continued to favour water transport to the growing cells. On the other hand, if this internal source was removed by excision, growth ceased abruptly. In this case, the cell walls relaxed and the ψw of the growing tissue decreased by about 0.1 MPa instead of remaining constant. The ψw of the detached nongrowing tissues remained constant instead of decreasing. This indicates not only that water mobilization required attached nongrowing or slowly growing tissues but also that mobilization affected wall relaxation. Thus, ψw differences may mobilize internal water, may explain the continued growth of plants and plant parts removed from external sources of water, and may account for discrepancies in measurements of cell wall properties in growing tissues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 14 (1991), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract. Water uptake is required when plants enlarge but growth may also occur when no external water is present. To determine whether this growth also depends on water, we studied etiolated seedlings of soybean (Glycine max L. Merr.) deprived of external water by transplanting to vermiculite of low water content or by transferring to water-saturated air. When the external water supply was decreased or removed, the roots continued to grow rapidly but the stems abruptly decreased in growth (in 1 min) and continued to grow slowly. The stem tissues gained water content in the upper elongating region and lost water content in the basal region. Removal of the basal stem caused growth to slow further. When all tissues surrounding the stem elongating region were removed simultaneously, stem growth decreased abruptly to near zero. Control experiments showed that the decreased growth was not caused by wounding or the removal of the auxin or nutrient supply. It is concluded that growth always depended on a source of water and, when external supplies were absent, internal water was mobilized to enlarging tissues of shoots and roots mostly from the basal stem tissues in these seedlings.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Water, air & soil pollution 116 (1999), S. 199-226 
    ISSN: 1573-2932
    Keywords: Tropospheric ozone ; Forests ; Ecological risk analysis ; Critical levels ; Free-air fumigation ; Visible injury ; European Alps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Tropospheric ozone (O3) may adversely affect tree growth, with critical levels for O3 being exceeded in many parts of Europe. However, unequivocal evidence for O3-induced foliar injury on woody species under field conditions has only been found in a few places. Visible O3 injury appears to occur mainly in the Mediterranean Basin, which is also the area where the least amount of information is available on O3 exposure as well as the sensitivity of individual species. Overall, the quantitative risk assessment of O3 impacts on mature trees and forests is vague at the European scale, as most knowledge is derived from controlled O3 fumigations of young trees, grown in isolation in exposure chambers. Research suggests that risks exist, but these need to be validated for stand conditions. O3-induced changes in resource allocation rather than productivity appear to be crucial as they affect competitiveness and predisposition to parasite attack and may eventually lead to the loss of genetic diversity. ‘Free-air’ O3 fumigations in forest canopies may reveal processes that are susceptible to O3 stress under field conditions and provide a scientific basis towards quantitative risk assessment and realistic definitions of critical levels for O3 in forest ecosystems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-2932
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...