During two vegetation periods, young clonal spruce trees (Picea abies (L.) Karst.) with sufficient and poor magnesium (Mg) supply were exposed in the environmental chambers of the GSF phytotron to three levels of ozone (daily means: 18-22, 88-130, and 135-190 microg m(-3); 10% reduction at night). Previous year's needles were examined at 4-week intervals with respect to their contents of Mg, Ca, K, Mn, N, P, and chlorophyll (Chl), various parameters of Chl fluorescence, and the stability of the isolated light-harvesting Chl-a/b-protein complex LHC II. The needles of the two nutrition variants contained more than 0.53 or less than 0.27mg Mg g(-1) needle dry matter, respectively. The ratio of variable to maximal Chl-a fluorescence of the dark-adapted needles, Fv/Fm, and the photoinhibitory quenching of Fv after light treatment, SVi.v, were affected by the Mg content of the needles rather than the ozone levels. Changes of the Chl content and the behavior of the LHC II allowed differentiating between a slow process of needle yellowing occurring under Mg deficiency only, and a rapid process of needle yellowing occurring under the combined action of Mg deficiency and ozone pollution. Only the rapid yellowing process was accompanied by destabilization of the LHC II, and the degree of destabilization was correlated with the ozone concentration present in the days before sampling. The results are consistent with observations obtained at a research site in the Central Black Forest (J Plant Physiol 161 (2004) 423).

Spring barley ( Hordeum vulgare L. cv. Scarlett) was grown at two CO2 levels (400 vs. 700 ppm) combined with two ozone regimes (ambient vs. double ambient) in climate chambers for four weeks, beginning at seedling emergence. Elevated CO2 concentration significantly increased aboveground biomass, root biomass, and tiller number, whereas double ambient ozone significantly decreased these parameters. These ozone-induced reductions in growth parameters were strongly overridden by 700 ppm CO2. The elevated CO2 level increased C : N ratio of the leaf tissue and leaf starch content but decreased leaf protein levels. Exposure to double ambient ozone did not affect protein content and C : N ratio but dramatically increased leaf starch levels at 700 ppm CO2. Resistance against Drechslera teres (Sacc.) Shoemaker was increased in leaves grown at double ambient ozone but was less obvious at 700 ppm than at 400 ppm CO2. Constitutive activities of beta-1,3-glucanase and chitinase were significantly higher in leaves grown at double ambient ozone compared to ambient ozone levels. The sum of methanol-soluble and alkali-released cell wall-bound aromatic metabolites (i.e., C-glycosylflavones and several structurally unidentified metabolites) and lignin contents did not show any treatment-dependent differences.

The S-adenosyl-L-methionine:pinosylvin-O-methyltransferase (PMT) gene was sequenced from Scots pine (Pinus sylvestris). The open reading frame is arranged in two exons spaced by one 102-bp intron. Promoter regulatory elements such as two "CAAT" boxes and one "TATA" box were identified. Several cis-regulatory elements were recognized: stress-responsive elements (Myb-responsive elements) as well as G, H, and GC boxes. Moreover, elicitor-responsive elements (W boxes) and a sequence resembling the simian virus 40 enhancer core were found. In phloem and needles of control trees, the transcripts of stilbene synthase (STS) and PMT were hardly detectable. Increased ozone fumigation up to 0.3 microL L(-1) enhanced the transcript level of STS and PMT in needles but not in healthy phloem. Wounding, e.g. mock inoculation, of stem-phloem was characterized by a transient increase in STS and PMT transcripts, which was more pronounced in the case of fungal inoculation. Combination of fungal-challenge or mock treatment with ozone resulted in a positive interaction at 0.3 microL L(-1). Scots pine stilbene formation appeared to be induced via STS and PMT gene expression upon ozone and fungal stress as well as wounding. The broad stress-responsiveness is in agreement with the range of various cis-acting elements detected in the STS and PMT promoters.

