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  • 1
    ISSN: 1432-1939
    Keywords: Picea abies ; Forest decline ; Xylem flow ; Whole tree transpiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The water relations of Picea abies in a healthy stand with green trees only and a declining stand with trees showing different stages of needle yellowing were investigated in northern Bavaria. The present study is based on observations of trees differing in their nutritional status but apparently green on both sites in order to identify changes in the response pattern which might be caused by atmospheric concentrations of air pollutants and could lead to the phenomenon of decline. Transpiration was measured as water flow through the hydroactive xylem using an equilibrium mass-flow measurement system. Total tree transpiration was monitored diurnally, from July 1985 until October 1985 at both sites. The relationship between transpiration and meteorological measurements indicated that transpiration was a linear function of the vapor pressure deficit. No differences in transpiration of green trees were observed between the two sites. Canopy transpiration was 57%–68% of total throughfall and 41%–54% of total rainfall. Due to this positive water balance, soil water potential at 10 and 20 cm depths remained close to-0.02 MPa (max.-0.09 MPa) for most of the summer. Soil water potential was correlated with the difference between the weekly precipitation and transpiration. No differences in the water relations of apparently healthy trees in the two P. abies stands were observed. It is concluded that differences between green trees at the two sites in terms of nutrient relations or growth rate cannot be explained by changes in whole-tree transpiration or soil water status.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 77 (1988), S. 163-173 
    ISSN: 1432-1939
    Keywords: Forest decline ; Spruce (Picea abies) ; Nutrients ; Growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A declining, closed-canopy Picea abies (L.) Karst. stand produced as much crown biomass as a healthy stand, although some trees were chlorotic due to magnesium deficiency. The production of wood per unit of leaf area in both stands was related to the foliar magnesium concentration. Although leaf area index and climate were similar at both sites, stemwood production was 35% lower in the declining than in the healthy stand. Nutritional disharmony, rather than a deficiency in a single element, was identified as the mechanism for reduced tree vigor. The role of nutrient stress in forest decline was detected by partitioning the season into three periods reflecting different phenological stages: a canopy growth period in spring, a stem growth period in summer, and a recharge period during the non-growing season. Needle growth was associated with nitrogen supply. Most of the magnesium supply required to meet the demand for foliage growth was retranslocated from mature needles. Magnesium retranslocation was related to concentration of nitrogen and magnesium in those needles before bud break. Retranslocation from mature needles during the phase of canopy production resulted in chlorosis in initially green needles if the magnesium concentration before bud break was low. Nitrogen concentration in 0-year-old needles generally remained constant with increasing supply, indicating that foliage growth was restricted by the supply of nitrogen. In contrast, magnesium concentration generally increased with supply, indicating that magnesium supply for needle growth was sufficient. Much of the magnesium required for wood production was taken up from the soil because stored magnesium was largely used for canopy growth. Uptake at the declining site was probably limited because of restricted root expansion and lower soil magnesium compared to the healthy site. For this reason only wood growth was reduced at the declining site. Because the recharge of magnesium during the non-growing period is dependent on uptake from the soil, it was more limited at the declining that at the healthy stand. However, as nitrogen uptake from the atmosphere may account for an appreciable proportion of the total uptake, and as its supply in the soil at both sites was similar, an unbalanced recharge of nitrogen and magnesium may have occurred at the declining site. If mature needles are unable to recharge with magnesium in proportion to the uptake of nitrogen, chlorosis is likely to occur during the next canopy growth period.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1939
    Keywords: Forest decline ; Ectomycorrhizas ; Fine roots ; Picea abies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of root tips and apparent ectomycorrhizas was compared in the Fichtelgebirge (FRG) over one growing season in two 30-year-old Picea abies stands, both on soils derived from phyllite but showing varying symptoms of decline. Visual symptoms of tree decline reflected a lower relative and absolute mycorrhizal frequency, a lower number of ectomycorrhizas per m2 leaf area and an uneven vertical distribution of root tips and ectomycorrhizas. The number of apparent ectomycorrhizas per ground area was correlated with the amount of magnesium, calcium, and ammonium, and the pH in the free-drainage soil solution, and with the molar calcium to aluminium ratio in mineral soil extracts. The foliage concentrations of magnesium and calcium were correlated with the numbers of apparent ectomycorrhizas per m2 leaf or ground area. These observations were used to formulate testable hypotheses concerning the role of the root system and the soil environment in forest decline.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1939
