Air pollution damage to cell membranes in lichens -Results of simple biological test applied in Rijeka,Yugoslavia Yugoslavia

A simple biological test developed by Pearson (1985) was applied to specimens of lichens collected within Rijeka city area to determine their plasma membrane integrity. Two strains of lichens were tested: Parmelia tiliacea (Hoffm.) Ach., a strain relatively tolerant, and Pannaria testacea Jørg., a strain more sensitive to air pollution. For comparison, the same test was applied to specimens of lichens collected at a coastal site in the vicinity of Rijeka as well as specimens from southern Norway. The obtained results on membrane damage are in good agreement with SO₂ concentration data (where available) and determined lichens zones within city area.     

Determining baseline element composition of lichens

Element-concentration baselines are given for Parmelia sulcata and associated soils. Parmelia chlorochroa was found sporadically and therefore only representative concentration ranges are reported for this species. Element data include (1) for lichens; Al, As, Ba, B, Ca, Cr, Cu, Fe, Hg, Mn, Ni, P, Sr, S, Ti, V, Y, and Zn; and (2) for soils: Al, Ba, Be, Ca, Cs, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Nb, P, Pb, Sr, S, Ti, V, Y, and Zn. Very little (usually < 10 %) of the variability in the element data for lichen material occurs regionally (> 7.2 km); thus, P sukata is, in general, chemically similar throughout the park. This same uniformity was found for soil geochemistry. Numerous samples collected at close intervals would be required, therefore, to produce detailed element-concentration maps for P. sulcata and soils. No instances of elemental phytotoxic conditions were found; however, P. sulcata apparently possesses large concentrations of Ba, Cu, Fe, Pb, S, V, and possibly Zn.     

Selenium Levels in Mainland Portugal

Selenium contents in the Portuguese (mainland) territory, resulting from a few environmental studies held since 1990 using lichens, vascular plants, soils and air particulate matter (APM), are presented and discussed herein. Values for Se in soils, epiphytic lichens and higher plants are within the typical ranges found in the literature. Compared to vascular plants, lichens display higher contents at the same locations. In what concerns Se in airborne particulates, all surveyed sites show values that are typical of urban areas. In two of such sites – Monchique and Carregado – Se concentrations in transplanted lichen thalli of the Parmelia genus (mostly, Parmelia sulcata Taylor) were compared to the results obtained from airborne matter, and a good correlation was found for the corresponding data-sets at either location. Other than the degree of association, it is especially noteworthy that the lichen transplants appear to accumulate much more Se at Monchique (a remote, rather clean site) than at Carregado (in the immediate vicinity of an oil-fired, power plant), even if its amount in the atmosphere is lower at the former location.     

Assessment of mercury dispersal in an abandoned mining area by soil and lichen analysis

The total Hg content in soil and in the epiphytic lichen Parmelia sulcata was determined in a former cinnabar mining area on Mt. Amiata. Metal concentrations in soil and in lichen are significantly related and decrease at increasing distances from the zone most affected by minespoil and by air which is still vented from mine shafts. On the basis of these results and of Al analysis, it seems likely that anomalous Hg content in Mt. Amiata lichens is mainly due to the out-gassing of volatile Hg from soil, from vegetation and, in the most heavily polluted zone, to the air from mine shafts.     

A study of airborne metals in Calcasieu Parish,Louisiana using the lichens,Parmelia praesorediosa and Ramalina stenospora

Two common species of lichens from southwestern Louisiana, Parmelia praesorediosa and Ramalina stenospora, were analyzed thrice over a period of 9 mo. Samples were analyzed for Th, Cs, Se, Hg, Cr, Ir, Ce, Sc, Rb, Fe, Zn, Co, Ta, Eu, K, and Sb. No statistical differences in concentration over the time interval studied were seen. However, discriminant analysis showed a significant (>90%) difference between elemental content and species. The data could be separated into two geographical areas that were statistically different. Highest concentrations were observed within a 10.8-km radius of the industrial/urban zone.     