Stem cellulose of bean plants (Vicia faba) grown under controlled conditions exhibits inverse linear carbon–isotope reactions to changes in both relative humidity (RH) and temperature (T), readily mappable as a planar δ13C response surface in RH–T space. The analogous response surface for annual late-wood cellulose δ13C from a field calibration using fir trees (Abies alba) in the Black Forest, southern Germany, also supports resolution of independent δ-RH and δ-T effects. The response of cellulose δ13C to RH and T derived from this new calibration differs markedly from estimates based on univariate linear regression analysis: The sensitivity of δ13C to RH is stronger than that inferred previously (c. −0.17‰/% vs. −0.12‰/%, respectively), whereas the δ-T coefficient is weaker and reversed in sign (c. −0.15‰/K vs. +0.36‰/K). This new perspective on the coupled influence of moisture and temperature changes on tree-ring cellulose δ13C helps to unify divergent observations about carbon–isotope signals in trees, especially the broad range of apparent δ-T relations obtained in calibration studies, which are often used as paleoclimate transfer functions. Although this highlights the large potential uncertainties surrounding paleoclimate reconstruction based solely on δ13C data, coupling of the carbon–isotope response–surface approach with equivalent response surfaces for hydrogen or oxygen isotopes may afford new opportunities for investigating the nature of past climate variability and change from tree-ring sequences.

Tree damage in the field is judged primarily by visual inspection (Forschungsbeirat Waldschäden 1989; Chappelka and Chevone 1992) using needle and leaf discoloration, premature abscission and crown transparency as the principle and rather nonspecific symptoms. A diagnostic field guide is available for distinguishing "novel" decline symptoms from known mineral deficiencies and frost or insect damage (Hartmann et al. 1988).

Two clones of 5-yr-old Norway spruce (Picea abies [L.] Karst.) were exposed to two atmospheric concentrations of CO 2 (350 and 750 μmol mol -1 ) and of O 3 (20 and 75 nmol mol -1 ) in a phytotron at the GSF-Forschungszentrum (Munich) over the course of a single season (April-October). The phytotron was programmed to recreate an artificial climate similar to that at a high elevation site in the Inner Bavarian forest, and trees were grown in 40 1 containers of soil (pH 3.5) fertilized to achieve two levels of potassium nutrition ; well fertilized and K-deficient. Foliar nutrient analyses performed at the beginning of the exposure indicated that the fertilization programmes achieved their goal without significantly altering the levels of other nutrients or the soil pH. At the beginning of the fumigation, foliar K concentrations were 7-9 mg g -1 d. wt for well fertilized trees and 4-5 mg g -1 d. wt for trees receiving no supplemental K. Over the course of the season, differences between K treatments intensified so that by the end of the experiment there was a five to sixfold difference between foliar K concentrations. This was associated with slight, but significant (P < 0.05), decreases in S and Zn (and of Cu in the 1989 needle year age class) and higher levels of C, N and Mg in K-deficient trees. Foliar N concentrations were low for all trees (9-15 mg g -1 needle d. wt) but were similar to levels found in the field. Elevated O 3 was found to decrease significantly the C (P < 0.05) and N (P < 0.001) content of both current-year (1989) and previous-year (1988) needles independent of CO 2 concentration, but apart from some minor changes in the concentrations of Cu and Mn in the current-year needles no other effects of the pollutant on plant nutrient status were found. In contrast, CO 2 enrichment resulted in significantly (P < 0.01) lower concentrations of K and P (effects on Mg were also on the borderlines of statistical significance) in current-year needles, but there was no influence on the nutrient composition of the previous-year needles (although effects on N were on the borderlines of statistical significance). CO 2 enrichment also increased (P < 0.05) the C :N ratio of both current-year and previous-year needles. One factor contributing to the decline in foliar K at elevated CO 2 appeared to be a marked increase (25-30%) in the rate at which cations were leached from the canopy by repeated simulated acid mist (pH 4.0) events, and this effect occurred independently of the O 3 concentration. The information presented will aid the interpretation of parallel studies examining the effects of elevated CO 2 and/or O 3 on seasonal changes in photosynthesis, non-structural carbohydrate content, antioxidants, tree growth and water use efficiency, and sheds further light on the growing scepticism concerning the role of O 3 in the development of Mg and K-deficiency symptoms characteristic of certain types of forest decline in central Europe.