    Keywords: Forest decline ; Carbohydrates ; Picea abies ; Growth ; Leaf area index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This is the first in a series of papers on the growth, photosynthetic rate, water and nutrient relations, root distribution and mycorrhizal frequency of two Norway spruce forests at different stages of decline. One of the stands was composed of green trees only while the other included trees ranging in appearance from full green crowns to thin crowns with yellow needles. In this paper we compare the growth and carbohydrate relations of the two stands and examine relationships among growth variables in ten plots. The declining stand produced 65 percent of the wood per ground area compared with the stand in which all trees were green because its foliage produced less wood at any level of leaf area index. The difference in foliage efficiency between the sites could not be explained by differeneces in climate, competition or stand structure. The declining stand appeared to have lower carbon gain as indicated by a smaller increase in reserve carbohydrates before bud break, and weaker sinks for carbohydrates as indicated by less use of the stored carbohydrates than the healthy stand. Thus, growth reduction was probably related to factors which affect both photosynthesis and, even more, the sinks for carbohydrate.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 42 (1986), S. 115-120 
    ISSN: 1420-9071
    Keywords: Forest decline ; peace with nature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1)Peace with nature means that human relations with other beings are controlled constitutionally within a community to which not only mankind belongs. Constitutionally restricted and in this sense non-violent, human domination is legitimate. 2) What we are allowed to do depends on who we are. Mankind is the species in which nature emerges to express herself in language, art and reason, and in doing so she moves herself forward with us. 3) How we should relate ourselves to nature also depends on our understanding of nature. Nature basically is acting nature, or creative power, and in this sense equally is the nature of the beings of nature. 4) Some artifacts are more natural and correspond to peace with nature better than others which are unnatural and violate peace with nature. Also in our fellow world, and even apart from man's influence, nature is whatought to be. 5) The technologically less advanced countries should not repeat the mistakes of the industrialized countries. The traditional pattern of industrial economy cannot be generalized to all peoples and violates peace with nature. 6) Plants are not only most sensitive indicators to environmental pollution but to the loss of humanity as well.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Low-Temperature Synthesis of Oxyhalides, YOX (X = Cl, Br, I), as the Source of Impurity in the Preparation of Trihalides, YX3, via the Ammonium Halide Route. Analogy of YOCl and YSClAmmonium halides, NH4X (X = Cl, Br, I), react with Y2O3 and Y2S3, respectively, at temperatures as low as 230=C (X = Cl), 280=C (Br), and 360=C (I) (molar ratio 12:1) to yield (NH4)3YX6, NH3, and H2O (H2S). The choice of smaller ratios than 12:1 (for example 2:1) results in the formation of oxyhalides, YOX, via the reaction of (NH4)3YX6 with surplus Y2O3. This reaction is therefore the actual source of impurity of rare-earth trihalides in their preparation via the ammonium halide routes.
    Notes: Ammoniumhalogenide, NH4X (X = Cl, Br, I), reagieren mit Y2O3 bzw. Y2S3 (im molaren Verhältnis 12:1) bereits bei Temperaturen um 230°C (X = Cl), 280°C (Br) bzw. 360°C (I) unter Bildung von (NH4)3YX6, NH3 und H2O (H2S). Wird das Verhältnis NH4X:Y2O3 kleiner als 12:1 gewählt (z. B. 2:1), so entstehen Oxidhalogenide YOX durch Reaktion von (NH4)3YX6 mit „überschüssigem“ Y2O3. Diese Reaktion ist somit die Quelle der Verunreinigungen von Selten-Erd-Halogeniden durch Oxidhalogenide bei ihrer Gewinnung nach der Ammoniumhalogenid-Methode.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 533 (1986), S. 181-185 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxychlorides under Reducing Conditions: Single Crystals of NdOCl and GdOClSingle crystals of NdOCl and GdOCl are obtained in metallothermic reduction reactions of NdCl3 and GdCl3, respectively, with sodium due to ubiquitous oxidic impurities by crystallization from the melt. The crystal structures of NdOCl [a = 402.49(2), c = 678.37(5) pm] and GdOCl [a = 394.95(3), c = 667.08(7) pm], both PbFCl structure type (P4/nmm, Z = 2) were refined.
