Leistungen der ökologischen Landwirtschaft zur Reduzierung des Erosions- und Hochwasserrisikos im Vergleich zu konventioneller Bewirtschaftung – Ergebnisse einer systematischen Vergleichsstudie

Niederschlagsveränderungen durch den Klimawandel führen zu einem erhöhten Risiko für Erosion und Hochwasser in Deutschland. Aufgrund von guter Bodenbedeckung und einer verbesserten Bodenstruktur hat der ökologische Landbau ein hohes Erosions- und Hochwasserschutzpotenzial, allerdings ist die Datenlage unzureichend. Daten aus 43 Studien wurden für 7 Parameter qualitativ ausgewertet. Die Vergleichspaare wurden in die Kategorien „kleiner“, „größer“ bzw. „gleich“ eingeordnet, je nachdem, ob der untersuchte Parameter unter ökologischer Bewirtschaftung besser, schlechter oder ähnlich wie unter konventioneller Bewirtschaftung ausgewiesen wurde. Ergebnisse für bodenstrukturelle Parameter weisen auf eine niedrigere Erodierbarkeit der ökologisch bewirtschafteten Böden hin. Der Bewirtschaftungsfaktor (C-Faktor) aus der ABAG war auch niedriger für die ökologischen Varianten. Dementsprechend war die Infiltration höher und der Oberflächenabfluss und Bodenabtrag niedriger in den ökologischen Systemen. Eine Vergleichbarkeitsanalyse der Studien ist nötig

Elements for the Expected Mechanisms on Reduced Emissions from Deforestation and Degradation, REDD under UNFCCC

Carbon emissions from deforestation and degradation account for 20% of the global anthropogenic emissions (IPCC WG I, 2007). Since the eleventh session of the Conference of the Parties to the United Nations Convention on Climate Change (UNFCCC) in December 2005, strategies and incentives for Reduced Emissions from Deforestation and Degradation (REDD) have emerged as one of the most attended negotiation items. It is not easy to build an international agreement on the role of REDD in a future climate change regime, but now we are close to an achievable historical decision on the future of forests: the Bali mandate on REDD. In this paper we suggest some elements for an effective long-term implementation of a REDD mechanism under the UNFCCC and for closing gaps in the forestry accounting system. These elements are related both to ecological and political processes, reflecting some of the most critical and debated negotiation points. The proposed elements are: a) carbon (C) losses from forests; b) incentives for all stages of reducing emissions, stabilizing and maintaining forest C stocks; c) national approach; d) data availability at national scale; e) conservativeness approach for carbon accounting.JRC.H.2-Climate chang

EU Peatlands: Current Carbon Stocks and Trace Gas Fluxes

Peatlands in Europe has formed a significant sink for atmospheric CO2 since the last glacial maximum. Currently they are estimated to hold ca. 42 Gt carbon in the form of peat and are therefore a considerable component in the European carbon budget. Due to the generally wet soil conditions in peatlands they are also significant emitters of the strong greenhouse gas (GHG) methane (CH4) and in some cases also of nitrous oxide (N2O). The EU funded CarboEurope-GHG Concerted Action attempts to develop a reliable and complete greenhouse gas budget for Europe and this report aims to provide a review and synthesis of the available information about GHG exchanges in European peatlands and their underlying processes. A best estimate for all the European countries shows that some are currently sinks for atmospheric CO2 while others are sources. In contrast, for CH4 and N2O, only the sources are relevant. Whilst some countries are CO2 sinks, all countries are net GHG emitters from peatlands. The results presented, however, carry large uncertainties, which cannot be adequately quantified yet. One outstanding uncertainty is the distribution of land use types, particular in Russia, the largest European peat nation. The synthesis of GHG exchange, nevertheless, indicates some interesting features. Russia hosts an estimated 41% of European peatlands and contributes most to all GHG exchanges (CO2: 25%, CH4: 52%, N2O: 26%, Total: 37%). Germany is the second-largest emitter (12% of European total) although it contains only 3.2% of European peatlands. The reason is the use of most of the peatland area for intensive cropland and grassland. The largest CO2 emitters are countries with large agricultural peatland areas (Russia, Germany, Belarus, Poland), the largest N2O emitters are those with large agricultural fen areas (Russia, Germany, Finland). In contrast, the largest CH4 emitters are concentrated in regions with large areas of intact mires, namely Russia and Scandinavia. High average emission densities above 3.5 t C-equiv. ha-1 are found in the Southeast Mediterranean, Germany and the Netherlands where agricultural use of peatlands is intense. Low average emission densities below 0.3 t C-equiv. ha-1 occur where mires and peatland forests dominate, e.g. Finland and the UK. This report concludes by pointing at key gaps in our knowledge about peatland carbon stocks and GHG exchanges which include insufficient basic information on areal distribution of peatlands, measurements of peat depth and also a lack of flux datasets providing full annual budgets of GHG exchanges

