EVALUATION OF INHOMOGENEITIES IN HISTOLOGICAL STRUCTURES (CARTILAGE, RETINA)

This paper investigates histological tissues by means of image analysis and spatial statistics. For the quantification of cell frequencies and accumulations two statistical characteristics, intensity function and cluster density, are suggested. The samples are histological sections of human articular cartilage and human retina considered in view of changes during the ageing process. The articular cartilage is characterized by continuous changes of both functions, the cell intensity as well as the clusterization. In contrast, the retina is a trilaminar structure formed in the early embryonic stage without changes by ageing

National nitrogen budget for Germany

Emissions of reactive nitrogen (N-r) give rise to a wide range of environmental problems. Nitrogen budgets for various systems and on different scales are an established tool to quantify the sources and fate of N-r. The national nitrogen budget (NNB) for Germany calculates the nitrogen flows for eight pools: Atmosphere, Energy and Fuels, Material and Products in Industry, Humans and Settlements, Agriculture, Forest and Semi-natural Vegetation, Waste, and Hydrosphere, as well as for the transboundary N-flows. In Germany, in total 6,275 kt N-r a(-1) has been introduced into the nitrogen cycle annually (mean 2010 to 2014), of which 43% stem from ammonia synthesis. Domestic extraction and import of nitrogenous fossil fuels (lignite, coal, crude oil) releases another 2,335 kt N-r a(-1). Import of food, feed and materials contributes 745 kt N-r a(-1), while biological N fixation converts 308 kt N-r a(-1) into organically bound nitrogen. In terms of N-r sinks, the combustion and denoxing of fuels and the refining of crude oil converts 2,594 kt N-r a(-1) to N-2. In waters, soils, and wastewater treatment plants, denitrification leads to the release of 1,107 kt N-r a(-1) as N-2. Via the atmosphere and hydrosphere, Germany exports 755 kt N-r a(-1) to neighbouring countries and into coastal waters. On balance, Germany releases 1,627 kt N-r a(-1) annually to the environment. However, the NNB as a whole and the individual pool balances involve substantial uncertainties, which have to be considered when interpreting the results

Nitrogen in Current European Policies

Europe, and especially the European Union (EU), has many governmental policy ¿ measures aimed at decreasing unwanted reactivenitrogen (N r ) emissions from combustion, agriculture and urban wastes. Many of these policy measures have an ¿eff ects-basedapproach¿, and focus on single N r compounds, single sectors and either on air or waters.¿ Th is chapter addresses the origin, objectives and targets of EU policy measures related to Nr emissions, considers which instrumentsare being used to implement the policies and briefl y discusses the eff ects of the policy measures.Approaches¿ Th e chapter starts with a brief description of the basic elements of governmental policy measures.¿ A review of the main international conventions and EU policies related to emissions of Nr to air and water is then provided.¿ Finally the chapter provides a semi-quantitative assessment of the eff ectiveness and effi ciency of European policy measures.Key fi ndings/state of knowledge¿ International conventions and other treaties have played a key role in raising awareness and establishing policy measures for Nr emissionsabatement in EU through so-called Directives and Regulations.¿ Th ere are many diff erent EU Directives, oft en addressing individual Nr compounds from individual sectors (e.g. NOx emissions fromcombustion; NH 3 emissions from agriculture, pollution of groundwater and surface water by nitrates from agriculture, discharge oftotal nitrogen from urban sewage to surface waters).¿ Many EU Directives have been revised following review and evaluation. Th ere are increasing eff orts to cluster single EU Directives intolarger Framework Directives.¿ Compliance with, and eff ectiveness of, the Directives diff ers between sectors; it decreases in the order (i) reducing NO x emissions fromcombustion sources, (ii) reducing nitrogen (and especially Phosphorus) discharges to waters from industries and households, and (iii)reducing NH 3 emissions and NO 3 leaching from agriculture.¿ Th ere is not much literature on the diff erences in the eff ectiveness and effi ciencies of Directives; a number of factors seem to be involvedin eff ectiveness and effi ciency, but these have not yet been analysed in a coherent manner.Major uncertainties/challenges¿ Th ere is a huge diversity in N r emission sources and pathways, while the number of policy instruments is limited. Th ere is need to fi ndthe optimal mix of policy instruments targeted to the emission sources as well as the stakeholders involved.¿ It has been indicated that some EU Directives addressing emissions of nitrogen compounds from specifi c sources have antagonisticeff ects. Th e magnitude of these eff ects is not yet well known.¿ Th ere is a delay in the environmental and ecological responses following the introduction of Directives; these are due to legislativedelays, lack of enforcement and control, constraints in practice and because of biogeochemical hysteresis eff ects; these eff ects are notyet well understood quantitatively.¿ In general, only modest reductions in Nr emissions from agriculture have been achieved to date; this refl ects the need for more eff ectiveand effi cient policy measures and/or greater enforcement of current policies.Recommendations¿ To examine further the diff erences between sectors of the factors that contribute to the eff ectiveness and effi ciency of policy measuresfor the abatement of N r emissions.¿ T o explore further the eff ectiveness and effi ciency of more integrated N management and integrated policy measures for the abatementof adverse impacts of N r emissions.JRC.DDG.H.2-Climate change and air qualit