The influence of three sour gas processing plants on the ecological distribution of epiphytic lichens in the vicinity of fox creek and Whitecourt,Alberta, Canada

The ecological distributions of epiphytic lichens have been reduced by SO₂ emissions from three sour gas processing plants located near Fox Creek and Whitecourt, Alberta. Pollutants tend to concentrate in drainage channels leading to the Athabasca River. These channels parallel the prevailing wind. No sites were encountered which totally lacked lichens but at sites within 1 to 2 km downwind of gas plants and associated S storage blocks, the epiphytic lichen flora was reduced in variety, cover and vitality. An Index of Atmospheric Purity (IAP) was calculated from epiphyte data using selected indicator species and air pollution zones determined. Zone maps of relative air purity were generated using the SYMAP mapping package. Improvements to previous IAP methodologies are suggested. Average sulfation rates, S content, and stable S isotope abundance ratios are discussed as they relate to lichen diversity, vitality and IAP values.     

Microbial biomass and activity in soil and litter underPinus sylvestris, Picea abies andBetula pendula at originally similar field afforestation sites

Microbial biomass C and N, and activities related to C and N cycles, were compared in needle and leaf litter, and in the uppermost 10 cm of soil under the litter layer in Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.) and silver birch (Betula pendula L.) stands, planted on originally similar field afforestation sites 23–24 years ago. The ground vegetation was differentiated under different tree species, consisting of grasses and herbs under birch and pine, and mosses or no vegetation with a thick layer of needles under spruce. The C:N ratio of the soils was 13–21 and the soil pH_{CaCl 2} 3.8–5.2. Both showed little variation under different tree species. Microbial biomass C and N, C mineralization, net ammonification, reduction) did not differ significantly in soil under different tree species either. Birch leaf litter had a higher pH_{CaCl 2} (5.9) than spruce and pine needle litter (pH 5.0 and 4.8, respectively). The C:N ratio of spruce needles was 30, and was considerably higher in pine needles (69) and birch leaves (54). Birch leaves tended to have the highest microbial biomass C and C mineralization. Spruce needles appeared to have the highest microbial biomass N and net formation of mineral N, whereas formation of mineral N in pine needles and birch leaves was negligible. Microbial biomass C and N were of the same order of magnitude in the soil and litter samples but C mineralization was tenfold higher in the litter samples.     

Effect of industrial emissions on membrane permeability of epiphytic lichens in Northern Finland and the Kola Peninsula industrial areas

The impact of air pollution on membrane permeability of the epiphytic lichens Hypogymnia physodes and Bryoria fuscescens was studied in northern Finland and the Kola Peninsula to assess the effects of the Kola industrial emissions. The conductivity and quantity of K⁺ in leachates of the lichens were determined both as absolute and relative leakage. The K⁺ leakage from the lichens was the most sensitive indicator of membrane disturbance. Positive relationships between K⁺ leakage and decreasing distance from pollution sources and modelled atmospheric SO₂ concentrations were found and the K⁺ leakage and Cu and Ni concentrations of Scots pine bark were also highly correlated. The relative conductivity of leachates was inversely related to distance from sources, while the absolute conductivity of leachates from lichens was positively correlated with bark S. The ion leakage was higher in fruticose Bryoria fuscescens than in foliose Hypogymnia physodes, but the overall response to pollution was similar in both species. The methods used were able to identify areas of disturbed membrane function around the Kola industrial areas and local point sources in northern Finland. However, the majority of the studied sites in Finnish Lapland can be regarded as undisturbed background areas with respect to these sensitive lichens.     

The Enchytraeidae of spruce forest plots of different exposure and acid deposition in a German mountain range

Enchytraeidae were studied at spruce forest sites (Harz, Germany) differing in their exposure and soil acidity affected by acid deposition. Total density ranged between 38 000 and 59 000 ind. m^–2 and biomass between 0.5 and 1 g m^–2 d.m. (annual means). Of the seven species recorded, Cognettia sphagnetorum, Marionina clavata, and Achaeta camerani were dominant. The site affected most by acidification had the highest densities and lowest species number. Population dynamics and vertical distributions were affected by climate. Field and laboratory data provide evidence for sexual reproduction in C. sphagnetorum. Substrate preference experiments showed this species to prefer spruce litter from the O_L-Horizon to that from the O_H-Horizon, and spruce litter to beech litter.     

