Effect of the nitrification inhibitor dicyandiamide on microbial communities and N<Subscript>2</Subscript>O from an arable soil fertilized with ammonium sulphate

Nitrous oxide (N₂O) affects climate change as a greenhouse gas and indirectly contributes to stratospheric ozone depletion. The main source of N₂O in soils is denitrification which requires high soil moisture, carbon and nitrate. Nitrification inhibitors can be used to mitigate emissions of N₂O from soils. In Portugal, fertilisers are often applied when soils are still relatively warm and moist conditions conducive to denitrification. A Portuguese arable soil was inhibited with dicyandiamide, a nitrification inhibitor and the effect on soil microbiological activity and composition was determined after 46 days. Soils were then incubated and received carbon and ammonium under high soil water conditions and mineral N and N₂O fluxes were measured during 22 days. We found that dicyandiamide decreased microbial populations and activity, but did not alter composition. Pre-conditioning of the soil with dicyandiamide was 80% more effective in reducing fluxes of N₂O than simultaneous application with fertiliser.     

Ecotoxicological characterization of tannery wastewater in Dhaka, Bangladesh

Tanning industries are one of the main economic activities in Bangladesh. It has been well documented that wastewater discharged from tanneries without appropriate treatment results in detrimental effects on the ecosystem. No ecotoxicity evaluation of any aquatic environment in Bangladesh has been conducted so far. In this study a battery of toxicity bioassays and chemical analysis were carried out from water samples obtained from three sampling points: upstream from discharging site on River Buriganga (S1), raw wastewater effluent (S2), and downstream the discharging sluice gate (S3), in the Hazaribagh tannery area of Dhaka City, Bangladesh. While S1 and S3 water samples did not show significant toxicity in the bioassays tested, S2 exhibited high acute toxicity to the bacterium Vibrio fischeri (15-min Microtox test, EC50 = 9.8%), the higher plant Lactuca sativa (5-day root elongation inhibition test, EC50 = 14.2%), and the microcrustacean Daphnia magna (24-hour mobility test, EC50 = 31.5%). The results suggested that the raw wastewater effluent had detrimental effects on broad spectrum of organisms in the aquatic ecosystem and bacterium was the most sensitive. The chemical analysis revealed that sample S2 contained an extremely high concentration of chromium (47 g l(-1)). Additionally microbiological analysis indicated that the sampling area is impacted by fecal pollution, increasing the environmental health risk for its inhabitants.     

Assessment of urban air pollution and it's probable health impact

The present study deals with the quantitative effect of vehicular emission on ambient air quality during May 2006 in urban area of Lucknow city. In this study SPM, RSPM, SO2, NOx and 7 trace metals associated with RSPM were estimated at 10 representative locations in urban area and one village area for control. Beside this, air quality index (AQI), health effects of different metals and mortality were assessed. The 24 hr average concentration of SPM, RSPM, SO2 and NOx was found to be 382.3, 171.5, 24.3 and 33.8 microg m(-3) respectively in urban area and these concentrations were found to be significantly (p < 0.01) higher by 94.8, 134.8, 107.4 and 129.6% than control site respectively The 24 hr mean of SPM and RSPM at each location of urban area were found to be higher than prescribed limit of National Ambient Air Quality Standard (NAAQS) except SPM for industrial area. The 24 hr mean concentration of metals associated with RSPM was found to be higher than the control site by 52.3, 271.8, 408.9, 75.81, 62.7, 487.54 and 189.5% for Fe, Cu, Pb, Zn, Ni, Mn and Cr respectively. The inter correlation of metals Pb with Mn, Fe and Cr; Zn with Ni and Cr; Ni with Cr; Mn with Fe and Cu with Cr showed significant positive relation either at p < 0.05 or p < 0.01 level. Metals Pb, Mn and Cr (p < 0.01) and Cu (p < 0.05) showed significant positive correlation with RSPM. These results indicate that ambient air quality in the urban area is affected adversely due to emission and accumulation of SPM, RSPM, SO2, NOx and trace metals. These pollutants may pose detrimental effect on human health, as exposure of these are associated with cardiovascular and respiratory diseases, neurological impairments, increased risk of preterm birth and even mortality and morbidity.     

