Agroforestry in Germany : from traditional to modern applications

Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.Agroforestry (AF) has a long history also in temperate climatic zones (e.g. grassland fruit orchards / "Streuobstwiesen" in southern Germany or wind brakes in northern Germany). However, due to the immense industrialization of the agricultural sector during the last decades those traditional land use systems were pushed to the fringes and were often not further promoted. On the other hand, modern agriculture also in most parts of Germany is progressively facing major ecological problems: i) loss of biodiversity, ii) soil erosion, and iii) eutrophication, including nitrate leaching. Furthermore, as all European member states should strive to a 20% share of renewable energy by 2020 (i.e., an equivalent of ca. 17.5 million ha of land dedicated to only produce energy crops), an additional pressure on farmland biodiversity as well as on soil and water resources can be expected. Within this context, information on most important and actual running AF activities in Germany, including contact addresses for further details are presented. All German_s AF activities were recently gathered in a newly formed AF working group (www.agroforst.org) to further promote AF on a national but also within the European AF association EURAF on the EU member state level (www.agroforestry.eu).Norbert P. Lamersdorf ; Soil Science of Temperate Ecosystems, Bu_sgen-Institute, University of G�ttingen, B�sgenweg 2, D-37077 G�ttingen, Germany

Bioenergie-Regionen stärken

Die Produktion und Bereitstellung holzbasierter Biomasse zur Energiegewinnung ist ein Baustein der Energiewende. Dabei spielen so unterschiedliche Herausforderungen wie Flächenverfügbarkeit, ökonomische Konkurrenzfähigkeit gegenüber anderen Landnutzungsformen bis hin zur öko logischen Verträglichkeit von Energieholz eine Rolle

Agroforestry creates carbon sinks whilst enhancing the environment in agricultural landscapes in Europe

Agroforestry, relative to conventional agriculture, contributes significantly to carbon sequestration, increases a range of regulating ecosystem services, and enhances biodiversity. Using a transdisciplinary approach, we combined scientific and technical knowledge to evaluate nine environmental pressures in terms of ecosystem services in European farmland and assessed the carbon storage potential of suitable agroforestry systems, proposed by regional experts. First, regions with potential environmental pressures were identified with respect to soil health (soil erosion by water and wind, low soil organic carbon), water quality (water pollution by nitrates, salinization by irrigation), areas affected by climate change (rising temperature), and by underprovision in biodiversity (pollination and pest control pressures, loss of soil biodiversity). The maps were overlaid to identify areas where several pressures accumulate. In total, 94.4% of farmlands suffer from at least one environmental pressure, pastures being less affected than arable lands. Regional hotspots were located in north-western France, Denmark, Central Spain, north and south-western Italy, Greece, and eastern Romania. The 10% of the area with the highest number of accumulated pressures were defined as Priority Areas, where the implementation of agroforestry could be particularly effective. In a second step, European agroforestry experts were asked to propose agroforestry practices suitable for the Priority Areas they were familiar with, and identified 64 different systems covering a wide range of practices. These ranged from hedgerows on field boundaries to fast growing coppices or scattered single tree systems. Third, for each proposed system, the carbon storage potential was assessed based on data from the literature and the results were scaled-up to the Priority Areas. As expected, given the wide range of agroforestry practices identified, the carbon sequestration potentials ranged between 0.09 and 7.29 t C ha−1 a−1. Implementing agroforestry on the Priority Areas could lead to a sequestration of 2.1 to 63.9 million t C a−1 (7.78 and 234.85

Growth and fructification of a Norway spruce (Picea abies L. Karst) forest ecosystem under changed nutrient and water input

In the mountainous region of a low mountain range (Solling mountains) an ecosystem manipulation experiment with roof constructions underneath the canopy of a 60-year old Norway spruce stand is run since 1991. The responses to artificially prepared, “pre-industrial" through fall and to extended summer droughts with intensive rewetting are investigated in two parallel roof experiments and evaluated against a roof control and an ambient control plot. After long terms of drought distinct reactions of the trees were visible in growth. The reactions of height-increment were more distinct than the effects on diameter-increment. Furthermore, the trees of the dominating social classes (Kraft I and II) reacted more on low water-supply than the dominated trees. So it is probable that a long lasting stress by drought effects changes the stand structure, too: the vertical structure of a stand would get more homogeneous and the diversity in the stand structure would decrease. Reduced input of sulphur and nitrogen did not show any distinct growth reactions within the 9-year observation period.Croissance et fructification d'un écosystème forestier d'épicéa commun soumis à un apport variable d'eau et de nutriments. Dans la partie haute d'une région montagneuse de moyenne altitude (Solling), on procède depuis 1991 à une expérience de manipulation d'un écosystème forestier à l'aide de constructions de toits en dessous des couronnes d'un peuplement d'épicéa commun âgé de 60 ans. Dans le cadre de deux expériences parallèles (de toit), on étudie les réactions à des précipitations “ préindustrielles " créées artificiellement et à une sécheresse estivale prolongée, suivie d'une réhumidification intensive, en évaluant et en comparant ces résultats à une placette témoin. Après de longues périodes de sécheresse, on a pu observer des réactions différentes des arbres sur le plan de la croissance. Les réactions au niveau de la croissance en hauteur s'avèrent différentes des effets sur l'accroissement en diamètre. En outre, les arbres dominants (Kraft I et II) témoignent d'une réaction plus prononcée à un faible apport d'eau que les arbres dominés. Ainsi, il est probable qu'un stress de longue durée par l'effet de la sécheresse modifie également la structure du peuplement : la structure verticale d'un peuplement devient alors plus homogène, tandis que la diversité du peuplement diminue. Les effets d'un apport réduit de soufre et d'azote n'ont pas révélé de réactions différentes sur le plan de la croissance au cours de la période d'observation de 9 ans