Photosynthese,Transpiration und Spaltöffnungsverhalten verschiedener Holzarten nach Begasung mit SO2

Photosynthesis, transpiration and stomatal response of various species of woody plants exposed to sulfur dioxide. Photosynthesis of Fraxinus excelsior, Piceaabies, Abies alba and Pinus sylvestris declined after 6 and 12 h of fumigation at SO₂ concentrations of 5 and 9mg m^?3. Transpiration also declined, but the maximum depression was only 38%. Stomata began to close after fumigation with ～ 1 mg SO₂m^?3 for 6 h. The diffusion resistance of needles of Pices and Abies increased after fumigation with 9 mg SO₂ for 6h to a peak value of 35–40 scm^?1 and decreased rapidly (Picea) or remained stable (Abies) during the following 30h.     

Experimental investigations of the effects of air pollutants on aphids on coniferous trees

The relative growth, rates of two aphid species feeding on Sitka spruce (Picea sitchensis) and one species on Scots pine (Pinus sylvestris) were measured on two year old trees prefumigated with either ozone (O₃ or nitrogen dioxide (NO₂) and compared with the growth rates of aphids grown, on trees which were exposed to filtered air. All three species showed increased growth rates on trees which were prefumigated with 100ppb NO₂ for periods in excess of 24 hours. However the effects of prefumigation with O₃ were more complex. Only on species,Cinara pilicornis, responded to this treatment and there was a strong interaction between the fumigation treatment and the temperature experienced by the plants during fumigation.     

Einfluß von Schwefeldioxid auf Fichten (Picea abies [L.] Karst.) in verschiedenen Bodensubstraten

Zusammenfassung Drei Jahre alte Fichten wurden nach einer sechsmonatigen Anzuchtsphase in verschiedenen Bodensubstraten sieben Wochen lang mit 140 μg SO₂/m³ begast. Dabei kam ein Begasungsprinzip zur Anwendung, das auch bei Dauerbelastung konstante Gaskonzentrationen, unabh?ngig von sich ?ndernden Depositionsraten gew?hrleistet und Gaswechselmessungen in der geschlossenen Anzuchts- und Begasungskammer erlaubt. Es zeigte sich, da? sowohl n?hrstoffarme B?den als auch eine SO₂-Belastung im Kronenbereich zu Beeintr?chtigungen des Mineralstoffhaushaltes der Pflanzen führen. Insbesondere in den Wurzeln kam es nach einer siebenw?chigen Begasungsdauer zu einer starken Verminderung der Calcium- und Magnesiumgehalte. Auch die Photosyntheseleistung der Pflanzen und der Chlorophyllgehalt der Nadeln wurde durch die kombinierte Belastung mit sauren, n?hrstoffarmen Substraten und Schwefeldioxid st?rker beeintr?chtigt als durch den jeweiligen Einflu? der einzelnen Faktoren.

---

Effects of sulfur dioxide on spruces (Picea abies [L.] Karst.) growing in different soil substrata Exploratory investigations on photosynthesis and mineral nutrient supplies following long-term application of low SO₂ concentrations

Summary Three-year-old spruce plants were grown in different soils for six months and then treated with 140 μg SO₂/m³ for seven weeks. The fumigation system used provides constant gas concentrations during a long-term fumigation period. Information on the combined growth and fumigation chamber is presented. It can be shown that not only nutrient deficiency in the soil but also dry deposition of SO₂ affects the mineral supply of plants. In particular the contents of calcium and magnesium in the roots were drastically reduced after the 7-week exposure period. The combination of acid soil and sulfur dioxide had a greater effect on both net photosynthetic rates of the plants, and chlorophyll contents of the needles as compared with the effect of only one of these stresses.

---

---

Herrn Prof. Dr.W. Liese zum 60. Geburtstag gewidmet.     

Ultrastructure of mesophyll cells of spruce needles exposed to O3 alone and together with SO2

Mesophyll cells of spruce [Picea abies (L.) Karst.] needles fumigated for two months with O₃ alone and together with SO₂ were studied with electron microscope. The observations showed the specific type of injuries for both pollutants, the dependency of severity of injuries both on the concentration of the pollutant and the duration of daily exposure as well as enhanced effects with combined O₃ and SO₂ in the older needles.     

Rasterelektronenmikroskopische Untersuchungen an Stomata von Fichten- und Tannennadeln nach Begasung und saurer Beregnung1

Scanning electron microscopical investigations on stomatal wax plugs of fir and spruce needles after fumigation and acid rain treatment Alterations of stomatal wax plugs of fir and spruce needles have been investigated in order to demonstrate the effects of different air pollutants. After acid rain treatment, and in addition to SO₂ fumigation, heavily melted wax crystals were observed. It is assumed that acid rain causes mainly the changes of the stomatal wax plugs.     