Toxizität und Risk Assessment fluvialer Sedimente und Schwebstoffe: Eine kurze Übersicht bisheriger und neuerer Entwicklungen

Background In recent years, sediments have become a central topic of scientific and public discussion as an important factor for determining water quality. While the quality of surface waters in Germany has significantly improved during the past years, highly contaminated sediments still create a considerable threat to the quality of several European catchment areas. Main features Here, we summarize different concepts and methods for the assessment of sediment quality and report on some novel integrative test methods for assessing sediment toxicity including contaminant re-mobilization during simulated re-suspension events. Results and discussion Currently, different approaches for assessment of sediment pollution exist. While instrumental chemical analyses are not suitable to accurately describe sediment toxicity, combinations of biological and chemical test procedures and integrated approaches, for example weight-of-evidence studies and effect-directed analysis (EDA), have the potential to identify key contaminants. Inter-disciplinary studies combining hydrodynamic and toxicological aspects coupled to real exposure of aquatic organisms to contaminants are currently being developed. Conclusions Monitoring and assessment of sediment quality are of increasing importance, not only for national legislation but also for the implementation of the European Water Framework Directive (WFD). Integrated approaches for the determination of sediment stability play a key role in the appropriate sediment-monitoring strategies.     

Experimental Test of Postfire Management in Pine Forests: Impact of Salvage Logging versus Partial Cutting and Nonintervention on Bird–Species Assemblages

Abstract: There is an intense debate about the effects of postfire salvage logging versus nonintervention policies on regeneration of forest communities, but scant information from experimental studies is available. We manipulated a burned forest area on a Mediterranean mountain to experimentally analyze the effect of salvage logging on bird–species abundance, diversity, and assemblage composition. We used a randomized block design with three plots of approximately 25 ha each, established along an elevational gradient in a recently burned area in Sierra Nevada Natural and National Park (southeastern Spain). Three replicates of three treatments differing in postfire burned wood management were established per plot: salvage logging, nonintervention, and an intermediate degree of intervention (felling and lopping most of the trees but leaving all the biomass). Starting 1 year after the fire, we used point sampling to monitor bird abundance in each treatment for 2 consecutive years during the breeding and winter seasons (720 censuses total). Postfire burned‐wood management altered species assemblages. Salvage logged areas had species typical of open‐ and early‐successional habitats. Bird species that inhabit forests were still present in the unsalvaged treatments even though trees were burned, but were almost absent in salvage‐logged areas. Indeed, the main dispersers of mid‐ and late‐successional shrubs and trees, such as thrushes (Turdus spp.) and the European Jay (Garrulus glandarius) were almost restricted to unsalvaged treatments. Salvage logging might thus hamper the natural regeneration of the forest through its impact on assemblages of bird species. Moreover, salvage logging reduced species abundance by 50% and richness by 40%, approximately. The highest diversity at the landscape level (gamma diversity) resulted from a combination of all treatments. Salvage logging may be positive for bird conservation if combined in a mosaic with other, less‐aggressive postfire management, but stand‐wide management with harvest operations has undesirable conservation effects.     

Ants as a Measure of Effectiveness of Habitat Conservation Planning in Southern California

Abstract: In the United States multispecies habitat conservation plans were meant to be the solution to conflicts between economic development and protection of biological diversity. Although now widely applied, questions exist concerning the scientific credibility of the conservation planning process and effectiveness of the plans. We used ants to assess performance of one of the first regional conservation plans developed in the United States, the Orange County Central‐Coastal Natural Community Conservation Plan (NCCP), in meeting its broader conservation objectives of biodiversity and ecosystem‐level protection. We collected pitfall data on ants for over 3 years on 172 sites established across a network of conservation lands in coastal southern California. Although recovered native ant diversity for the study area was high, site‐occupancy models indicated the invasive and ecologically disruptive Argentine ant (Linepithema humile) was present at 29% of sites, and sites located within 200 m of urban and agricultural areas were more likely to have been invaded. Within invaded sites, native ants were largely displaced, and their median species richness declined by more than 60% compared with uninvaded sites. At the time of planning, 24% of the 15,133‐ha reserve system established by Orange County NCCP fell within 200 m of an urban or agricultural edge. With complete build out of lands surrounding the reserve, the proportion of the reserve system vulnerable to invasion will grow to 44%. Our data indicate that simply protecting designated areas from development is not enough. If habitat conservation plans are to fulfill their conservation promise of ecosystem‐level protection, a more‐integrated and systematic approach to the process of habitat conservation planning is needed.     

Klima-Biomonitoring: Nachweis des Klimawandels und dessen Folgen für die belebte Umwelt

