Field Surveys of Ozone Symptoms on Spontaneous Vegetation. Limitations and Potentialities of the European Programme (original) (raw)

Field surveys of ozone symptoms in Europe. Problems, reliability and significance for ecosystems

The ICP-Forest program for the monitoring of forest conditions includes the assessment of ozone symptoms in the European forests. This contribute to discussion points out the problems related to the recognition of such symptoms, with a special focus on the difficulties to extend the results obtained in experimental conditions to woody plant species growing in the field. Non specific symptoms (such as reddening, yellowing, early senescence and leaf loss), and the concurrent action of modifying factors (high light, drought, nutrient deficiency, pest attack and fungi) make the recognition elusive. In these cases, the action of ozone cannot be proven or excluded with “ad hoc” experiments. Apparently “good” bioindicators (Rubus sp. Cornus sp. pl., Prunus sp. pl., Viburnum sp. pl. etc.) are not suitable to assess the impact of ozone on vegetation. Symptoms are not necessarily related to the ozone dose taken up by stomata, and don’t are reliable indicator for biomass and productivity losse...

Ozone sensitivity of wild field layer plant species of northern Europe. A review

Plant Ecology (formerly Vegetatio), 2004

The increasing tropospheric ozone (O 3 ) concentration constitutes a potential threat to nature. Plants are known to react to O 3 , but knowledge of the sensitivity and type of responses of different species and plant communities is widely lacking. This review focuses on the ecological effects of O 3 on northern wild field layer plant species. Most of the 65 species examined thus far have proven to be quite tolerant of O 3 . Visible symptoms were observed in 54% of the 61 species studied, and growth reduction in 31% of the 55 species studied for growth. There were no signs to suggest that certain families or vegetation types are more sensitive or tolerant than others. There were, however, clear differences in sensitivity between the different species. It seems that forbs are usually more sensitive than grasses. It should be kept in mind, however, that we still lack knowledge on the responses of many common and abundant key species. The long-term effects are also far from clear. Hardly any field examinations have been carried out on the effects of O 3 on plant communities.

Detecting ozone and demonstrating its phytotoxicity in forested areas of Poland: A pilot study

Environmental Pollution, 1993

were measured and 03 phytotoxicity to tobacco (Nicotiana tabacum L.) was demonstrated in several forest locations in Poland during a pilot study from July-October, 1991. At southern and central locations in Poland, the 24-hour average 03 concentrations measured with a UV absorption photometer were in the range of 32-55 ppb, and the corresponding 1-hour maxima in the range of 39-83 ppb. At these locations longer period (four to fifteen days) average concentrations were determined using 03 passive sampiers (DGA, Inc.) and were reaching 60 ppb, while at Bialowieza in eastern Poland 03 concentrations averaged less than 40 ppb. In Szarow, near the Niepolomice Forest in southern Poland, 1-hour 03 maxima estimated from the data obtained using passive samplers were about 105 ppb in early September. At several locations in southern and central Poland, extensive 03 injury was determined on 03-sensitive Bel W-3 tobacco plants; such injury did not occur in the Bialowieza Forest of eastern Poland The results of this pilot study indicate that 03 is present at phytotoxic levels in southern and central Poland

Validation of leaf ozone symptoms in natural vegetation using microscopical methods

''Capsule'': Integration of markers of oxidative stress, from the subcellular to the leaf and needle level, proved to be a useful tool for the differential diagnosis and validation of ozone injury. Abstract Ozone injury to natural vegetation is being increasingly surveyed throughout the northern hemisphere. There exists a growing list of species showing visible 'ozone-like' symptoms which needs to be validated. This study presents the results from a test survey of ozone injury to forest vegetation in the light exposed sites of five Swiss level II plots, for the new ICP-Forests protocol. With AOT40 from 14 to 28 ppm. h in 2000, ten out of 49 woody plant species displayed typical symptoms, and four showed untypical symptoms. Symptom origin was investigated in nine and validated in seven species, using morphological, histological and cellular markers of oxidative stress and ozone-induced plant response. Independent of taxonomic position, ozone effects were characterized by the induction of oxidative stress in the mesophyll resulting in discrete and light-dependent hypersensitive-like responses and in accelerated cell senescence. The presented combination of cellular and morphological markers allows differential diagnosis of visible ozone injury.

Visible foliar injury as a tool for the assessment of surface ozone impact on native vegetation: a case study from the Jizersk hory Mts

Journal of Forest Science, 2010

Surface ozone is considered to be a very phytotoxic gaseous air pollutant. Its negative impacts at both the cell and the organ level have been shown, mainly as a result of experiments. However, the demonstration of ozone negative impacts on native plants is not explicit. An assessment of ozone impact on vegetation and ecosystems using indicators based on ambient ozone concentrations is insufficient and assessment techniques based on internal ozone dose and on real plant damage are more appropriate. Such a possible technique is the mapping of ozone visible symptoms due to ozone influence. The ICP-Forest method concerning ozone visible symptoms and the assessment of ozone influence were applied for the purposes of this case study. The visible symptoms are characterized by a few typical signs. Nevertheless, the identification of visible symptoms in native conditions can be problematic and misleading conclusions could be drawn. Therefore it is necessary to complete the identification of...

Ozone Umbrella: Effects of ground-level ozone on (upland) vegetation in the UK. Final report

The aim of this work package was to develop an increased understanding of the impacts of ozone on species of a range of different upland communities. The majority of the work was focussed on controlled laboratory experiments, supported by field observations, related to one important area of high conservation value-the Yorkshire Dales National Park. In this region, as in most such areas in the UK, a range of different plant communities are found, reflecting variation in soils, microclimate and management history. Some modifications of the original work programme have been made, reflecting partly difficulties with planned work, and partly the interest in investigating particular aspects of the findings which were judged to be of high value.

Plant Species Sensitivity Distributions for ozone exposure

Environmental Pollution, 2013

This study derived Species Sensitivity Distributions (SSD), representing a cumulative stressor-response distribution based on single-species sensitivity data, for ozone exposure on natural vegetation. SSDs were constructed for three species groups, i.e. trees, annual grassland and perennial grassland species, using species-specific exposureeresponse data. The SSDs were applied in two ways. First, critical levels were calculated for each species group and compared to current critical levels for ozone exposure. Second, spatially explicit estimates of the potentially affected fraction of plant species in Northwestern Europe were calculated, based on ambient ozone concentrations. We found that the SSD-based critical levels were lower than for the current critical levels for ozone exposure, with conventional critical levels for ozone relating to 8e20% affected plant species. Our study shows that the SSD concept can be successfully applied to both derive critical ozone levels and estimate the potentially affected species fraction of plant communities along specific ozone gradients.