Environmental Effects on Norway Spruce Needle Wax

In spring, tubular wax structures were observed on the needle surfaces of new Norway spruce needles and also on previous-year needles. In young plants, as in mature trees, the fusing and eroding of the wax tubes on needles of increasing age had taken place in relation to their exposure, particularly to wind and precipitation. The quantity of needle wax and certain fractions of the extracted wax differed in mature trees at two field sites and in young clonal plants. No difference in wax quantity and only small differences in wax composition occurred among young plants which had undergone different treatments (fumigation with O³, SO², ambient air, filtered air, or planting at the sites). Environmental effects on wax structure, wax quantity and the presence of certain compounds in the wax were identified.     

Air pollution and ascorbic acid

Well-lighted plants may contain considerable amounts of ascorbic acid (AA) particularly in their chloroplasts. AA is known to be a strong reductant which fulfils several functions in photosynthesis. AA may also influence detoxification of polluted plants, e.g. by reducing SO₂. AA contents of forest tree species were distinctly decreased by shading, particularly in light demanding species. Continued SO₂ fumigation depressed AA contents long before visible symptoms of injury appeared. AA thus deserves more attention in physiological air pollution research.     

Experimental investigations of the effects of air pollutants on aphids on coniferous trees

Summary The relative growth, rates of two aphid species feeding on Sitka spruce (Picea sitchensis) and one species on Scots pine (Pinus sylvestris) were measured on two year old trees prefumigated with either ozone (O₃ or nitrogen dioxide (NO₂) and compared with the growth rates of aphids grown, on trees which were exposed to filtered air. All three species showed increased growth rates on trees which were prefumigated with 100ppb NO₂ for periods in excess of 24 hours. However the effects of prefumigation with O₃ were more complex. Only on species,Cinara pilicornis, responded to this treatment and there was a strong interaction between the fumigation treatment and the temperature experienced by the plants during fumigation.

---

Experimentelle Untersuchungen der Wirkung von Luftschadstoffen auf Bauml?use an Nadelb?umen

Zusammenfassung Relative Wachstumsraten von zwei Arten von Bauml?usen an Sitkafichte (Picea sitchensis) und von einer an der gemeinen Kiefer (Pinus sylvestris) an 2j?hrigen Pflanzen, die vorher entweder Ozon (O₃) oder Stickstoffdioxyd (NO₂) ausgesetzt worden waren, wurden verglichen mit solchen von Bauml?usen, die auf Wirtspflanzen in gefilterter Luft wuchsen. Allen drei Arten zeigten schnelleres Wachstum an Pflanzen, die vorher über 24 Studen lang einer Konzentration von 100 ppb NO₂ ausgesetzt waren. Vielf?ltiger waren jedoch die Auswirkungen von O₃. Nur eine Art,Cinara pilicornis, reagierte auf diese Behandlung, und es gab eine starke Wechselwirkung zwischen der Begasung als solcher und der Temperatur, der die Pflanzen w?hrend dieser Behandlung ausgesetzt waren.

     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst

Causes and criteria of resistancë to air pollution in Norway spruce. 3. Tolerance of toxic materials (“internal” resistance). Comparing relatively resistant and not resistant Norway spruce clones, an attempt was made to find differences by investigating the relation of needle colour and absorption of sulfur, needle pH-value and buffer capacity, sulphur distribution within several of their needle components and within the total plant, the ratio of organically fixed sulfur to total sulfur content of noedles, and content of sulfhydril groups, protein and chlorophyll of needles. Significant differences were shown only in buffer capacity of unfumigated needles, and in thc propornon of organically fixed sulfur before and after SO₂ fumigation.     

Long lasting effects of O3 and SO2 on the sensitivity to drought in two clones of Picea abies (L.) Karst.

Rooted cuttings of two Picea abies-clones were fumigated with O₃ and O₃+ SO₂ for 12 weeks. After 4 and 16 months without fumigation the treated plants showed much higher sensitivity to drought (expressed in osmotic potential of cell sap and in percent survival) than the untreated ones.     

Der Einfluß einer praxisnahen SO2-Begasung auf das 14CO2-Fixierungsmuster von Buchen (Fagus sylvatica L.)