ABSTRACTTwo clones of 5‐year‐old Norway spruce [Picea abies (L.) Karst.] were exposed to two atmospheric concentrations of CO2 (350 and 750 μmol mol−1) and O3 (20 and 75nmolmol−1) in a phytotron at the GSF‐Forschung‐szentrum (Munich) over the course of a single season (April to October). The phytotron was programmed to recreate an artificial climate similar to that at a high elevation site in the Inner Bavarian Forest, and trees were grown in large containers of forest soil fertilized to achieve contrasting levels of potassium nutrition, designated well‐fertilized or K‐deficient. Measurements of the rate of net CO2 assimilation were made on individual needle year age classes over the course of the season, chlorophyll fluorescence kinetics were recorded after approximately 23 weeks, and seasonal changes in non‐structural carbohydrate composition of the current year's foliage were monitored. Ozone was found to have contrasting effects on the rate of net CO2 assimilation in different needle age classes. After c. 5 months of fumigation, elevated O3 increased (by 33%) the rate of photosynthesis in the current year's needles. However, O3 depressed (by 30%) the photo‐synthetic rate of the previous year's needles throughout the period of exposure. Chlorophyll fluorescence measurements indicated that changes in photosystem II electron transport played no significant role in the effects of O3 on photosynthesis. The reasons for the contrasting effects of O3 on needles of different ages are discussed in the light of other recent findings. Although O3 enhanced the rate at which CO2 was fixed in the current year's foliage, this was not reflected in increases in the non‐structural carbohydrate content of the needles. The transfer of ambient CO2‐grown trees to a CO2‐enriched atmosphere resulted in marked stimulation in the photosynthetic rate of current and previous year's foliage. However, following expansion of the current year's growth, the photosynthetic rate of the previous year's foliage declined. The extent of photosynthetic adjustment in response to prolonged exposure to elevated CO2 depended upon the clone, providing evidence of intraspecific variation in the long‐term response of photosynthesis to elevated CO2. The increase in photosynthesis induced by CO2 enrichment was associated with increased foliar concentrations of glucose, fructose and starch (but no change in sucrose) in the new growth. CO2 enrichment significantly enhanced the photosynthetic rate of K‐deficient needles, but there was a strong CO2soil interaction in the current year's needles, indicating that the long‐term response of trees to a high CO2 environment may depend on soil fertility. Although the rate of photosynthesis and non‐structural carbohydrate content of the new needles were increased in O3‐treated plants grown at higher levels of CO2, there was no evidence that elevated CO2 provided additional protection against O3 damage. Simultaneous exposure to elevated O3 modified the effects of elevated CO2 on needle photosynthesis and non‐structural carbohydrate content, emphasizing the need to take into account not only soil nutrient status but also the impact of concurrent increases in photochemical oxidant pollution in any serious consideration of the effects of climate change on plant production.

In order to find probable causes for damages on Norway spruce in the calcareous Alps, soil and nutritional investigations were conducted in Norway spruce stands located along one elevation profile at the Wank mountain Bavarian Alps. The results indicate that the anthropogenic deposition is very low in this area, and that does not impose a burden on the Norway spruce. The nutritional supply of K, Mg, and Ca is optimal. Due to the low water storing capacity, the soil frequently dries out in summer, and the trees suffer from nitrogen and phosphorus deficiency. The needle loss correlates along the elevation profile with P-contents both in the needles and in the soil. Therefore, a causal relation is assumed between needle loss and P deficiencies. As P is stored predominantly in the humus, the amount of the humus plays an important role for the P-supply. The humus at the Wank has been affected decisively by the exploitation history of the area (grazing, game, litter use).

Am Wank in den Kalkalpen wurden entlang eines Höhenprofils boden- und ernährungskundliche Untersuchungen in Fichtenbeständen durchgeführt, um mögliche Ursachen für die Schäden der Fichten auf diesem Standort aufzufinden.

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.