Nitrogen mineralization and gaseous nitrogen losses from waterlogged and drained organic soils in a black alder (<i>Alnus glutinosa</i> (L.) Gaertn.) forest

Black alder (<i>Alnus glutinosa</i> (L.) Gaertn.) forests on peat soils have been reported to be hotspots for high nitrous oxide (N₂O) losses. High emissions may be attributed to alternating water tables of peatlands and to the incorporation of high amounts of easily decomposable nitrogen (N) into the ecosystem by symbiotic dinitrogen (N₂)-fixation of alder trees. Our study addressed the question to what extent drainage enhances the emissions of N₂O from black alder forests and how N turnover processes and physical factors influence the production of N₂O and total denitrification. The study was conducted in a drained black alder forest with variable groundwater tables at a southern German fen peatland. Fluxes of N₂O were measured using the closed chamber method at two drained sites (D-1 and D-2) and one undrained site (U). Inorganic N contents and net N mineralization rates (NNM) were determined. Additionally a laboratory incubation experiment was carried out to investigate greenhouse gas and N₂ fluxes at different temperature and soil moisture conditions. Significantly different inorganic N contents and NNM rates were observed, which however did not result in significantly different N₂O fluxes in the field but did in the laboratory experiment. N₂O fluxes measured were low for all sites, with total annual emissions of 0.51 ± 0.07 (U), 0.97 ± 0.13 (D-1) and 0.93 ± 0.08 kg N₂O–N ha⁻¹ yr^&minus;1 (D-2). Only 37% of the spatiotemporal variation in field N₂O fluxes could be explained by peat temperature and groundwater level, demonstrating the complex interlinking of the controlling factors for N₂O emissions. However, temperature was one of the key variables of N₂O fluxes in the incubation experiment conducted. Increasing soil moisture content was found to enhance total denitrification losses during the incubation experiment, whereas N₂O fluxes remained constant. At the undrained site, permanently high groundwater level was found to prevent net nitrification, resulting in a limitation of available nitrate (NO₃^&minus;) and negligible gaseous N losses. N₂O flux rates that were up to four times higher were measured in the incubation experiment. They reveal the potential of high N₂O losses under changing soil physical conditions at the drained alder sites. The high net nitrification rates observed and high NO₃^&minus; contents bear the risk of considerable NO₃^&minus; leaching at the drained sites

The relevance of particulate organic carbon (POC) for carbon composition in the pore water of drained and rewetted fens of the "Donauried" (South-Germany)