    Notes: Bei der metallothermischen Reduktion von NdCl3 bzw. GdCl3 mit Natrium werden, durch kaum vermeidbare oxydische Verunreinigungen bedingt, Einkristalle von NdOCl bzw. GdOCl durch Kristallisation aus der Schmelze erhalten. Die Kristallstrukturen (PbFCl-Typ, P4/nmm, Z = 2) wurden verfeinert. Es ist: a = 402,49(2); c = 678,37(5) pm (NdOCl) und a = 394,95(3); c = 667,08(7) pm (GdOCl).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 408 (1974), S. 15-20 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Notice on the Magnetic Behaviour of Li3CrO4Li3CrO4, a smaragd green powder, is due to powder photographs (Guinier-Simon-technique) isotypic with orthorhombic HT—Li3PO4, a = 6.309, b = 10.851, c = 4.952 Å, Z = 4. Between 298 and 10K the Curie-Weiss-Law is obeyed with μ=1.60 B.M. and Θ=+10 K. Below 5 K ferromagnetism is observed. ESR measurements at 4.2 K and more pronounced at 1.8 K show anisotropy of the ligand field.
    Notes: Li3CrO4, ein smaragdgrünes Pulver, ist nach Guinier-Simon-Aufnahmen isotyp mit HT-Li3PO4, a = 6,309 Å, b = 10,851 Å, c = 4,952 Å, Z = 4. Zwischen 298 und 10 K wird das Curie-Weisssche Gesetz mit μ=1,60 B.M., Θ=+10K befolgt. Unterhalb von 5 K tritt überraschend Ferromagnetismus auf. ESR-Messungen bei 4,2 K und ausgeprägter bei 1,8 K zeigen eine Anisotropie des Ligandenfeldes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 408 (1974), S. 275-282 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Dinitrito Cobalt(III) Complexes. I. Preparation and Absorption Spectra of Di(ethylenediamine) Cobalt(III) PerchloratesCis and trans dinitrito diethylenediamine cobalt perchlorates could be prepared starting with carbonato and trans dichloro ethylenediamine cobalt perchlorate. Spectroscopic data are reported and compared with those of the corresponding dinitro complexes.
    Notes: Ausgehend von Carbonato- und trans-Dichloro-diäthylendiaminkobalt(III)-perchlorat konnten cis- und trans-Dinitrito-diäthylendiamin-kobalt(III)-perchlorate dargestellt werden. Ihre Spektren im sichtbaren Gebiet und UV werden mitgeteilt und mit den Spektren der entsprechenden Dinitrokomplexe verglichen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 528 (1985), S. 55-60 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Divalent Neodymium: NdCl2 and KNd2Cl5Single crystals of NdCl2 have been obtained via metallothermic reduction of NdCl3 with lithium: a = 908.49(5), b = 761.47(5), c = 455.62(2) pm, Pbnm, Z = 4, PbCl2 type, refined to R = 0.047. Reduction of NdCl3 with potassium yields KNd2Cl5: a = 894.51(9), b = 785.16(7), c = 1 265.28(13) pm, β = 90.000(8)°, P21/c, Z = 4, isotypic with TlPb2Cl5. There is a close structural relationship of KNd2Cl5 with K2NdCl5.
    Notes: Bei der „metallothermischen Reduktion“ von NdCl3 mit Lithium werden Einkristalle von NdCl2 erhalten: a = 908,49(5); b = 761,47(5); c = 455,62(2) pm; Pbnm, Z = 4, PbCl2-Typ, Verfeinerung bis R = 0,047. Kalium reduziert NdCl3 unter Bildung von KNd2Cl5: a = 894,51(9); b = 785,16(7); c = 1265,28(13) pm; β = 90,000(8)°, P21/c, Z = 4, isotyp mit TlPb2Cl5. Es besteht eine enge strukturelle Verwandtschaft mit K2NdCl5.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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