This paper summarizes and evaluates the main findings of 14 preceding papers related to the joint 14-month tree-exposure experiment carried out by the 'Munich Working Party on Air Pollution' at the GSF, Munich, FRG, from July 1986 to September 1987. The experiment tested the hypothesis that an interaction of ozone/acid mist/soil/extreme climatic conditions is the cause of decline of Norway spruce (Picea abies (L.) Karst.) at higher altitudes of the Inner Bavarian Forest. The main findings of the individual studies are presented and their implications for the hypothesis are discussed. Clear effects of soil and genetic factors (differences between clones), for example on growth and frost resistance were found. Treatment with O(3)/acid mist was shown to have effects on plant biochemistry, physiology, histology/ cytology, and growth. The wide scattering of these effects, and the lack of a consistent pattern of response across all clones does not permits a firm conclusion on the validity of the experimental hypothesis. These effects were not confounded by the nutrient stresses imposed during the initial exposure period and were not found to be cumulative during repeated treatments, as was proposed by the hypothesis. It is concluded that the experimental evidence does not indicate that ozone/acid mist are major factors to explain the Norway spruce decline on acidic sites at higher altitudes of the Inner Bavarian Forest and probably similar forest areas.

Five clones of 3-year old Norway spruce (Picea abies [L.] Karst), planted in a soil from the Bavarian Forest (pH 4.4) or a soil from the Calcareous Bavarian Alps (pH 6.9), were exposed for two successive vegetation periods, in closed environmental chambers, to a pollution treatment consisting of acidic mist (pH 3.0) plus ozone levels of 100 microg m(-3) with episodes of 130-360 microg m(-3); control trees were exposed to mist of pH 5.6 and ozone levels of 50 microg m(-3). Climatic and pollution protocols followed the diurnal and seasonal pattern characteristic for the Inner Bavarian Forest in Southern Germany, an area affected by the new-type forest decline. Biometric parameters were strongly related to clone and soil. Pollution treatment had a limited effect on only a few growth parameters. The stem diameter growth increment of two clones was reduced by pollution treatment in both soils, a third clone was affected in the acidic soil only. Two other clones were not affected at all. Stem volume increment of three clones, calculated as D(2)H, was reduced by pollution treatment in the neutral soil, a fourth clone was affected in the acidic soil only. Bud break was either delayed (two clones) or accelerated (two other clones) by treatment. Depending on soil and clone, needle yellowing was observed in previous years' needles in both treatment and control trees exposed to increased light intensities. The 'spotted' yellowing was not identical to symptoms found in forest decline areas and was most likely a consequence of nutrient deficiencies during the vegetation period preceding the experiment. The results of this experiment are discussed with regard to field observations and forest productivity. The complex pattern of growth responses resulting from interactions between air pollution, soil and genetic factors is considered to reflect different susceptibilities of trees to air pollutants.

Four clones of 3-year-old Norway spruce (Picea abies (L.) Karst.), grown on two soils, were from July 1986 to September 1987 exposed to ozone fumigation (50 μg m−3 as a control, 100 μg m−3 plus peaks between 130 and 360 μg m−3 as treatment) and acid mist of pH 3·0 (versus mist pH 5·6 in the control). Climatic conditions, identical for both control and treatment, followed a diurnal and seasonal pattern characteristic of medium high altitudes of the Bavarian Forest, an area affected by the new-type forest decline. Gas-exchange measurements were carried out on the plants from December 1986 until the end of the 14-month's exposure using a series of climate-controlled minicuvettes. ANOVA of the four clones investigated towards the end of the experiment gave hints of a treatment-related depression of the photosynthetic capacity of the previous year's needles (age-class 1986). Within this age-class only one of the clones (11) showed a significant treatment effect, indicating an age-class dependence and a genetic influence of the treatment-related depression of the photosynthetic capacity. The current year's flush was not impaired through the ozone and acid mist exposure. Analysis also revealed clear effects of soil, clone and needle age on photosynthetic parameters.

