Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis, it was found that the ultrastructure of chloroplasts were changed, the shape of the chloroplasts altered and the numbers of grana that were asymmetrical increased; the numbers of grana and thylakoids decreased under the stress of Cd and Zn. The results indicated that the complex pollution involving Cd and Zn resulted in the membrane system of chloroplasts being damaged. When external phosphorus was applied, the numbers of damaged chloroplasts were significantly reduced and the nucleoli were better formed than those that did not receive phosphorus treatment. Moreover, many phosphate deposits were found in the vacuoles and on the surface of the roots, which were formed by phosphorus complexing with Cd (Ksp = 2.53 x 10-33) and Zn (Ksp = 9.00 x 10-33), respectively. Treatment with phosphorus conduced an increased chlorophyll content in plants compared with those that did not receive external phosphorus. External P could decrease the bioavailability of Cd and Zn.

Visible ozone symptoms on leaves are expressions of physiological mechanisms to cope with oxidative stresses. Often, the symptoms consist of stippling, which corresponds to localized cell death (hypersensitive response, HR), separated from healthy cells by a layer of callose. The HR strategy tends to protect the healthy cells and in most cases the efficiency of chlorophyll to trap energy is not affected. In other cases, the efficiency of leaves to produce biomass declines and the plant loses its photosynthetic apparatus replacing it with a new, more efficient one. Another strategy consists of the production of pigments (anthocyanins), and leaves become reddish. In these cases, the most significant physiological manifestation consists of the enhanced dissipation of energy. These different behavior patterns are reflected in the initial events of photosynthetic activity, and can be monitored with techniques based on the direct fluorescence of chlorophyll a in photosystem II, applying the JIP-test. Analytical techniques based on the direct fluorescence of chlorophyll a, allow us to discriminate species-specific physiological behavior in relation to ozone air pollution.

Options for wetland creation or restoration might be limited because of the presence of contaminants in the soil. The influence of hydrological management on the pore water concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn in the upper soil layer of a contaminated overbank sedimentation zone was investigated in a greenhouse experiment. Flooding conditions led to increased Fe, Mn, Ni and Cr concentrations and decreased Cd, Cu and Zn concentrations in the pore water of the upper soil layer. Keeping the soil at field capacity resulted in a low pore water concentration of Fe, Mn and Ni while the Cd, Cu, Cr and Zn concentrations increased. Alternating hydrological conditions caused metal concentrations in the pore water to fluctuate. Formation and re-oxidation of small amounts of sulphides appeared dominant in determining the mobility of Cd, Cu, and to a lesser extent Zn, while Ni behaviour was consistent with Fe/Mn oxidation and reduction. These effects were strongly dependent on the duration of the flooded periods. The shorter the flooded periods, the better the metal concentrations could be linked to the mobility of Ca in the pore water, which is attributed to a fluctuating CO2 pressure. The hydrological regime is a key factor in determining the metal concentration in the pore water of a contaminated sediment-derived soil.

The urban landscape is comprised of many land uses, none more intensively managed than turfgrass; however, quantification of nutrient losses from specific land uses within urban watersheds, specifically golf courses is limited. Nitrate (NO3-N) and dissolved reactive phosphorus (DRP) were measured on a golf course in Austin, TX, USA from April 1, 1998 to March 31, 2003. NO3-N and DRP concentrations measured in storm flow were significantly greater exiting the course compared to those entering the course. Significant differences were also measured in baseflow NO3-N concentrations. The measured loading from the course was 4.0 kg NO3-N ha 1 yr 1 (11% of applied) and 0.66 kg DRP ha 1 yr 1 (8% of applied). The resulting concentrations contributed by the course were 1.2 mg L 1 NO3-N and 0.2 mg L 1 DRP. At these levels, NO3-N poses minimal environmental risk. However, the DRP concentration is twice the recommended level to guard against eutrophication

Human activity is changing air quality and climate in the US Pacific Northwest. In a first application of non-metric multidimensional scaling to a large-scale, framework dataset, we modeled lichen community response to air quality and climate gradients at 1416 forested 0.4 ha plots. Model development balanced polluted plots across elevation, forest type and precipitation ranges to isolate pollution response. Air and climate scores were fitted for remaining plots, classed by lichen bioeffects, and mapped. Projected 2040 temperatures would create climate zones with no current analogue. Worst air scores occurred in urban-industrial and agricultural valleys and represented 24% of the landscape. They were correlated with: absence of sensitive lichens, enhancement of nitrophilous lichens, mean wet deposition of ammonium >0.06 mg l-1, lichen nitrogen and sulfur concentrations >0.6% and 0.07%, and SO2 levels harmful to sensitive lichens. The model can detect changes in air quality and climate by scoring re-measurements. Lichen-based air quality and climate gradients in western Oregon and Washington are responsive to regionally increasing nitrogen availability and to temperature changes predicted by climate models.

