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1.
Effects of N addition and drought on ectomycorrhizae of Norway spruce trees were investigated in an outdoor pot lysimeter study. Three levels of N were applied as ammonium nitrate in irrigation water for five years; ambient rainwater (N0) and 5 (N5) and 15 (N15) times this N concentration. Mean annual N addition during the five years corresponded to 5, 27 and 82 kg·ha-1·y-1 for the N0, N5 and N15 treatments, respectively. During the third and fifth growth seasons two levels (lengths) of drought were artificially induced in addition to a watered control. Soil cores taken from each pot lysimeter were analyzed for mycorrhizal colonization and ectomycorrhizae were categorized according to macroscopic morphology. Drought decreased mycorrhizal colonization significantly. There was a significant interaction of drought and N effects on reduction of the mycorrhizal colonization. Although all of the mycorrhiza types were influenced by drought, only Cenococcum geophilum showed a significant change. N treatment alone did not show any significant effect either on mycorrhizal colonization or mycorrhizal types. 相似文献
2.
Didier Le Thiec Martin Dixon Pascal Loosveldt Jean Pierre Garrec 《Trees - Structure and Function》1995,10(2):55-62
Norway spruce and red oak trees were planted directly into the soil and enclosed in open-top chambers. For 2 years the trees were exposed to both ambient and elevated CO2 concentrations (700 mol mol-1) and during this time variations in nutrient concentrations were studied. CO2-treated plants had decreases in global leaf concentrations of nitrogen, potassium, calcium and manganese for both species. When different areas of the foliage were analysed however, the response showed much variability between the respective sites and between species. Furthermore the nutrient concentrations changed differently as the plant material aged and this change showed inter-treatment differences. These results show how it may be important to analyse plant material of different ages and at different cell sites when studying nutrient levels. 相似文献
3.
Young Norway spruce trees were grown in 94 pots (2 per pot) on soil substrate derived from granite with low Mg saturation and were fertilized with different amounts of NH4NO3 (in total 25, 61, and 97 kmol N ha-1) over a period of four years, partly at an experimental station, partly at a high-elevation site in the Bavarian Forest. A fourth set of trees received 9.4 kmol Mg ha-1 in addition to 25 kmol N. Depending on the treatment, needle chlorosis developed in the course of the experiment. Improved light conditions after three years accelerated the yellowing process. The chlorotic Norway spruce trees showed a severe Mg deficiency and an imbalanced N:Mg ratio. The shoot length increment, the stem diameter, and the needle weights however were not influenced by the fertilization. Excessive applications of NH4NO3caused the substrate to become depleted of Mg. The successful experimental induction of the characteristic tip yellowing of older needles of Norway spruce growing on acidic soils at higher altitudes allowed hypotheses on the causes and processes of this type of forest decline to be tested. 相似文献
4.
Nitrogen transformations in limed and nitrogen fertilized soil in Norway spruce stands 总被引:3,自引:0,他引:3
Nitrogen transformations in the soil, and the resulting changes in carbon and nitrogen compounds in soil percolate water, were studied in two stands of Norway spruce (Picea abies L.). Over the last 30 years the stands were repeatedly limed (total 6000 kg ha–1), fertilized with nitrogen (total about 900 kg ha–1), or both treatments together. Both aerobic incubations of soil samples in the laboratory, and intact soil core incubations in the field showed that in control plots ammonification widely predominated over nitrification. In both experiments nitrogen addition increased the formation of mineral-N. In one experiment separate lime and nitrogen treatments increased nitrification, in the other, only lime and nitrogen addition together had this effect. In one experiment immobilization of nitrogen to soil microbial biomass was lower in soil only treated with nitrogen. Soil percolate water was collected by means of lysimeters placed under the humus layer and 10 cm below in the mineral soil. Total N, NH4-N and NO3-N were measured, and dissolved organic nitrogen was fractioned according to molecular weight. NO3-N concentrations in percolate water, collected under the humus layer, were higher in plots treated with N-fertilizer, especially when lime was also added. The treatments had no effect on the N concentrations in mineral soil. A considerable proportion of nitrogen was leached in organic form. 相似文献
5.