Hintergrund und ZielEs wird vorgeschlagen, Biomonitoring-Verfahren zu verwenden, um Auswirkungen des Klimawandels auf die belebte Umwelt zu erkennen, zu bewerten und zu dokumentieren, weil ? es mit dieser Methode gelingt, klimainduzierte Veränderungen in besonders empfindlichen Gebieten in Deutschland mit ihren Lebensräumen, Lebensgemeinschaften und Arten darzustellen, ? es bezüglich Zuwanderung und Ausbreitung neuer Schädlinge und Krankheitserreger für Mensch, Tier und Pflanze nach bzw. in Deutschland relevante Informationen liefern kann, ? damit der Politik zur Bewertung der Auswirkungen des Klimawandels wichtige Informationen, Handreichungen und Entscheidungsgrundlagen zur Verfügung gestellt werden können und ? auf dieser Grundlage geeignete Anpassungsmaßnahmen eingeleitet und auf ihre Wirksamkeit geprüft werden können, wie beispielsweise in der Deutschen Anpassungsstrategie (BMU 2009) beschrieben. Für Biomonitoring-Verfahren, die geeignet sind, Auswirkungen des Klimawandels anzuzeigen, wird der Begriff Klima-Biomonitoring vorgeschlagen Diese Verfahren sollten aus verschiedenen Gründen (u.?a. abgestimmte Methodik und gleiche Datenbasis, Kostenersparnis) unter Beteiligung aller Bundesländer umgesetzt werden. Bioindikation ist bereits heute ein unverzichtbares Verfahren, frühzeitig Veränderungen in der belebten Umwelt zu erkennen und somit Hinweise auf besondere Gefahren zu liefern (Frühwarnsystem). Für das Klima-Biomonitoring werden vorzugsweise bestehende Monitoringsysteme mit ihren bereits erhobenen Daten ausgewertet und mitgenutzt. Material und Methoden Das Klima-Biomonitoring greift auf bereits eingeführte und bewährte Methoden der Bioindikation von Umweltveränderungen zurück. Bestehende Methoden werden im Hinblick auf die besonderen, durch den Klimawandel bedingten Anforderungen ergänzt, angepasst und weiterentwickelt. Auf der Grundlage einer Auswertung relevanter laufender Bundes- und Länderprogramme werden wesentliche Wirkungen des Klimawandels identifiziert, die datenliefernden Programme zugeordnet und Auswertungen vorgeschlagen. Zusätzlich werden Datenquellen beschrieben, deren Nutzung weitergehende Betrachtungen ermöglichen. ErgebnisseIn einer Übersichtstabelle werden Monitoring-Programme auf Bundes- und Länderebene systematisiert und hinsichtlich ihrer Bedeutung für die Bewertung von Klimafolgen auf die belebte Umwelt dargestellt. Eine Übersicht über Datenquellen sowie eine Darstellung erster Erkenntnisse aus der Auswertung vorliegender Daten belegen die Relevanz des vorgeschlagenen Verfahrens. Der erkennbare Forschungs- und Entwicklungsbedarf wird umrissen und Vorschläge für eine Optimierung des Daten- und Methodenaustausches benannt. Beispiele zur Anwendung und Vertiefung der Thematik sowie Anregungen zur Weiterentwicklung der Methodik und zum Schließen von Kenntnislücken werden in Folgepublikationen aufgezeigt. DiskussionAuf der Basis des Klima-Biomonitorings kann das Ausmaß der durch den Klimawandel bereits eingetretenen Veränderungen beschrieben sowie Szenarien und Prognosen zu den Auswirkungen von Klimaveränderungen erstellt werden. Weiterhin ist es möglich, die sekundären Wirkungen des Klimawandels, insbesondere die Auswirkungen der Maßnahmen zur Anpassung an den Wandel, mithilfe der Bioindikation auf ihre Wirksamkeit zu prüfen. Für einige Klima-Bioindikatoren ist der kausale Zusammenhang zwischen Klimawandel und Reaktion bereits belegt (zum Beispiel die Frühjahrsphasen in der Pflanzenphänologie), in anderen Fällen müssen noch Methoden zur Unterscheidung zwischen Klimawirkungen und anderen Wirkfaktoren entwickelt werden. Die Erkenntnisse aus dem Klima-Biomonitoring sollen Grundlage für entsprechende Handlungen sein, sodass geeignete Anpassungsstrategien und gleichzeitig Maßnahmen zur Vermeidung oder zur Verminderung der Effekte eingeleitet werden können. Zugleich sollen eine angemessene Politikberatung, eine Information der Öffentlichkeit und die Erfüllung entsprechender Berichtspflichten erfolgen. Schlussfolgerungen:Klima-Biomonitoring ist eine geeignete Methode, um klimainduzierte Veränderungen in besonders empfindlichen Gebieten in Deutschland mit ihren Lebensräumen, Lebensgemeinschaften und Arten darzustellen. Erste Auswertungen zeigen, dass bereits Wirkungen des Klimawandels auf die belebte Umwelt nachweisbar sind. Hierbei liefert die Pflanzenphänologie seit vielen Jahren wertvolle Hintergrunddaten. Eine Verschneidung dieser Hintergrunddaten mit Daten aus anderen geeigneten Monitoring-Programmen und weiteren Informationen (zum Beispiel Geobasisdaten) ermöglicht es, diese Erkenntnisse zu ergänzen. Damit ist die Ermittlung und Bewertung von klimainduzierten Wirkungen auch im Bereich der Ausbreitung von Krankheitsüberträgern und -erregern und anderer Phänomene sowie der Bewertung von Maßnahmen möglich. Empfehlungen und PerspektivenEine abgestimmte Anwendung der Methodik in allen Bundesländern und beim Bund, eine Verbesserung des Daten- und Methodenaustausches, die Identifikation, Erschließung und Nutzung weiterer Datenquellen, die Weiterentwicklung der Methodik und eine Publikation weiterer Erkenntnisse werden empfohlen. Es ist davon auszugehen, dass sich das Klima-Biomonitoring wegen seiner Vorteile als Methode zur Erhebung von Klimafolgen für die belebte Umwelt auch international etablieren wird.     