Conservation of epiphytic lichens: Significance of remnant aspen (Populus tremula) trees in clear-cuts

In the boreal forest landscape, aspen has been effectively selected against in favour of conifers. The decrease in aspen is of particular concern since it has more host-specific species associated with it than any other boreal tree species. Recently forest management systems have begun to include green-tree retention in order to maintain structural diversity. We initiated this study in order to investigate whether retained aspen trees provide suitable habitats for epiphytic lichens and, if so, whether this varies according to species characteristics, such as morphology and photobiont. We chose to investigate the abundance and vitality of five species: three foliose cyanobacterial lichens (Collema curtisporum, Collema furfuraceum and Leptogium saturninum) and two crustose green-algal lichens (Biatora epixanthoides and Mycobilimbia carneoalbida). These lichens were examined on aspen within forest stands and on remnant aspen in clear-cuts at eight localities, in northern Sweden. Our results show that the response to exposure following clear-felling differs between species according to their morphology. The two crustose lichens were more abundant in the forest stands compared to the clear-cuts. In the clear-cuts, they mainly occurred on the northern sides of the trunks. Even 24 years after cutting, the three cyanolichens were equally or even more abundant on trees in the clear-cuts than in the forest stands. However, they were mainly found on the northern sides of the remnant aspen. We suggest that remnant aspen trees may function as suitable substrate and as stepping stones for colonisation of new stands, at least for the cyanolichens studied here.     

Artificial dispersal of endangered epiphytic lichens: a tool for conservation in boreal forest landscapes

Due to increasing fragmentation of the boreal forests of Fennoscandia, a number of epiphytic lichens are now becoming threatened. Since these species typically are limited by a poor ability of dispersal, one possible but largely unexplored strategy for conservation is to disperse lichen material artificially into suitable habitats. Therefore, the objective of this study was to evaluate survival and vitality in lichen fragments from Evernia divaricata (L.) Ach. and Ramalina dilacerata (Hoffm.) Hoffm. after transplantation into three different stand types situated in northern Sweden, using different fragment sizes and modes of transplantation. After one year, survival ranged between 85% and 97.5%, and new growth occurred at all transplantation sites. The study has shown that transplantations of small fragments might constitute a resource-efficient option for establishment of new populations of endangered lichen species, or for enlarging their populations at the present sites of occurrence. In addition, the mode of transplantation was of importance for fragment vitality.     

Do earthworms compete for food?

Three species of non-native earthworms, Microscolex dubius (Fletcher), Eisenia foetida (Sav.) and Allolobophora trapezoides Dugès are common and widespread in suburban gardens of Perth, Western Australia. Eisenia tends to dominate numerically mixtures of these species. Laboratory experiments were set up to detect intra- or interspecific competitive interactions. Changes of biomass of worms in mixed species populations indicate that Microscolex under the experimental conditions adopted is at a competitive disadvantage when with Eisenia. The biomass of Eisenia was adversely affected by conspecifics but not by Microscolex. Ratio diagrams of biomasses were used to illustrate the temporal dynamics of these processes. During the first 2 weeks of the experiment neither species had an advantage over the other, but between weeks 2 and 5 mixtures tended toward an equilibrium with Eisenia contributing 62–67% of the total biomass. After week 5 the advantage enjoyed by Eisenia became independent of its biomass. A similar experiment conducted with Eisenia and Allolobophora yielded a stable coexistence within 11 weeks. The object of competition is most likely food. Two possible mechanisms, involving differences in excretory or digestive physiology, that could account for the decline of Microscolex are outlined.     

The relative tolerance of some Eucalyptus species to ozone exposure

Surface ozone (O₃) concentrations have proved to be difficult to control and regional (0₃) concentrations appear to be increasing in many parts of the world. Eucalyptus species are widely used as plantation trees in many regions that have Mediterranean, warm temperate and subtropical climates. An increased knowledge of the effects of tropospheric O₃ on Eucalyptus trees may assist in the management of these plantations. The present study was set up to evaluate injury and measure growth reduction caused by O₃ in eight Eucalyptus species. Seven month old saplings were exposed to diumally varied concentrations of 26 or 172 nil^?1 (0₃) (7h mean) 7h day^?1, 5 days in every 14 days, for 18 weeks. The plants were grown in open top field chambers fitted with rain excluders. Significant differences were found between the responses of different species. There was no visible injury or dry weight reduction in E. globulus. However O₃ exposure caused a 30% weight reduction and 90% leaf injury in E. microcorys. E. gomphocephala also experienced a 30% weight reduction but no significant leaf injury. Hence Eucalyptus plantations in regions with the potential for photochemical smog formation, such as some of the rapidly developing industrialising nations in Asia and South America, will need to consider O₃ tolerance when selecting plantation trees.     