The influence of a SO₂-fumigation on the ¹⁴CO₂-fixation pattern of beeches (Fagus sylvatica L.) under field conditions. The influence of a fumigation with a low SO₂ concentration on the metabolism of beech leaves (Fagus sylvatica L.) was investigated. Changes due to SO₂ were observed in the sulfur content, the ¹⁴CO₂-uptake and the ¹⁴CO₂-fixation pattern. The use of these parameters for the indication of air pollution effects on plants is discussed.     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst1

Causes and criteria of resistance to air pollution in Norway spruce, Picea abies (L.) Karst. IV. Recovery of injured needles, connections between forms of resistance and summary of results to date. Water potential measurement of resistant clones of Norway spruce treated with SO₂ showed that they recovered better than control clones or were at least not so permanently affected. From a variety of experiments on fumigation, it was concluded that reflexive and “internal” resistance were associated. The results of the series of papers so far are summarised.     

O_3浓度升高对桢楠和闽楠幼苗光合作用、抗氧化能力及生物量的影响

[目的]探讨O_3浓度升高对两种亚热带树木幼苗的影响,并分析其敏感性差异及原因。[方法]本试验以1年生桢楠和闽楠幼苗为材料,采用开顶式气室(OTCs),研究未过滤大气、100 nmol·mol-1(E1)、150 nmol·mol-1(E2)O_3处理对光合作用、抗氧化能力和生物量的影响。[结果]研究表明:(1) O_3熏蒸主要通过非气孔限制因素降低了两树种的净光合速率(Pn)。其中对于桢楠,E2对Pn的不利影响大于E1。而对于闽楠,8月份E2的Pn大于E1,而9月份和10月份小于E1。(2) O_3熏蒸提高了两树种的抗氧化能力,表现为总酚含量和总抗氧化能力随着O_3浓度的升高逐渐升高,而E2的还原型抗坏血酸含量低于E1。(3) O_3熏蒸降低了两树种根、茎、叶及总干质量,及降低了闽楠的根茎比。[结论]O_3熏蒸降低了两树种的光合作用,提高了抗氧化能力,最终减少了生物量。根据Pn和生物量,确定闽楠较桢楠对O_3浓度升高更加敏感。两树种间的O_3敏感性差异与气孔导度和抗氧化物质的背景水平及其对O_3浓度升高的响应有关。     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst.

Causes and critcria of resistance to air pollution in Norway spruce. II. Reflexive resistance . The different reactions of stomata of resistant and “normal” spruce grafts were investigated. Resistant grafts were shown to have a more sensitive reaction by measuring water potentials and by analyzing S content in SO₂ fumigated needles or F contents in grafts exposed to polluted air. Other tcsts involving gas permeability of stomata, clecrrical conductivity of needle cxtracts and watcr content of SO₂ fumigated needles were less effective.     

Application of a polymeric coating can protect coniferous trees from acute pollution injury

SO₂ and NO_x are main primary pollutants which often occur together in Europe. In three experiments small spruce trees were exposed to SO₂ or to SO₂ + NO₂ in controlled environmental conditions. A polymeric coating (spodnam), based on a natural terpenoid compound was applied to half the trees fumigated in each experiment and the influence of this material on the sensitivity to pollutant injury was observed. Picea abies and Picea rubens (Norway and Red spruce) were more sensitive than Picea sitchensis (Sitka spruce) to acute damage from 8000 ppb SO₂ experienced for 12-h periods during dormancy. A single application of 15% (ν/ν) of the polymeric coating substantially decreased the extent of acute injury in all three species. Dormant P. sitchensis fumigated with 250 ppb SO₂ and SO₂ + NO₂ also showed less pollutant injury at the end of a 2-month fumigation when 5% (ν/ν) spodman had been applied. Exposure of coated and uncoated seedlings of P. sitchensis to 400 ppb SO₂ during growth in 8-h and 16-h photoperiods confirmed the strong protective effect of a 15% (ν/ν) application. After 6 weeks in 16-h photoperiods, the coated plants grown in SO₂ had larger dry weights than uncoated plants in SO₂. Spodnam also caused decreases of dry weight which were greater in the 8-h daylength, indicating that growth rate was important in determining the physiological cost of having an additional coating over the foliage. Further analysis of the effects of the coating on plant growth and of its protective function against air pollutants are required to determine whether application would be beneficial in forest areas were large concentrations of gaseous air pollutants occur. The timing, concentration and degree of coverage achieved during application would influence the impact of this material; and the benefit gained would depend on the severity of pollutant damage and on the way in which spodnam effects other factors which influence growth.     

