Ozone and Temperature May Hinder Adaptive Capacity of Mediterranean Perennial Grasses to Future Global Change Scenarios.

Climate warming is recognized as a factor that threatens plant species in Mediterranean mountains. Tropospheric ozone (O) should also be considered as another relevant stress factor for these ecosystems since current levels chronically exceed thresholds for plant protection in these areas. The main aim of the present study was to study the sensitivity of four Mediterranean perennial grasses to O and temperature based on plant growth, gas exchange parameters (photosynthesis-A, stomatal conductance-g, and water use efficiency-WUE), and foliar macro- (N, K, Ca, Mg, P, and S) and micronutrients (B, Cu, Fe, Mn, Mo, and Zn) content.

Increased tropospheric ozone levels enhance pathogen infection levels of amphibians.

As a result of anthropogenic activities, changes to the chemistry of Earth's atmosphere pose a threat to ecosystem health and biodiversity. One such change is the increase in tropospheric ozone (O), which is particularly severe in the Mediterranean basin area, where the levels of this pollutant are chronically high during spring and summer time. Within this region, Mediterranean mountain ecosystems are hot spots for biodiversity which may be especially vulnerable to changes in O levels.

Ecological impacts of atmospheric pollution and interactions with climate change in terrestrial ecosystems of the Mediterranean Basin: Current research and future directions.

Mediterranean Basin ecosystems, their unique biodiversity, and the key services they provide are currently at risk due to air pollution and climate change, yet only a limited number of isolated and geographically-restricted studies have addressed this topic, often with contrasting results. Particularities of air pollution in this region include high O levels due to high air temperatures and solar radiation, the stability of air masses, and dominance of dry over wet nitrogen deposition. Moreover, the unique abiotic and biotic factors (e.

Validation of ozone response functions for annual Mediterranean pasture species using close-to-field-conditions experiments.

Ozone (O) critical levels have been established under the Long-Range Transboundary Air Pollution Convention to assess the risk of O effects in European vegetation. A recent review study has led to the development of O critical levels for annual Mediterranean pasture species using plants growing in well-watered pots at a coastal site and under low levels of competition. However, uncertainties remain in the extrapolation of the O sensitivity of these species under natural conditions.

Modelling the influence of peri-urban trees in the air quality of Madrid region (Spain).

Tropospheric ozone (O(3)) is considered one of the most important air pollutants affecting human health. The role of peri-urban vegetation in modifying O(3) concentrations has been analyzed in the Madrid region (Spain) using the V200603par-rc1 version of the CHIMERE air quality model. The 3.

Sensitivity analysis of a parameterization of the stomatal component of the DO3SE model for Quercus ilex to estimate ozone fluxes.

A sensitivity analysis of a proposed parameterization of the stomatal conductance (g(s)) module of the European ozone deposition model (DO(3)SE) for Quercus ilex was performed. The performance of the model was tested against measured g(s) in the field at three sites in Spain. The best fit of the model was found for those sites, or during those periods, facing no or mild stress conditions, but a worse performance was found under severe drought or temperature stress, mostly occurring at continental sites.

Parameterization of the stomatal component of the DO3SE model for Mediterranean evergreen broadleaf species.

An ozone (O3) deposition model (DO3SE) is currently used in Europe to define the areas where O3 concentrations lead to absorbed O3 doses that exceed the flux-based critical levels above which phytotoxic effects would be likely recorded. This mapping exercise relies mostly on the accurate estimation of O3 flux through plant stomata. However, the present parameterization of the modulation of stomatal conductance (g(s)) behavior by different environmental variables needs further adjustment if O3 phytotoxicity is to be assessed accurately at regional or continental scales.

Simulation of stomatal conductance for Aleppo pine to estimate its ozone uptake.

The data from a previous experiment carried out in open-top chambers to assess the effects of ozone (O3) exposure on growth and physiology of Aleppo pine (Pinus halepensis Mill.) were re-assessed to test the performance of the EMEP O3 stomatal conductance model used to estimate tree O3 uptake at a European scale. Aleppo pine seedlings were exposed during three consecutive years to three different O3 treatments: charcoal filtered air, non-filtered air and non-filtered air supplemented with 40 nl l(-1).

Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species.

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv.