Tropospheric ozone in the pre-alpine and alpine regions

Sandroni, S.; Bacci, P.; Boffa, G.; Pellegrini, U.; Ventura, A.

doi:10.1016/0048-9697(94)90354-9

Cited by 37 publications

(14 citation statements)

References 23 publications

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“…4 displays maps related to a 4-week per- iod in the month of July. In these maps, the assessed concentration values follow altitude and therefore maintain the orographic outline of the valley, thus confirming the findings discussed in the literature [13,18,19,20,21,22]: ozone concentrations follow a vertical gradient which increases with increasing altitude.…”

Section: Resultssupporting

confidence: 88%

Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers

Mazzali¹,

Angelino

Gerosa

et al. 2002

The Scientific World JOURNAL

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Passive samplers (diffusion tubes with organic reagent, produced by Passam of Switzerland) were used in a sampling campaign for the detection of weekly mean ozone concentrations in 15 sites over a domain of 80 × × × × 40 km on the southern side of the European Alps from May to August 1998. The area is characterized by vast natural terrain of complex topography, with conifer and broadleaf forests. It is difficult to access and monitor air quality there with continuous analysers. By applying geostatistical techniques (ordinary kriging), and correcting the interpolated ozone concentrations according to the altitude of each single grid cell (2 × × × × 2 km), maps of weekly ozone concentrations were produced. The weekly ozone data were used to assess daily and hourly data by means of an iterative procedure based on a functional dependence of ozone concentrations both on altitude and on the time of day. This allowed the estimation of values with an exposure index such as AOT40 (accumulated exposure over the threshold of 40 ppb) in all 800 cells of the domain. This also allowed the mapping of risk assessment related to the effects of ozone on the regional forest vegetation. Results obtained show values that exceed the exposure standards adopted in the Kuopio protocol (1996). Excess exposure values also match values calculated over a wider territorial domain by using hourly data on ozone concentration derived from continuous automatic analysers.KEY WORDS: ozone, risk assessment, Alps, forests, passive samplers, exposure indices, AOT40, geostatistics DOMAINS: atmospheric systems, ecosystems and communities, environmental toxicology, environmental technology, environmental management and policy, ecosystems management, environmental monitoring, environmental modelling, information management Mazzali et al.: Ozone Risk Assessment by Passive Sampling TheScientificWorldJOURNAL (2002) 2, 1023-1035 1024 INTRODUCTIONThe growing stress of high ozone levels in alpine forest ecosystems faces us with the need to perform risk assessment for specific receptors to allow for the protection of the ecological, economic, and aesthetic values of vegetation. During the assessment of dose-response relationship of vegetation to ozone exposure, investigators concentrated on the use of indices to quantify the exposure. Several studies have dealt with both definition and assessment of these indices, taking into account the most harmful pollution levels for vegetation [1,2]. The most frequently used exposure indices attribute different weights to high and low ozone concentrations; these indices include SUM x (sum of the hourly concentrations beyond the x threshold), AOT x (sum of the differences between hourly concentrations and the x threshold), W y (sum of the hourly concentrations weighted by means of sigma functions indicated by the value of y), and AL y (sum of the hourly concentrations weighted by means of allometric functions indicated by the value of y) [3].According to some indices, literature supplies potential damage thresholds (crit...

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Section: Resultssupporting

confidence: 88%

Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers

Mazzali¹,

Angelino

Gerosa

et al. 2002

The Scientific World JOURNAL

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“…The high altitude position of this station means that there is no reduction at night of the ozone produced or transported during the day. A similar phenomenon has already been observed in the Alps (Sandroni et al 1994). It confirms the existence of a pollution plume originating from the neighbouring urban area.…”

Section: Discussionsupporting

confidence: 80%

Physiological study of declining Pinus cembra (L.) trees in southern France

Dalstein¹,

Torti

Thiec

et al. 2002

Trees

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Pinus cembra (L.) trees growing at an elevation of 1,800 m in the Mercantour Alps National Park in southern France have shown various degrees of damage (yellowing and needle loss) since the early 1980s. Two stands were selected, one populated by healthy and the other by damaged trees, and 1-year-old needles were analysed. The needles of the declining trees displayed chlorotic mottled patterns associated with a significantly lower level of total chlorophyll compared to healthy trees. Measurements of gas exchange showed a lower photosynthetic rate linked to a lower activity of ribulose bisphosphate carboxylase and a higher stomatal conductance in needles of declining trees compared to healthy trees. In contrast, phosphoenolpyruvate carboxylase activity was found to be higher in declining tree needles, reaching twice the level measured in healthy tree needles. A significant oxidative stress was also observed in the needles which presented a 68% higher malondialdehyde content than healthy tree needles. The atmospheric concentration of ozone was quite high (40 nl·l -1 , monthly mean in summer) in both stands but preliminary results based on stomatal conductance and ozone concentration measurements suggested a higher ozone flux in needles of declining trees. Ozone is thus suspected as a contributing factor in the observed decline of Pinus cembra trees.

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“…In comparison, mountain areas above 1600 m above sea level have also natural stratospheric ozone intrusions (Reiter, Sladkovic & Kanter, 1987). Intermediate altitudes {c. 2000 m above sea level) are suffering nowadays from increasing anthropogenic ozone loads (Staehelin et al 1993), even more than do high altitudes (Sandroni et al 1994).…”

Section: Ozone Effects On Carbohydrates In Beechmentioning

confidence: 99%

Effects of ambient ozone concentrations on contents of non‐structural carbohydrates in young Picea abies and Fagus sylvatica

Lux¹,

Leonardi²,

Müller

et al. 1997

New Phytologist

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SUMMARYYoung spruce (Picea abies [L.] Karst; 2-yr) and beech trees {Fagus sylvatica L.; current-year atid 1-yr-old seedlings) were grown under field conditions at a rural site near the citi,-of Base! (Schonenbuch; 400 m above sea level) and 2-yr-old spruce trees at an elevated montainous site (Wengernalp; 1890 m ahove sea level). The plants were exposed in open-top-chambers (OTC) either to charcoal-filtered air or ambient air with ozone being the predominant air pollutant at both sites. The exposures lasted up to 1 yr. At the end of the growth period the plants were harvested and the pool sizes of the major non-structural carbohydrates were determined. Exposure to ambient air compared witb filtered air controls caused an increase of glucose, fructose, pinitol, starch and, in some cases, sucrose in needles whereas carbohydrate contents in roots and twigs of spruce were reduced, in particular at Wengernalp. In beecb saplings at Schonenbuch, a significant rise of sucrose and, in some cases, of raffinose, together with a significant reduction of glucose and fructose was observed in buds, lea-\-es, twigs, and roots in ambient air compared with filtered air. In phloem exudates of current year beech seedlings, a 54-160'^',, higher content of carbohydrates was found in ambient air than in filtered air. In roots of the beecb saplings, the amount of soluble carbohydrates increased and starch contents mostly decreased. In general, starch storage in roots and stems was more abundant in beech trees. Spruce, especially at the mountainous site, accumulated high amounts of soluble carbohydrates in needles, in particular glucose.

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Tropospheric ozone in the pre-alpine and alpine regions

Cited by 37 publications

References 23 publications

Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers

Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers

Physiological study of declining Pinus cembra (L.) trees in southern France

Effects of ambient ozone concentrations on contents of non‐structural carbohydrates in young Picea abies and Fagus sylvatica

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