Nitrogen deposition in appropriate assessment under Article 6 (3) of the Habitats Directive: Critical Load, thresholds of insignificant impacts, and bagatelle

Die Ermittlung und Bewertung der Auswirkungen von Stickstoffeinträgen in der FFH-Verträglichkeitsprüfung ist in Deutschland seit fast zehn Jahren Gegenstand einer intensiven Fachdiskussion. Zuletzt hat sich ein Forschungsprojekt im Auftrag der Bundesanstalt für Straßenwesen (BASt) mit dieser Frage beschäftigt und eine Fachkonvention für den Projekttyp Straße erarbeitet. Diese Fachkonvention, die auch auf andere Projekttypen übertragbar ist, basiert grundsätzlich auf dem Maßstab der Critical Loads zur Beschreibung der Empfindlichkeit von FFH-Lebensräumen gegenüber Stickstoffeintrag. Liegt die gebietsspezifische Gesamtbelastung mit Stickstoffeinträgen über dem standort- und vegetationstypspezifisch zu ermittelnden Critical Load, so wird für die FFH-Verträglichkeitsprüfung ein mehrstufiges Schwellenwertkonzept zur Bestimmung von irrelevanten bzw. bagatellhaften Zusatzbelastungen empfohlen: Unterschieden wird ein vorhabenbezogenes absolutes Abschneidekriterium von 0,3 kg N ha-1a-1 und eine rezeptorbezogene Bagatellschwelle von 3% des jeweiligen Critical Loads. Beide Schwellenwerte sind als sehr niedrig und der Zielsetzung der FFH-Richtlinie entsprechend vorsorgeorientiert einzustufen.Mit dem Bewertungsansatz werden alle Anforderungen, die sich aus den fachlichen und rechtlichen Maßstäben für die FFH-Verträglichkeitsprüfung ergeben, berücksichtigt. Zugleich handelt es sich um einen praxistauglichen Bewertungsansatz, der auch dem Grundsatz der Verhältnismäßigkeit Rechnung trägt. Das vorhabenbezogene Abschneidekriterium soll für jedes zu genehmigende Vorhaben gelten. Für die Größenordnung von 0,3kg N ha-1a-1 für den vorhabenbezogenen Stickstoffeintrag in ein FFH-Gebiet sprechen verschiedene Argumente: Einträge in dieser Größenordnung liegen deutlich unterhalb der messtechnischen Erfassbarkeit und deutlich unterhalb jeder bekannten Schwelle von Zusatzbelastungen, die negative Wirkungen für die Biodiversität auslösen können; unterhalb dieser Größenordnung ist eine Ermittlung von Belastungen und Beeinträchtigungen mit derzeit verfügbaren Modellen und Eingangsdaten auch aufgrund der Unsicherheiten und fehlenden statistischen Signifikanz nicht mehr sinnvoll möglich. Zusatzbelastungen eines Vorhabens in dieser Größenordnung stellen somit lediglich ein theoretisches Risiko dar und können keine erheblichen Beeinträchtigungen im Sinne der FFH-RL auslösen. Somit können auch nur diejenigen projektbezogenen Zusatzbelastungen, die oberhalb dieses Abschneidekriteriums liegen, für eine kumulative Prüfung mit weiteren Projekten und deren gemeinsamer Wirkung geprüft werden. Die Bagatellschwelle von 3% des Critical Loads wird demgegenüber gebietsbezogen angewendet und kann daher auch durch das Zusammenwirken mehrerer einzelner Vorhaben überschritten werden. Die Anwendung soll unabhängig von der Höhe der Überschreitung der Critical Loads in der Gesamtbelastung möglich sein. Die Bagatellschwelle ist an der spezifischen Stickstoffempfindlichkeit der FFH Lebensräume, die durch die Critical Loads vorsorgeorientiert beschrieben wird, ausgerichtet. Eine Auswertung der Ergebnisse der Wirkungsforschung, insbesondere zu Randeffekten entlang von Straßen, hat ergeben, dass der Wert von 3% des maßgeblichen Critical Loads sicher unterhalb von feststellbaren negativen Wirkungen auf den Erhaltungszustand von FFH-Lebensräumen liegt.For the last ten years impacts from nitrogen deposition within appropriate assessments has been a controversial issue discussed by many experts