Modeling the dynamic habitat and breeding population of Southwestern Willow Flycatcher

To aid in the management and conservation of Southwestern Willow Flycatcher (Empidonax traillii extimus, hereafter “Flycatcher”), we developed numerous models of flycatcher breeding habitat at Roosevelt Lake, AZ. For model development and testing, we compiled 10 years of flycatcher territory data that were obtained from intensive fieldwork between 1996 and 2005. We identified riparian vegetation annually in the project area from Landsat Thematic Mapper images, and extracted floodplain features from a digital elevation model. We created a novel class of temporal (i.e., multiyear) variables by characterizing the stability and variability in breeding habitat over a 6-year time interval. We used logistic regression to determine associations between environmental variables and flycatcher territory occurrence, and to test specific hypotheses. We mapped the probability of territory occurrence with a GIS and determined model accuracies with a classification table and a 10-year population database. Environmental features that were associated with breeding flycatchers included floodplain size, proximity to water, and the density, heterogeneity, age and stability of riparian vegetation. Our best model explained 79% of the variability in the flycatcher breeding population at Roosevelt Lake. The majority of predicted flycatcher habitat formed between 1996 and 2004 on an exposed lakebed ～3 years after water levels receded during a prolonged drought. A high correlation between annual reservoir levels and predicted breeding habitat (r = ?0.82) indicates that we can create and manage habitat for conservation purposes. Our predictive models quantify and assess the relative quality of flycatcher breeding habitat remotely, and can be used to evaluate the effectiveness of habitat restoration activities. Numerous techniques we developed can be used to characterize riparian vegetation and patch dynamics directly off of satellite imagery, thereby increasing its utility for conservation purposes.     

New evidence for habitat-specific selection in Wadden Sea Zostera marina populations revealed by genome scanning using SNP and microsatellite markers

Eelgrass Zostera marina is an ecosystem-engineering species of outstanding importance for coastal soft sediment habitats that lives in widely diverging habitats. Our first goal was to detect divergent selection and habitat adaptation at the molecular genetic level; hence, we compared three pairs of permanently submerged versus intertidal populations using genome scans, a genetic marker-based approach. Three different statistical approaches for outlier identification revealed divergent selection at 6 loci among 46 markers (6 SNPs, 29 EST microsatellites and 11 anonymous microsatellites). These outlier loci were repeatedly detected in parallel habitat comparisons, suggesting the influence of habitat-specific selection. A second goal was to test the consistency of the general genome scan approach by doubling the number of gene-linked microsatellites and adding single nucleotide polymorphism (SNP) loci, a novel marker type for seagrasses, compared to a previous study. Reassuringly, results with respect to selection were consistent among most marker loci. Functionally interesting marker loci were linked to genes involved in osmoregulation and water balance, suggesting different osmotic stress, and reproductive processes (seed maturation), pointing to different life history strategies. The identified outlier loci are valuable candidates for further investigation into the genetic basis of natural selection.     

Chemical speciation and bioaccessibility of lead in surface soil and house dust,Lavrion urban area,Attiki, Hellas

In the Lavrion urban area study, Hellas, a five-step sequential extraction method was applied on samples of ‘soil’ (n = 224), affected by long-term mining and metallurgical activities, and house dust (n = 127), for the purpose of studying the potential bioaccessibility of lead and other metals to humans. In this paper, the Pb concentrations in soil and house dust samples are discussed, together with those in rocks and children’s blood. Lead is mainly associated with the carbonate, Fe–Mn oxides and residual fractions in soil and house dust. Considering the very low pH of gastric fluids (1–3), a high amount of metals, present in soil (810–152,000 mg/kg Pb) and house dust (418–18,600 mg/kg Pb), could be potentially bioaccessible. Consequently, children in the neighbourhoods with a large amount of metallurgical processing wastes have high blood-Pb concentrations (5.98–60.49 μg/100 ml; median 17.83 μg/100 ml; n = 235). It is concluded that the Lavrion urban and sub-urban environment is extremely hazardous to human health, and the Hellenic State authorities should urgently tackle this health-related hazard in order to improve the living conditions of local residents.