Several species of legumes and varieties of lupins were examined for their heavy metal content in the seeds. Atomic absorption spectrometry was the main analytical tool. Validity and reproducibility of the results was checked by analyzing the same materials at two different laboratories performing the same technique. Additionally, inductively coupled plasma emission spectroscopy was applied. In grains of Lupinus mutabilis which constitute a traditional food in Andean populations, the following contents of heavy metals were determined: 0.10-0.25 microgram/g Cd; 0.5-1.6 microgram/g Pb; 0.10-0.15 microgram/g Hg. Seeds of other legumes contained 0.05-0.35 microgram/g Cd; 0.1-0.2 microgram/g Pb; 0.01-0.04 microgram/g Hg. The high lead content of lupins is easily reduced to one tenth by traditional extraction with boiling water. The mercury content, too, is decreased by this technique. The high manganese content of 1 300-1,400 micrograms/g of Lupinus albus compared to other legumes (25-37 micrograms/g) seems to be characteristic for this species and may be of nutritional significance. The comparison of the heavy metal contents of legume seeds of different origin and variety indicates a complex pattern of environmental and genetic factors that contribute to the specific metal contents of individual harvests. On the level of varieties the environmental factors (climate, soil, geology, agricultural techniques) seem to exhibit more important influences on the specific accumulation of heavy metals than genetic factors. In contrast, on the level of species or genera, the accumulation of heavy metals seems to be dominated by genetic factors rather than by environmental influences.

Die Klima- und Schadstoffbedingungen während des ersten Langzeitexperiments in den neuen Expositionskammern der GSF werden beschrieben. Mit diesem fünf Monate dauernden Versuch wurde zugleich die Leistungsfähigkeit der Kammern unter realistischen, jahreszeitlich unterschiedlichen Versuchsbedingungen ermittelt. In einer faktoriellen Versuchsanordnung mit 16 Pflanzengruppen von je sechs vierjährigen Fichtenstecklingen wurde die Wirkung folgender Faktoren untersucht: Normales Winterklima im Vergleich zu einer extremen Frostperiode; niedrige gegenüber erhöhten Ozonkonzentrationen; Nebel von pH 5,6 im Vergleich zu pH 3; Magnesium-/Calcium-gedüngte gegenüber ungedüngten Pflanzen. Die Klima- und Schadstoffbedingungen orientierten sich an Meßwerten aus den Hochlagen des Bayerischen Waldes, die von neuartigen Waldschäden betroffen sind. Die technische Kammercharakteristik und die Reproduzierbarkeit der Betriebsbedingungen werden bewertet.

Monthly depositions of cadmium were collected by a modified Bergerhoff method and measured by AAS during a 3-year period in rural areas of the Pfalz and in an industrial area of the Ruhr district. Another one year period included measurements in rural areas of southern Bavaria and on a Dutch island. The log-normally distributed deposition rates of cadmium at the rural areas in southern Germany amounted to only 20% of those of the industrial district. The depositions on the Dutch island were twice as high as the depositions on the rural areas of southern Germany. The monthly cadmium deposition rates show only little periodical fluctuation during the year and scatter around more or less constant median values of 25 and 120 μg · m−2 · month−1 at the rural and industrial areas, respectively. When open air mass cultures of algae were taken as an agricultural model, the organisms, depending on their growth rate, accumulated 0.4–4.0 ppm of cadmium (dry matter based). The course of the cadmium accumulation reflects the deposition rate of the area where the algae were grown. No growth depression of the algae due to cadmium can be observed under the given deposition rates.

A simple rocking device (10–17 oscillations min-1) using open plastic trays (0·05–0·5 m2) was constructed and tested for experimental cultures of microalgae. The culture apparatus was useful for comparative productivity measurements. Optimum depth for the algae cultures was 2–3 cm. Partial cover of the rocking tray cultures by translucent polyacrylate sheets simulated tropical temperature conditions in the cultures under the climatic conditions of Germany. The rocking trays were successfully applied to screening for algae of high yield during several years under the climatic conditions of tropical Thailand. If the nutrient supply is saturating, the yields of this culture apparatus correspond well to those of technical mass cultures of microalgae. Additional informationNotes on contributorsH.D. Payer This department and research centre has been partly transferred to KFA Jülich, P.O. Box 1913, 517 Jülich, Federal Republic of Germany. Anukool Polsiri This department and research centre has been partly transferred to KFA Jülich, P.O. Box 1913, 517 Jülich, Federal Republic of Germany.