Michael Lippert Karl-Heinz Häberle Karl Steiner Hans-Dieter Payer Karl-Eugen Rehfuess 《Trees - Structure and Function》1996,10(6):382-392
To study the single and combined effects of elevated carbon dioxide (CO2), ozone (O3), nitrogen nutrition, and water supply on photosynthetic gas exchange and biomass accumulation of Norway spruce, a four-factorial experiment was conducted in closed environmental chambers. Each factor was applied at two levels: (i) ambient and elevated (ambient + 200 μl 1-1) CO2, (ii) 20 and 80 nl 1-1 O3, (iii) low and high nitrogen fertilization, and (iv) a well watered and a drought treatment. Neither elevated O3 nor CO2 significantly changed stomatal conductances of spruce needles. Adverse effects of elevated O3 on photosynthetic parameters such as net assimilation rate and carboxylation efficiency occurred only when the plants were well watered and in a good nutritional status. After 6 weeks enhanced atmospheric CO2 resulted in increased net assimilation rates provided that nutrition was well balanced and plants were well watered. Acclimation processes became apparent and are interpreted as a consequence of sink regulation. While O3-effects were apparent only in biomass of 1-year-old plant material, elevated CO2 resulted in higher biomass of the buds expanding during the exposure and increased root biomass significantly. Above and below-ground biomass were strongly influenced by the water and nutrition treatments. 相似文献
6.
Three-year-old Norway spruce trees were planted into a low-nitrogen mineral forest soil and supplied either with two different
levels of mineral nitrogen (NH4NO3) or with a slow-release form of organic nitrogen (keratin). Supply of mineral nitrogen increased the concentrations of ammonium
and nitrate in the soil solution and in CaCl2-extracts of the rhizosphere and bulk soil. In the soil solution, in all treatments nitrate concentrations were higher than
ammonium concentrations, while in the soil extracts ammonium concentrations were often higher than nitrate concentrations.
After 7 months of growth, 15N labelled ammonium or nitrate was added to the soil. Plants were harvested 2 weeks later. Keratin supply to the soil did
not affect growth and nitrogen accumulation of the trees. In contrast, supply of mineral nitrogen increased shoot growth and
increased the ratio of above-ground to below-ground growth. The proportion of needle biomass to total above-ground biomass
was not increased by mineral N supply. The atom-% 15N was higher in younger needles than in older needles, and in younger needles higher in plants supplied with 15N-nitrate than in plants supplied with 15N-ammonium. The present data show that young Norway spruce plants take up nitrate even under conditions of high plant internal
N levels.
Received: 1 April 1998 / Accepted: 9 October 1998 相似文献
7.
Three separate experiments were conducted in the nursery using grassland soil as a growing medium. The first experiment was
conducted to assess the nodulation of the two legume trees grown in unamended soil, the second was done to determine the effects
of N-fertilizer application on the interaction of the five Rhizobium isolates withA. falcataria and the third experiment was conducted to determine the effects of liming on theRhizobium × A. mangium interaction.
Three local Rhizobium isolates, A16, A18, and A14 were effective forA. falcataria with A16 as the most promising strain under the conditions described. In general, application of combined nitrogen suppressed nodulation
ofA. falcataria. Nodulation in the absence of combined N exceeded those fertilized with 30 kg N ha−1 by 114.0%, 60 kg N ha−1 by 209.6% and 100 kg N ha−1 by 237.1%.
Two local isolates, Am10 and Am2, and an introduced strain, NA 1533 from Australia were promising forA. mangium. Unlike inA. falcataria, the application of combined nitrogen at the rate of 100 kg N ha−1 did not suppress nodulation inA. mangium. Liming the soil to pH 6.5 regardless of nitrogen fertilizer application improved the performance of the Rhizobium—A. mangium symbiosis. 相似文献
8.