Treatment of Domestic Wastewater by Three Plant Species in Constructed Wetlands

Three common Appalachian plant species (Juncus effusus L., Scirpus validus L., and Typha latifolia L.) were planted into small-scale constructed wetlands receivingprimary treated wastewater. The experimental design includedtwo wetland gravel depths (45 and 60 cm) and five plantingtreatments (each species in monoculture, an equal mixture of the three species, and controls without vegetation), with two replicates per depth × planting combination. Inflow rates (19 L day^-1) and frequency (3 times day^-1) were designed to simulate full-scale constructed wetlands as currently used for domestic wastewater treatmentin West Virginia. Influent wastewater and the effluent from each wetland were sampled monthly for ten physical, chemical and biological parameters, and plant demographic measurements were made. After passing through these trough wetlands, the average of all treatments showed a 70% reduction in total suspended solids (TSS) and biochemical oxygen demand (BOD), 50 to 60% reduction in nitrogen (TKN), ammonia and phosphate, anda reduction of fecal coliforms by three orders of magnitude. Depth of gravel (45 or 60 cm) had little effect on wetland treatment ability, but did influence Typha and Scirpus growth patterns. Gravel alone provided significant wastewater treatment, but vegetation further improved many treatment efficiencies. Typha significantly out-performedJuncus and Scirpus both in growth and in effluent quality improvement. There was also some evidence that the species mixture out-performed species monocultures.Typhawas the superior competitor in mixtures, but a decline in Typha growth with distance from the influent pipe suggested that nutrients became limiting or toxicities may have developed.     

Foliar sensitivity of pinto bean and soybean to ozone as affected by temperature,potassium nutrition and ozone dose

Pinto bean (Phaseolus vulgaris L.) and soybean [Glycine max (L.) Merv.] were exposed to O₃ to determine the interactions of growth temperature, exposure temperature, K nutrition and doses of O₃ on their foliar sensitivity. Pinto bean developed more foliar injury than soybean. Pinto bean were most sensitive when grown and exposed at 28°C. Growth and exposure temperature interacted in the development of foliar injury on pinto bean, but only growth temperature influenced the amount of foliar injury on soybean. Both species developed more foliar injury when grown with low K nutrition. There was no relationship between foliar injury and reducing sugars or sucrose content of the leaves.     

Performance of phosphate-solubilizing bacteria in soil under high phosphorus conditions

A way to bring phosphate-saturated soils back to an environmentally safe P level is by P mining through plants. Phosphate-solubilizing bacteria (PSB) could be very useful for increasing mining efficiency over time. The goal of this research was to investigate the adaptation and performance of PSB in conditions of high total P content in soil. In the first experiment, the P-solubilizing capacity of five PSB species (three Bacillus spp. and two Pseudomonas spp.) were tested under fully controlled conditions on several growth media with different forms of insoluble phosphate (FePO₄, AlPO₄, or (Ca)₃(PO₄)₂) added at different rates. The colony growth after 14 days of inoculation demonstrated that all five bacteria were able to proliferate and solubilize P on each of the tested growth media, in contradiction with the normally used technique of halo determination. In the second experiment, the same bacterial species were inoculated in pure quartz sand amended with a nutrient solution and P was added separately in an insoluble form, as Fe–P, Al–P, or Ca–P. The extractable ammonium lactate ranged from 3.2 to 6.9 and 29.0 to 40.7 mg?kg^?1 sand for the insoluble Al–P and Fe–P treatments, respectively. Pseudomonas putida and Bacillus brevis performed best as PSB at high P concentration where the P is fixed with Al or Fe. In the third experiment, P. putida and B. brevis were inoculated in an acidic sandy, P-saturated soil for 4 weeks. The inoculation of the PSB gave promising results in solubilizing P.     

