Suchergebnisse

Die Agrarpolitik des Bundes hat unter anderem zum Ziel, Agrarökosystemleistungen bereitzustellen, Umweltbelastungen zu reduzieren und die Resilienz der Landwirtschaft zu erhöhen. Die Kombination von Bäumen mit landwirtschaftlichen Unterkulturen, genannt Agroforst, kann dazu beitragen, diese Ziele zu erreichen, ohne die landwirtschaftliche Produktion wesentlich einzuschränken. Wir haben diejenigen Regionen identifiziert, in denen gemäss den Umweltzielen Landwirtschaft Umweltbelastungen auftreten, und in denen Agroforstsysteme einen Beitrag zur Minderung dieser Belastungen leisten können. Unsere Resultate basieren auf elf nationalen Defizitkarten der Umweltbereiche Biodiversität, Landschaft, Klima, Luft, Wasser und Boden. Demnach finden sich auf 13,3 % der landwirtschaftlichen Nutzfläche (LN) drei oder mehr Defizite gleichzeitig. Würden diese 13,3 % der LN zu Agroforstsystemen wie Baumreihen in Ackerkulturen, Futterbäumen und Schattenspendern für Tiere usw. umgewandelt, so könnten bis zu 13 % der Treibhausgasemissionen des Sektors Landwirtschaft kompensiert werden. Mit Hilfe der vorliegenden Karten und dem grossen Potenzial von Agroforstsystemen lassen sich in Zukunft Massnahmen entwickeln, die auf die lokalen Voraussetzungen und Umweltziele abgestimmt sind.

There is an increasing demand to study the long-term effects of land use from both local farm and wider societal and environmental perspectives. This study applied an approach to evaluate both the financial profitability of arable, agroforestry, and tree-only systems and the wider societal benefits over a period of 30-60 years. The biophysical inputs and yields from the three systems were modelled for three case study sites in the United Kingdom, Spain, and Switzerland, using a tree and crop simulation model called Yield-SAFE. A bio-economic model called Farm-SAFE was then used to compare the financial (EAVF) and economic (or societal) equivalent annual values (EAVE) by including monetary values for five environmental externalities: carbon dioxide emissions, carbon sequestration, soil erosion by water, and nitrogen and phosphorus balances. Across the three case studies, arable farming generated higher farm incomes than the agroforestry or tree-only systems, but the arable systems also created the greatest environmental costs. By comparison the agroforestry and tree-only systems generated lower CO2 emissions and sequestered more carbon. Applying monetary values to the environmental externalities meant that the EAVE of the agroforestry and tree-only systems were greater or similar to that for the arable system in the UK case study. In Spain, the slow predicted growth of the trees meant that, even after including the environmental externalities, the arable system created greater societal benefit than the agroforestry and tree-only systems. In Switzerland, including the environmental externalities increased the attraction of the tree-only system, but the high subsidies for arable and agroforestry systems meant that the EAVE for the agroforestry and arable systems were the most attractive from a farmer's perspective. A breakeven analysis was used to determine the environmental externality values at which the agroforestry and tree-only systems produced the same societal return as the arable system in each case study. In the UK, a carbon price of ₠16 (t CO2)-1 allowed the EAVE of the agroforestry system to attain parity with the arable EAVE. In both the UK and Spain, an environmental nitrogen cost of ₠3-6 (kg N)-1 was sufficient for the EAVE of the agroforestry and tree-only systems to match those of arable farming. Because trees on farms provide ''economies of multifunction'' for environmental benefits, the breakeven values will be less if environmental benefits are considered together as packages. The described approach provides a method for governments and others to examine the cost effectiveness of new agri-environment measures

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 million t CO2eq a−1) depending on the type of agroforestry. This corresponds to between 1.4 and 43.4% of European agricultural greenhouse gas (GHG) emissions. Moreover, promoting agroforestry in the Priority Areas would contribute to mitigate the environmental pressures identified there. We conclude that the strategic and spatially targeted establishment of agroforestry systems could provide an effective means of meeting EU policy objectives on GHG emissions whilst providing a range of other important benefits. ; peerReviewed