Mathieu Jonard Arnaud Legout Manuel Nicolas Etienne Dambrine Claude Nys Erwin Ulrich Raphaele van der Perre Quentin Ponette 《Global Change Biology》2012,18(2):711-725
Since the late 1970s, several long‐term ecological studies were conducted to better understand the biogeochemical functioning of Norway spruce stands in the Ardennes as these nutrient‐poor ecosystems were subject to high levels of acid deposition and exhibited symptoms of tree health decline. Between 1978 and 2009, acid deposition declined sharply, especially sulfur and to a lesser extent nitrogen deposition. The aim of this study was (i) to determine if the Norway spruce stands recovered after the reduction of acid deposition and (ii) to explain why such a recovery occurred or not. Therefore, we collected data from different projects carried out in the Ardennes to characterize the long‐term temporal trends in soil solution chemistry, foliar nutrition, and crown condition. In parallel, a model describing the nutrient cycling in forests (NuCM) was calibrated and used to check the consistency of the observed temporal trends and to explain them. The soil solution concentration of most of the elements decreased between 1978 and 2002, which was ascribed to a decrease in atmospheric deposition. For potassium, a decline in the exchangeable pool was also showed based on the simulation carried out with NuCM. As nitrogen (N) deposition remained at an elevated level, Norway spruce stands were progressively saturated in N and mineral nutrition became more and more unbalanced. Except the foliar N and Al concentration that remained constant and increased respectively, the foliar concentration of all other nutrients decreased between 1993 and 2009, which can be explained by the decrease in ion concentration in solution. These nutritional disorders weakened trees and were probably exacerbated during the 2003 summer drought, after which symptoms of vitality loss progressively appeared. In these N‐saturated ecosystems, the N cycle was disrupted by this health decline, which increased NO3? leaching reinforcing soil acidification and risk of aluminum (Al) toxicity. 相似文献
9.
In this study, we provide a detailed analysis of tree growth and water status in relation to climate of three major species
of forest trees in lower regions of Bavaria, Southern Germany: Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and common oak (Quercus robur). Tree-ring chronologies and latewood δ13C were used to derive measures for drought reaction across trees of different dimensions: growth reduction associated with
drought years, long-term growth/climate relations and stomatal control on photosynthesis. For Scots pine, growth/climate relations
indicated a stronger limitation of radial growth by high summer temperatures and low summer precipitation in smaller trees
in contrast to larger trees. This is corroborated by a stronger stomatal control on photosynthesis for smaller pine trees
under average conditions. In dry years, however, larger pine trees exhibited stronger growth reductions. For Norway spruce,
a significantly stronger correlation of tree-ring width with summer temperatures and summer precipitation was found for larger
trees. Additionally, for Norway spruce there is evidence for a change in competition mode from size-asymmetric competition
under conditions with sufficient soil water supply to a more size-symmetric competition under dry conditions. Smaller oak
trees showed a weaker stomatal control on photosynthesis under both dry and average conditions, which is also reflected by
a significantly faster recovery of tree-ring growth after extreme drought events in smaller oak trees. The observed patterns
are discussed in the context of the limitation-caused matter partitioning hypothesis and possible species-specific ontogenetic
modifications. 相似文献
10.
Summary Potted young Norway spruce trees were exposed to different concentrations of the air pollutants ozone, sulphur dioxide and nitrogen dioxide under completely controlled environmental conditions. After the treatment, the potted trees were kept outdoors. Measurements of the maximum photosynthetic capacity (A2500) were performed with current-year and 1-year-old needles during and after exposure of the trees. In trees fumigated with nitrogen oxides no damage was found at the concentrations used, and the trees' ability to fix carbon dioxide was increased. Using SO2, a rapid and marked decrease in A2500 was obtained within the first days of the experiment. This decrease did not continue further, but was reversed upon cessation of the fumigation. However, a clear dose-dependent decrease in A2500 occurred when trees were fumigated continuously with an ozone concentration of 450 nl l–1 or more. The effect of ozone was not reversible, but continued during post-culture of the trees. 相似文献