in Germany. More recently results from a R&D project funded by the Federal Highway Research Institute (BASt) have been published to establish a method on the assessment for road projects. Adverse effects are assessed in a staged approach based on the concept of critical loads: if total environmental Deposition is lower than critical loads of the most sensitive feature of the site, no likely significant effects have to be expected. Project contributions up to a de-minimis value of 0.3kg N ha-1y-1 are considered as being too small to be measurable. Neither could nitrogen deposition of up to this value be detected in the field nor could damages be attributed to projects contributing such small amounts. Project contributions lower than the proposed threshold thus exert only hypothetical risks that do not justify or even demand refusals of Project under Article 6.3. Only project contributions above the cut off criterion have to be considered within an appropriate assessment in combination with other projects. With view on the protected site another threshold of 3 % of the critical load is applied that can be exceeded not only by single projects but also in combination. Its application does not depend on background deposition. It depends on the specific sensitivity of the habitat precautionarily described by critical loads. Examination of scientific results on the effects, particularly along roads has shown that a value of 3% of a particular critical load clearly lies below detectable adverse effects on the conservation status of natura 2000 habitats. Both thresholds are very low and thus in line with the precautionary approach prescribed by the Habitats Directive. The assessment approach encompasses legal as well as scientific confidence. It also adheres to the principle of proportionality and has proven to be functional in practice. As nitrogen inputs up to 0.3 kg N ha-1y-1 cannot be realistically attributed to a particular project, they should rather be described as diffuse part of the background deposition. High background deposition in turn should be lowered by the most efficient measures to stay in accordance with the requirement under the Habitats Directive to avoid deterioration. Very small project contributions as accepted by the proposed process will not constitute an obstacle for this

A National Nitrogen Target for Germany

The anthropogenic nitrogen cycle is characterized by a high complexity. Different reactive nitrogen species (NH3, NH4+, NO, NO2, NO3−, and N2O) are set free by a large variety of anthropogenic activities and cause numerous negative impacts on the environment. The complex nature of the nitrogen cycle hampers public awareness of the nitrogen problem. To overcome this issue and to enhance the sensitivity for policy action, we developed a new, impact-based integrated national target for nitrogen (INTN) for Germany. It is based on six impact indicators, for which we derived the maximum amount of nitrogen losses allowed in each environmental sector to reach related state indicators on a spatial average for Germany. The resulting target sets a limit of nitrogen emissions in Germany of 1053 Gg N yr−1. It could serve as a similar means on the national level as the planetary boundary for reactive nitrogen or the 1.5 °C target of the climate community on the global level. Taking related uncertainties into account, the resulting integrated nitrogen target of 1053 Gg N yr−1 suggests a comprehensible INTN of 1000 Gg N yr−1 for Germany. Compared to the current situation, the overall annual loss of reactive nitrogen in Germany would have to be reduced by approximately one-third

