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.     

Cystein und Glutathion in gesunden und SO2-geschädigten Fichtennadeln

Cysteine and glutathione in healthy and SO₂ damaged spruce needles. SO₂ damaged and healthy spruce needles were analysed for water soluble SH groups. Total SH content was mainly due to glutathione with some cysteine. Increased cysteine content was found only in old needles. Total content of SH groups fluctuates seasonally in the same way in both healthy and damaged needles. SO₂ damaged needles, however, always contain more SH-groups than healthy needles except immediately after flushing.     

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.     

Injury to Eastern White Pine by Sulfurdioxide and Ozone Alone and in Mixtures

Clones of eastera white pine (Pinus strobus) selected for their sensitivity to sulfur dioxide (SO₂) were fumigated in a controlled environment chamber. Sulfur dioxide alone and in combination with ozone (O₃) at concentration 5 parts per hundred million (pphm) of air by volume of each gas for independent 2-hr exposures was toxic to new needles. Severest injury resulted from a discontinuous fumigation with 5 pphm O₃ and 5 pphm SO₂for 2 hr in separate fumigations, followed 24 hr later by a 2-hr exposure to a mixture of these gases, each at 5 pphm. The rapidity of lesion development and total injury to new needles were less following a single 2-hr fumigation with an O₃-SO₂mixture than when a single 2-hr fumigation with SO₂alone was used. Ozone and SO₂reacted to reduce injury. These plants were not injured by O₃used alone. New needles receiving only filtered air or new needles on resistant plants were not visibly affected by any treatment. Acute injury induced by the O₃-SO₂mixture developed differently from injury induced by SO₂alone.     

S-Lokalisation in SO2-begasten Fichtennadeln

Localisation of sulphur in spruce needles treated with SO₂. After exposure to SO₂ the tips of spruce needles arc richer in sulphur compounds than the bases. The accumulation of sulphur compounds results mainly in an increased content of inorganic sulphur. The analytical results explain the local occurrence of injuries at the needle tips.     

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.     

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.     

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.     

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.     

Der Nachweis winterlicher SO2-Immissionen an jungen Fichten Ein Vergleich dreier Methoden

The detection of winter SO₂ pollution effects on young spruce. A comparison of three methods. The suitability, sensitivity and tediousness of three methods (turbidity-test, peroxidase activity, buffering capacity) were compared for detecting the effect of SO₂ pollution in winter on spruce seedlings. Buffering capacity failed to detect a difference between controls and fumigated trees. Turbidity test and peroxidase activity yielded statistically significant differences. The turbidity test is less tedious but also less sensitive than peroxidase activity and its use is restricted to conifers.     

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.

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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.

     

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

Causes and criteria of resistance to air pollution in Norway spruce. 1. Morphological and anatomical resistance. Pollution resistance of selected visibly resistant clones is not due to environmental causes or to length of the growing season. Between the resistant and other clones there are significant differences in morphology and anatomy of the needles. The average length, width and weight of the needles of resistant spruce grafts arc greater than those of none resistant. The resistant grafts have more stomata and, at least in winter, lower permeability of needle tissue to gases.     

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.     

Fluorometrische Beurteilung der relativen SO2-Resistenz von Fichte (Picea abies [L.] Karst.) anhand niedermolekularer Metabolite aus Nadelextrakten

Fluorometric examination of the relative insistence to SO₂ of Norway spruce (Picea abies [L.] karst.) using low molecular metabolites from needle extracts. Relatively resistant and “normal” spruce grafts were shown by a fluorometric method to possess different concentrations of fluorescent needle metabolites. The described method could be useful in verifying resistence qualities of Norway spruce.     

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.     

Physiological response of irrigated and non-irrigated Norway spruce trees as a consequence of drought in field conditions

Physiological reactions of 25-year-old Norway spruce (Picea abies (L.) Karst.) trees to drought were examined during 2009 vegetation period. During the second half of summer, the decrease in soil water content was observed and irrigation was applied to a group of spruce trees, while the second group was treated under natural soil drought. The response to water deficit was recorded at the level of leaf water potential (Ψ_L). However, it appears that Ψ_L plays minor role in early stomata regulation of Norway spruce as CO₂ assimilation rate (P _N) and stomatal conductance (g _S) were reduced already before water potential decrease. Leaf water potential decreased significantly only in case when soil water content was low in the long run and when transpiration losses were simultaneously relatively high. Almost complete stomatal closure even of the irrigated trees was caused by the increase in the vapour pressure deficit of the air (D) above the value of approximately 1.5?kPa. Low values of D were accompanied by partial stomata opening of drought-treated trees. In non-irrigated spruce trees, the values of P _N decreased by 35–55% in comparison with irrigated trees. No drought-induced significant changes were found either in chlorophyll and carotenoid concentration (chl a?+?b, car) or in maximal photochemical efficiency of photosystem II (F _v/F _m). High rates of sap flow (F) did not always lead to stomatal closure during midday. It?appears that high transpiration rates do not control stomatal response to D.     

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.     

Einfluß von SO2 und HF auf freie Aminosäuren der Fichte (Picea abies [L.] Karsten)

The influence of SO₂ and HF on free amino acids of spruce . The influence of the air pollutants SO₂ and HF on composition and amount of free amino acids was investigated. Distinct differences in the pattern of amino acids are caused, particularly in glutaminic acid and compounds based on it.     

Water relations and morphological development of bare-root jack pine and white spruce seedlings: seedling establishment on a boreal cut-over site

Bare-root jack pine (Pinus banksiana Lamb.) and white spruce (Picea glauca (Moench) Voss) seedlings were planted on a boreal cut-over site and subsequent growth and seedling water relation patterns were monitored over the first growing season. Comparison of morphological development between white spruce and jack pine showed jack pine seedlings had greater new root development and a lower new shoot/new root ratio, while white spruce seedlings had greater new shoot development. Seasonal water relation patterns showed white spruce seedlings to have a greater decrease in xylem pressure potential (_x) per unit increase in transpirational flux density in comparison to jack pine seedlings. These results suggest that the greater resistance to water flow through the soil-plant-atmosphere continuum in white spruce seedlings compared to jack pine seedlings may be due to the relative lack of new root development in white spruce. Stomatal response of the seedlings showed that as absolute humidity deficit between the needles and air (AHD) increased, needle conductance (gwv) decreased in both species, but at low AHD levels white spruce had gwv approximately 35% higher than jack pine. For white spruce seedlings, gwv decreased as _x became more negative in a predictable curvilinear manner, while gwv of jack pine seedlings responded to _x with a threshold closure phenomenon at approximately - 1.75 MPa. Tissue water potential components for jack pine and white spruce seedlings at the beginning and end of the growing season showed jack pine to reach turgor loss at 76% relative water content while white spruce reached turgor loss at 88% relative water content. White spruce seedlings showed osmotic adjustment over the growing season, with an osmotic potential at turgor loss of - 1.27 MPa and - 1.92 MPa at the beginning and end of the growing season, respectively. Jack pine did not show any osmotic adjustment over the growing season. The implication of morphological development on water relation patterns are discussed with reference to successful seedling establishment.