A new type of forest decline in Germany.

There is much concern about the state of West Germany's large forests which are threatened by an unprecedented decline. Research into its causes no longer focuses on acid rain, but on a possible interaction of increased ozone concentrations, acid mist and climatic factors

Simultaneous exposure of forest trees to pollutants and climatic stress.

This paper describes a facility designed to simultaneously generate complex climatic and pollutant conditions for research into the effects of climate and air pollution on plants. The system, commissioned in 1985, consists of a set of 4 environmental chambers which are each equipped with four identical subchambers. The 4 subchambers are subjected to identical climatic conditions, but are equipped with independent gas supplies. The chambers are designed to operate within a temperature range of -20 to +40°C at a relative humidity of 20 to 95% with an illumination system providing high light intensities at a spectrum very close to sunlight. A computer controlled fumigation system allows the injection of various gases singly and in combination at concentrations between 0.005 to 1,000 ppm (SO2, NO(x), O3, CO2, PAN).This paper describes a facility designed simultaneously to generate complex climatic and pollutant conditions for research into the effects of climate and air pollution on plants. The system consists of a set of 4 environmental chambers which are each equipped with four identical subchambers. These 4 subchambers are subjected to identical climatic conditions, but are equipped with independent gas supplies. The chambers are designed to operate within a temperature range of minus 20 to plus 40 degree C at a relative humidity of 20 to 95% with an illumination system providing high light intensities at a spectrum very close to sunlight. A computer controlled fumigation system allows the injection of various gases singly and in combination at concentrations between 0. 005 to 1,000 ppm (SO//2, NO//X, O//3, CO//2, PAN)

Effects of Ozone, Acid Mist and Soil Characteristics on Clonal Norway Spruce (Picea abies (L.) Karst.) - Overall Results and Conclusions of the Joint 14 Months Tree Exposure Experiment in Closed Chambers.

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 O3/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

Air pollution and plant metabolism.

The 20 contributions examine mechanisms by which (potentially) harmful atmospheric gases and their aqueous products can exert an influence on living plant cells at the ultrastructural, biochemical and physiological levels. With a general understanding of metabolic changes, predictive models should be able to assess the relative consequences of atmospheric pollutants upon plants. Papers include discussion of: deposition, uptake and residence of pollutants; carbon gain, allocation and growth as affected by air pollution; interactions between air pollutants and both water stress and cold stress; air pollution effects on plant pathogens; effects of pollutants on mycorrhizae; and effects on host plant/insect relationships

The Liphook forest fumigation project 3rd report First fumigation phase

SIGLEAvailable from British Library Document Supply Centre- DSC:7761.0382(ESTD-L--0052/R89) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Effects of Low-Level Long-Term Ozone Fumigation and Acid Mist on Photosynthesis and Stomata of Clonal Norway Spruce (Picea abies (L.) Karst.).

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