A National Nitrogen Target for Germany

The anthropogenic nitrogen cycle is characterized by a high complexity. Different reactive nitrogen species (NH3, NH4+, NO, NO2, NO3−, and N2O) are set free by a large variety of anthropogenic activities and cause numerous negative impacts on the environment. The complex nature of the nitrogen cycle hampers public awareness of the nitrogen problem. To overcome this issue and to enhance the sensitivity for policy action, we developed a new, impact-based integrated national target for nitrogen (INTN) for Germany. It is based on six impact indicators, for which we derived the maximum amount of nitrogen losses allowed in each environmental sector to reach related state indicators on a spatial average for Germany. The resulting target sets a limit of nitrogen emissions in Germany of 1053 Gg N yr−1. It could serve as a similar means on the national level as the planetary boundary for reactive nitrogen or the 1.5 °C target of the climate community on the global level. Taking related uncertainties into account, the resulting integrated nitrogen target of 1053 Gg N yr−1 suggests a comprehensible INTN of 1000 Gg N yr−1 for Germany. Compared to the current situation, the overall annual loss of reactive nitrogen in Germany would have to be reduced by approximately one-third

Research meetings must be more sustainable

Scientific meetings should be organized in the spirit of responsible consumption and production, including the prioritization of plant-based meals for reduced nitrogen loss. The Cercedilla Manifesto indicates how

Integrating Nitrogen Fluxes at the European Scale

Environmental problems related to nitrogen concern all economic sectors and impact all media: atmosphere, pedosphere, hydrosphere and anthroposphere. Therefore, the integration of fl uxes allows an overall coverage of problems related to reactive nitrogen (N r ) in the environment, which is not accessible from sectoral approaches or by focusing on specifi c media. This chapter presents a set of high resolution maps showing key elements of the N fl ux budget across Europe, including N2 and Nr fluxes. Comparative nitrogen budgets are also presented for a range of European countries, highlighting the most effi cient strategies for mitigating Nr problems at a national scale. A new European Nitrogen Budget (EU-27) is presented on the basis of state-of-the-art Europe-wide models and databases focusing on diff erent segments of Europe’s society. From c . 18 Tg Nr yr−1 input to agriculture in the EU-27, only about 7 Tg N r yr− 1 fi nd their way to the consumer or are further processed by industry. Some 3.7 Tg N r yr −1 is released by the burning of fossil fuels in the EU-27, whereby the contribution of the industry and energy sectors is equal to that of the transport sector. More than 8 Tg N r yr −1 are disposed of to the hydrosphere, while the EU-27 is a net exporter of reactive nitrogen through atmospheric transport of c . 2.3 Tg N r yr−1. The largest single sink for Nr appears to be denitrifi cation to N 2 in European coastal shelf regions (potentially as large as the input of mineral fertilizer, about 11 Tg N yr –1 for the EU-27); however, this sink is also the most uncertain, because of the uncertainty of N r import from the open ocean. Major uncertainties: National nitrogen budgets are diffi cult to compile using a large range of data sources and are currently available only for a limited number of countries. Modelling approaches have been used to fi ll in the data gaps in some of these budgets, but it became obvious during this study that further research is needed in order to collect necessary data and make national nitrogen budgets inter-comparable across Europe. In some countries, due to inconsistent or contradictory information coming from diff erent data sources, closure of the nitrogen budget was not possible. Recommendations: • The large variety of problems associated with the excess of Nr in the European environment, including adverse impacts, requires an integrated nitrogen management approach that would allow for creation and closure of N budgets within European environments. • Development of nitrogen budgets nationwide, their assessment and management could become an eff ective tool to prioritize measures and prevent unwanted side effects.JRC.DDG.H.2-Climate change and air qualit