In industrial barrens adjacent to a nickel-copper smelter at Monchegorsk, the Kola Peninsula, root colonisation in Deschampsia flexuosa by arbuscular mycorrhizal (AM)-type of hyphae was lower than in unpolluted forests (60.9 vs. 80.4%), while Olpidium-colonisation showed a marginally significant decline, and dark septate endophytic (DSE) hyphal colonisation was not affected. We detected an interactive effect of pollution and a neighbouring tree on DSE hyphal colonisation: at the highly polluted sites, colonisation was lower in D. flexuosa growing near trees, whereas at sites with low pollution the presence of the neighbouring tree had no effect on colonisation. High numbers of intracellular DSE sclerotia in the industrial barrens (13.3 vs. 3.4%) may indicate a survial strategy in an unfavourable environment and a dispersal strategy into a more favourable environment. While lower root colonisation by AM fungi has been also earlier reported in graminoids for heavy metal contamination, the results on other ubiquitous fungi colonising D. flexuosa roots are more novel. Severe pollution decreased root colonisation by some fungal groups; neighbouring trees decreased root colonisation by dark septate endophytic fungi in highly polluted sites.

The United States and Canada currently use exposure-based metrics to protect vegetation from O3. Using 5 years (1999-2003) of co-measured O3, meteorology and growth response, we have developed exposure-based regression models that predict Populus tremuloides growth change within the North American ambient air quality context. The models comprised growing season fourth-highest daily maximum 8-h average O3 concentration, growing degree days, and wind speed. They had high statistical significance, high goodness of fit, include 95% confidence intervals for tree growth change, and are simple to use. Averaged across a wide range of clonal sensitivity, historical 2001-2003 growth change over most of the 26 M ha P. tremuloides distribution was estimated to have ranged from no impact (0%) to strong negative impacts (-31%). With four aspen clones responding negatively (one responded positively) to O3, the growing season fourth-highest daily maximum 8-h average O3 concentration performed much better than growing season SUM06, AOT40 or maximum 1 h average O3 concentration metrics as a single indicator of aspen stem cross-sectional area growth. A new exposure-based metric approach to predict O3 risk to North American aspen forests has been developed.

The Bitterfeld/Wolfen region is a megasite with multiple contaminant sources from more than a century of industrial activity, which have a considerable impact on the environment. At present, the contaminated groundwater covers an area of about 25 km2 and poses a threat for the surrounding aquifers and the Mulde River. This study focuses on the Schachtgraben, a man-made channel in the Mulde Floodplain that collects the effluents of the industrial area. It aims to characterise the relationship between surface water (channels, rivers) and the groundwater in the shallow Quaternary aquifer. Waters are Ca-SO4 type with TDS reaching 3.8 g L-1 in the industrial area. Stable isotopes (δ18O, δ2H) show that two of the rivers are recharged mainly by groundwater that can be divided into two groups. Strontium isotopes (87Sr/86Sr) designate different geochemical end-members and enable the identification of mixing between natural and anthropogenic surface and groundwater. Modern geochemical and isotope techniques demonstrated groundwater to be the main source of surface water pollution in a hotspot of pollution in the Elbe Watershed.

For most trace elements, the technique of phytoextraction needs significant improvements to become practically feasible. Calculations for Cd revealed that the amount of Cd taken up by Thlaspi caerulescens or Salix spp. needs at least to be the double of the present amount to slightly decrease the Cd concentration in the upper 0.5 m of the soil within a period of 10 years. Additionally, metals taken up by the plants might pose an important risk. Alternatives as bioavailable contaminant stripping and phytostabilization might be more appropriate. Phytoextraction efficiency should be improved and associated risks need more attention before phytoextraction can be established as a commercial technology.

To determine the source of dissolved inorganic nitrogen (N) in runoff, approx. 35 kg N enriched with the stable isotope 15N (2110[per thousand] δ15N) was added to a mature coniferous forested catchment for one whole year. The total N input was approx. 50 kg ha-1 year-1. The enrichment study was part of a long-term whole-catchment ammonium nitrate addition experiment at Gårdsjön, Sweden. The 15N concentrations in precipitation, throughfall, runoff and upper forest floor were measured prior to, during, and 3-9 years following the 15N addition. During the year of the 15N addition the δ15N level in runoff largely reflected the level in incoming N, indicating that the leached NO3- came predominantly from precipitation. Only 1.1% of the incoming N was lost during the year of the tracer addition. The cumulative loss of tracer N over a 10-year period was only 3.9% as DIN and 1.1% as DON. 15N tracer addition showed that initially the main source of NO3- in runoff was N from atmospheric deposition.