Chicory (Cichorium intybus L.) and dandelion (Taraxacum officinale Web.) as phytoindicators of cadmium contamination

Chicory (Cichorium intybus L.) and dandelion (Taraxacum officinale Web.) were demonstrated to be potential indicator plants for heavy metal contaminated sites. Chicory, grown with 0.5–50 μM cadmium (Cd) in nutrient solution, accumulated 10–300 μM Cd g^?1 in shoots and 10–890 μg Cd μg^?1 in roots and rhizomes. With dandelion, 20–410 μg Cd μg^?1 was found in shoots and 20–1360 μg Cd μg^?1 in roots and rhizomes. An inverse correlation existed between chlorophyll and Cd concentrations in shoots of both species. Accumulation of Cd from nutrient solution was similar with the counter-anions SO₄ ^2?, Cl^1? and NO₃ ^? in chicory. In chicory grown in Cd-amended (11.2 kg Cd ha^?1 applied five years previously) soils, Cd concentrations were substantially higher than in controls in all plant parts following the order: leaf > caudex > stem > root and rhizome. The above trend was the opposite of that observed in solution culture, where Cd accumulation was higher in roots and rhizomes than in shoots. Higher cadmium accumulation was found from a Cd-treated sand (Grossarenic Paleudult) than from a loamy sand (Typic Kandiudult) soil type. Chicory and dandelion are proposed indicator plants of cadmium contamination, and both have the potential to be an international standard heavy phytomonitor species of heavy metal contaminantion.     

Effect of crude oil on gas exchange functions of Juncus roemerianus and Spartina alterniflora

The effect of crude oil on gas exchange functions of Juncus roemerianus and Spartina alterniflora, two important U.S. Gulf Coast plant species, were examined. Plants were exposed to petroleum hydrocarbons (Mexican Sour type) mixed with water at 4.4 mL L^?1 (2 L m^?2). Coating entire leaf with oil resulted in cessation of photosynthetic activity. Partial leaf exposure to oil resulted in net photosynthesis decrease in both species shortly after exposure. Net photosynthesis remained within 71 and 94% of control plants in J. roemerianus during the first four weeks of the experiment. In S. alterniflora, photosynthetic rates averaged between 53 to 80% of control plants during the same period. Four weeks following the partial oiling, net photosynthesis began to improve in both species. Partial oil coverage of leaves of both species resulted in reduction in normal photosynthetic activity with no lethal effects. By the end of the laboratory study, there was no significant reduction in production of new shoots or the overall growth of either species.     

Temporal changes in metal levels of the lichens Parmotrema praesorediosum and Ramalina stenospora,Southwest Louisiana

Two species of lichen native to southwest Lousiana, Parmotrema praesorediosum (Nyl.) Hale and Ramalina stenospora, Mull. Arg. have been investigated as air pollution monitors. Over the period 1983–88 samples were collected at 18 stations in the Lake Charles/Westlake/Sulphur area. The samples were analyzed for A1, Fe, Cu, Pb, Cd, Hg, Cr, and Zn. When metal concentrations in lichens were plotted vs year for certain representative stations, a dramatic reduction in the concentrations of certain metals was seen after 1983. When the most recent data are compared with those previously obtained, the effects of the industrial zone, which was previously demonstrated, have now all but disappeared.     

Casuarina and Eucalyptus response to single and multiple gaseous air pollutants

Casuarina cunninghamiana and Eucalyptus camadulensis (Egyptian var.) plants were exposed to 0.20 and 0.40 μL L^?1 O₃, SO₂ or NO₂ for 6 hr daily for 10 days. Eucalyptus plants were very sensitive to SO₂ and NO₂ and less sensitive to O₃. Casuarina plants were insensitive to the 3 gases. The rate of sorption of the 3 gases was estimated over a 10 day exposure to 0.20 μL L^?1 pollutant concentration singly and in a 3-gas mixture. Casuarina plants removed air pollutants more efficiently than Eucalyptus plants. Leaves of both species generally sorbed about the same volume of a given gas from the mixture and from the same single gas. The sorption rate over the 10 day exposure was almost constant after a higher sorption rate during the first day for both species.