International audienceNumerous studies have dealt with carbon (C) concentrations in Histosols, but there are no studies quantifying the relative importance of all individual C components in pore waters. For this study, measurements were made of all the carbon components (i.e., particulate organic carbon, POC; dissolved organic carbon, DOC; dissolved inorganic carbon, DIC; dissolved methane, CH4) in the soil pore water of a calcareous fen under three different water management regimes (re-wetted, deeply and moderately drained). Pore water was collected weekly or biweekly (April 2004 to April 2006) at depths between 10 and 150 cm. The main results obtained were: (1) DIC (94?280 mg C l?1) was the main C-component. (2) POC and DOC concentrations in the pore water (14?125 mg C l?1 vs. 41?95 mg C l?1) were pari passu. (3) Dissolved CH4 was the smallest C component (0.005?0.9 mg C l?1). Interestingly, about 30% of the POM particles were colonized by microbes indicating that they are active in the internal C transfer in the soil profile ("C-Shuttles"). Consequently, it was concluded that POC is at least as important as DOC for internal soil C turnover. There is no reason to assume significant biochemical differences between POC and DOC as they only differ in size. Therefore, both POC and DOC fractions are essential components of C budgets of peatlands. Furthermore dissolved CO2 in all forms of DIC apparently is an important part of peatland C-balances

Berechnung von gas- und partikelförmigen Emissionen aus der deutschen Landwirtschaft 1990 - 2011. Report zu Methoden und Daten (RMD) Berichterstattung 2013

In Europe, gaseous and particulate emissions from agriculture have been subject to both national and international regulations, as they adversely affect the energy dynamics of the atmosphere (physical climate), the formation of tropospheric and the destruction of stratospheric ozone, the amount of formation of secondary aerosols, terrestrial and aquatic ecosystems due to atmospheric inputs of acidity and nutrients (acidification and eutrophication), human health and welfare and reduce atmospheric visibility. These internation regulations (protocols etc.) are the UN Framework Convention on Climate Change (UNFCCC5), the UNECE Convention on Long-Range Transboundary Air Pollution (CLRTAP6), and within the European Union the Directive of the European Parliament and of the Council on national emission ceilings for certain atmospheric pollutants (NEC Directive7). The forementioned conventions require annual calculations of the emissions of the respective gases and air pollutants. The results have to be documented in an emission inventory and to be reported to the organisations in charge. The German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) is responsible for the entire German emission reporting. However, the sector “Agriculture” is dealt with under the aegis of the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV). BMELV has charged the Institute for Climate-Smart Agriculture (AK) (the former Insitute of Agricultural Climate Research) of the Johann Heinrich von Thünen-Institut (TI) with the establishment of the annual agricultural emission inventory where only emissions from agricultural animal husbandry and from managed agricultural soils are regarded as agricultural emissions.Deutschland hat umfangreiche internationale Verpflichtungen zur Emissionsminderung für Treibhausgase und Luftschadstoffe übernommen. Hierzu gehören insbesondere im Rahmen der Vereinten Nationen die Konventionen zur Vermeidung und Verminderung weitreichender grenzüberschreitender Luftverunreinigungen (UNECE CLRTAP mit seinen acht Protokollen), die Klimarahmenkonvention (UNFCCC) und das Kyoto-Protokoll, im europäischen Kontext die Richtlinien zur Einhaltung nationaler Emissionsobergrenzen (NEC) sowie der europäische Beobachtungsmechanismus für Treibhausgasemissionen und die Umsetzung des Kyoto-Protokolls. Zur Erfolgskontrolle dieser Verpflichtungen sind jährlich detaillierte Inventare nationaler Emissionen zu berechnen und international zu berichten. Weitere Verpflichtungen bestehen zur Berichterstattung von anlagenbezogene Emissionsdaten, wie z. B. das europäische Schadstoffregister PRTR. Die Zielstellungen der internationalen Regelungen bestehen in der Vermeidung bzw. Verminderung der Effekte der Klimaänderung, Gewährleistung des Schutzes der Ozonschicht, Vermeidung von Versauerung und Eutrophierung in Ökosystemen, Bekämpfung der Entstehung von bodennahem Ozon, Reduzierung der Feinstaubbelastungen, Einhaltung von Luftqualitätsstandards, Vermeidung gefährlicher (toxischer) Luftbelastungen, Information der Öffentlichkeit über den Umweltzustand. Das im Februar 2005 in Kraft getretene Kyoto-Protokoll verbindet zusätzlich und erstmalig umweltstrategische Ziele und flexible ökonomische Instrumente (Emissionshandel sowie gemeinsame Projekte mit Entwicklungsländern bzw. entwickelten Industrienationen) als weiteren Weg, die Ziele der Verpflichtungen zu erreichen. Durch die damit erfolgte indirekte ökonomische und monetäre Bewertung der Emissionen sind weitere umfangreiche Anforderungen an die Genauigkeit der Emissionsermittlung gestellt. Diese bestehen in der Forderung nach Transparenz der Ermittlung und Berichterstattung, Vergleichbarkeit der Ergebnisse mit denen anderer Länder, Konsistenz der berichteten Emissionszeitreihen, Vollständigkeit der Einbeziehung aller Quellen und Senken in das Inventar sowie die Bestimmung der Genauigkeit der Emissionen