Spruce bark influenced by SO2

Investigations into SO₂ absorption by spruce barks using artificial fumigation have proved that continued immissions of SO₂ alter the properties of bark making them capable of accumulating SO₂ up to amounts never attainable by barks grown in clean air. This can be recognized by the time lapse considering SO₂ absorption and by altered ion exchange as well as buffer capacity. With respect to the availability of the bark extracts for mapping SO₂ immissions in the field it is concluded that both conductance and sulphate content of bark extracts represent an integration covering a considerable preceding period being modified by the actual immissions.     

Der Einfluß von kontinuierlichen,niedrigen SO2-Begasungen auf den Phenolgehalt und die Phenoloxidase-Aktivität in Blättern einiger Waldbaumarten

Influence of continuous fumigation by low levels of SO₂ on the phenolic contents and phenoloxidase activities in leaves of forest trees. Potted clonal trees of Norway spruce, black alder and English birch were continuously exposed to low levels of So₂ in fumigation chambers. The phenolic content of the Norway spruce needles was increased consiberably over the controls months before the trees showed any symptoms of damage to the naked eye. Fumigated black alder had a significant higher phenoloxidase activity in the leaves; but this increase only occurred two weeks before the development of necroses. In English birch neither the phenolic content nor the phenoloxidase activity was changed against the unfumigated controls during the course of the experiment.     

Peroxidase-Aktivität in Fichtennadeln unter Schadgasbelastung im Freiland und in Expositionskammern

Zusammenfassung Die Gesamt-Peroxidase-Aktivit?t in grünen, optisch gesunden Nadeln der Fichte (Picea abies L.) wurde im Freiland am Standort “Postturm” (Forstamt Farchau/Ratzeburg) in Tages- und Langzeitkinetiken und bei kurzfristigen Schadstoffspitzenwerten von SO₂ und Ozon untersucht. Parallel hierzu wurde der Wasserhaushalt der Nadeln, die Klimabedingungen und Lichtintensit?ten erfa?t. Unter kontrollierten Bedingungen erfolgte eine Behandlung mit Einzelschadgasen sowie eine Kombinationsbegasung von SO₂ und NO₂ auf die POD-Aktivit?t in Nadeln eines Fichtenklons. Die Ergebnisse zeigen, da? die POD-Aktivit?t Schwankungen unterworfen ist, jedoch keine signifikanten Aktivit?ts?nderungen in Abh?ngigkeit von der Schadgasbelastung zeigt. Die Untersuchungen führen zu dem Ergebnis, da? die Gesamt-POD-Aktivit?t im überstand des Gewebehomogenats von Fichtennadeln als Indikator für eine Umweltbelastung mit Schadgasen ungeeignet ist, da die Aktivit?t dieses Enzyms von zu vielen Faktoren abh?ngig ist.

---

Activity of peroxidase in spruce needles in presence of gaseous pollutants in the field and under controlled conditions

Summary The activity of soluble peroxidase (POD, EC 1.11.1.7.) in green needles of about 100-year-old trees of Norway spruce (Picea abies L.) at the location “Postturm” near Ratzeburg, Northern Germany, was studied in relation to transitory increased concentrations of gaseous air pollutants (SO₂ up to 260 ppb in winter, and O₃ up to 130 ppb in summer). Significant changes of POD activity in response to pollution could not be observed. POD activity did not show diurnal variation, but seasonal changes, and changes in response to sunlight (sun needles versus shade needles) and in relation to needle age were observed as well as great variation between individual trees. Moreover, seven-year-old cloned spruce trees were exposed to SO₂, O₃ and NO₂ in growth chambers under simulated climatic outdoor conditions. Consistent with the field studies no changes in POD activity in response to the gaseous pollutants could be observed, although the concentrations applied were higher than in the field. It is, therefore, concluded that the activity of soluble POD is not a suitable indicator for the tested gaseous pollutants.

     

Eine einfache Methode zur SO2-Begasung von Fichtenpfropflingen im Labor1

A simple method for SO₂ fumigation of Norway spruce grafts in the laboratory. To investigate the resistance mechanism of Norway spruce to SO₂ a simple fumigation chamber was used. The conditions of fumigation gave the desired range of symptom expression.     

Peroxidase- und Superoxiddismutase-Aktivität sowie Prolingehalte von Fichtennadeln nach Belastung mit O3, SO2 und NO2

In long-term experiments the influence of various combinations of O₃, SO₂ and NO₂ on peroxidase activity, superoxide dismutase activity as well as on proline contents of spruce needles was studied. The reactions of these parameters varied depending on the type of pollution and the needle age. Peroxidase and superoxide dismutase activity were also influenced by Mg and Ca supply of the plants.