The carbon budget of terrestrial ecosystems at country-scale – a European case study

We summed estimates of the carbon balance of forests, grasslands, arable lands and peatlands to obtain country-specific estimates of the terrestrial carbon balance during the 1990s. Forests and grasslands were a net sink for carbon, whereas croplands were carbon sources in all European countries. Hence, countries dominated by arable lands tended to be losing carbon from their terrestrial ecosystems, whereas forest-dominated countries tended to be sequestering carbon. In some countries, draining and extraction of peatlands caused substantial reductions in the net carbon balance. Net terrestrial carbon balances were typically an order of magnitude smaller than the fossil fuel-related carbon emissions. Exceptions to this overall picture were countries where population density and industrialization are small. It is, however, of utmost importance to acknowledge that the typically small net carbon balance represents the small difference between two large but opposing fluxes: uptake by forests and grasslands and losses from arable lands and peatlands. This suggests that relatively small changes in either or both of these large component fluxes could induce large effects on the net total, indicating that mitigation schemes should not be discarded a priori. In the absence of carbon-oriented land management, the current net carbon uptake is bound to decline soon. Protecting it will require actions at three levels; a) maintaining the current sink activity of forests, b) altered agricultural management practices to reduce the emissions from arable soils or turn into carbon sinks and c) protecting current large reservoirs (wetlands and old forests), since carbon is lost more rapidly than sequestered

Berechnung von gas- und partikelförmigen Emissionen aus der deutschen Landwirtschaft 1990-2014: Report zu Methoden und Daten (RMD) Berichterstattung 2016

The report at hand (including a comprehensive annex of data) serves as additional document to the National Inventory Report (NIR) on the German green house gas emissions and the Informative Inventory Report (IIR) on the German emissions of air pollutants (especially ammonia). The report documents the calculation methods used in the German agricultural inventory model GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2016 for the years 1990 - 2014. In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy crops. As required by the guidelines, emissions from activities preceding agriculture, from the use of energy and from land use change are reported elsewhere in the national inventories. The calculation methods are based in principle on international guidelines for emission reporting and have been continuingly improved during the past years. In particular, these improvements concern the calculation of energy requirements, feeding and the N balance of the most important animal categories. In addition, technical measures such as air scrubbing (mitigation of ammonia emissions) and digestion of animal manures mitigation of emissions of methane and loughing gas) have been taken into account [...].Der vorliegende Berichtsband einschließlich des umfangreichen Datenanhangs dient als Begleitdokument zum National Inventory Report (NIR) über die deutschen Treibhausgas-Emissionen und zum Informative Inventory Report (IIR), über die deutschen Schadstoffemissionen (insbesondere Ammoniak). Er dokumentiert die im deutschen landwirtschaftlichem Inventarmodell GASEM integrierten Berechnungsverfahren sowie die Eingangsdaten, Emissionsergebnisse und Unsicherheiten der Berichterstattung 2016 für die Jahre 1990 bis 2014. Der Bereich Landwirtschaft umfasst dabei die Emissionen aus der Tierhaltung und der Nutzung landwirtschaftlicher Böden sowie aus der Vergärung von Energiepflanzen. Emissionen aus dem Vorleistungsbereich, aus der Nutzung von Energie sowie Landnutzungsänderungen werden den Regelwerken entsprechend an anderer Stelle in den nationalen Inventaren berichtet. Die Berechnungsverfahren beruhen in erster Linie auf internationalen Regelwerken zur Emissionsberichterstattung und wurden in den vergangenen Jahren beständig weiterentwickelt. Letzteres betrifft im Wesentlichen die Berechnung des Energiebedarfs, der Fütterung und der tierischen N-Bilanz bei den wichtigen Tierkategorien. Zusätzlich wurden technische Maßnahmen wie Abluftreinigung (Minderung von Ammoniakemissionen) und die Vergärung von Wirtschaftsdünger (Minderung von Methan- und Lachgasemissionen) berücksichtigt [...]

Berechnung von gas- und partikelförmigen Emissionen aus der deutschen Landwirtschaft 1990-2013: Report zu Methoden und Daten (RMD) Berichterstattung 2015

The report at hand (including a comprehensive annex of data) serves as additional document to the National Inventory Report (NIR) on the German green house gas emissions and the Informative Inventory Report (IIR) on the German emissions of air pollutants (especially ammonia). The report documents the calculation methods used in the German agricultural inventory model GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2015 for the years 1990 - 2013. In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy plants. As required by the guidelines, emissions from activities preceding agriculture, from the use of energy and from land use change are reported elsewhere in the national inventories. The calculation methods are based in principle on international guidelines for emission reporting and have been continuingly improved during the past years. In particular, these improvements concern the calculation of energy requirements, feeding and the N balance of the most important animal categories. In addition, technical measures such as air scrubbing (mitigation of ammonia emissions) and digestion of animal manures (mitigation of emissions of methane and loughing gas) have been taken into account. Total emissions of methane (CH4) and laughing gas (N2O) from German agriculture (including the anaerobic digestion of energy plants) decreased from about 77.9 Tg CO2-eq in 1990 to about 64.2 Tg CO2-eq in 2013 (- 17.5 %). [...]Der vorliegende Berichtsband einschließlich des umfangreichen Datenanhangs dient als Begleitdokument zum National Inventory Report (NIR) über die deutschen Treibhausgas-Emissionen und zum Informative Inventory Report (IIR), über die deutschen Schadstoffemissionen (insbesondere Ammoniak). Er dokumentiert die im deutschen landwirtschaftlichem Inventarmodell GASEM integrierten Berechnungsverfahren sowie die Eingangsdaten, Emissionsergebnisse und Unsicherheiten der Berichterstattung 2015 für die Jahre 1990 bis 2013. Der Bereich Landwirtschaft umfasst dabei die Emissionen aus der Tierhaltung und der Nutzung landwirtschaftlicher Böden sowie aus der Vergärung von Energiepflanzen. Emissionen aus dem Vorleistungsbereich, aus der Nutzung von Energie sowie Landnutzungsänderungen werden den Regelwerken entsprechend an anderer Stelle in den nationalen Inventaren berichtet. Die Berechnungsverfahren beruhen in erster Linie auf internationalen Regelwerken zur Emissionsberichterstattung und wurden in den vergangenen Jahren beständig weiterentwickelt. Letzteres betrifft im Wesentlichen die Berechnung des Energiebedarfs, der Fütterung und der tierischen N-Bilanz bei den wichtigen Tierkategorien. Zusätzlich wurden technische Maßnahmen wie Abluftreinigung (Minderung von Ammoniakemissionen) und die Vergärung von Wirtschaftsdünger (Minderung von Methan- und Lachgasemissionen) berücksichtigt. Die Gesamtemissionen von Methan (CH4) und Lachgas (N2O) aus der deutschen Landwirtschaft (einschließlich der Vergärung von Energiepflanzen) sanken von rund 77,9 Tg CO2-eq im Jahr 1990 auf rund 64,2 Tg CO2-eq im Jahr 2013 (-17,5 %). [...