Cost-effective support to organic farming to sustain biodiversity and ecosystem services
Organic farming is known to positively influence local biodiversity due to the absence of chemical pesticides and mineral fertilizers. However, the extent to which the conversion to organic farming could actually sustain biodiversity on the long term and at large spatial scales is still unknown. The main objective of the COST project is to find cost-effective allocations of organic farming in the landscapes to maximize biodiversity conservation and ecosystem services.
The overall aim of the COST project is to explore the cost-effectiveness of two agri-environment schemes (AES) in preserving biodiversity, that rely on two different strategies to conserve biodiversity in agricultural landscapes.
The first AES is organic farming, which bans the use of chemical pesticides and mineral fertilizers and thus can enhance biodiversity in the farmed area (land sharing: integration of biodiversity conservation objectives in the productive areas).
The other AES is the maintenance of semi-natural permanent grasslands, which create biodiversity-rich areas in the crop mosaic (land sparing: segregation of biodiversity conservation from the productive areas).
We will explore which strategy is the best for biodiversity conservation at the landscape scale and the type of species that benefit from such schemes (agricultural-bound species or rare endangered ones).
Another objective of this project is to explore the trade-offs between biodiversity conservation and agricultural production depending on the uptake of these two AES. For example, in case of synergy between biodiversity conservation and agricultural production (via a positive effect on wild organisms that provide yield-enhancing ecosystem services), taking land out of production (land sparing) or decreasing agricultural input (land sharing) might not necessarily decrease agricultural production in the landscapes due to a positive effect of biodiversity on crop yields.
Organic farming is promoted through agri-environment schemes (AES) because it produces public goods such as biodiversity conservation. It is desirable that these schemes are based on evidence and are cost-effective in achieving the objectives of management. A problem with evaluating its cost-efficiency is that biodiversity can be seen at different scales.
Today, evidence is weak to what extent organic farming benefit species conservation at large scales. Furthermore, support to organic farming has been questioned because resulting yield losses may compromise existing areas of high conservation concern, by forcing expansion of arable land at the expense of these conservation areas. However, effects of organic farming on biodiversity and crop production may vary strongly between landscapes and may even influence the efficiency of other schemes.
In this project, we evaluate the cost-effectiveness of current AES supporting organic farming and compare it with alternative allocations between schemes and landscapes. We use a design that allows us to account for relevant sources of uncertainty, including variation over landscapes and within are between seasons.
More specifically we will:
- Assess the marginal value of organic farming on biodiversity conservation in landscapes of varying complexity, which will be made by up-scaling estimates of butterfly diversity (used as a biodiversity indicator) to entire regions;
- Investigate the extent to which organic farming and semi-natural pastures counteract homogenization of biodiversity between farms by evaluating beta-diversity and nestedness of butterfly communities, in particular if species with different ecological traits are differentially affected;
- Measure mean and between-year stability of pollination of a flowering crop in relation to pollinator abundance and community composition, and how the relationship between pollinators and between-year pollination stability depend on the interactive effects of organic farming and preserving semi-natural pastures;
- Assess the cost-efficiency of the current uptake and spatial distribution of organic payments and support to grazing of semi-natural pastures in Scania relative to alternative allocations between AES and landscapes under budget or yield constraints.
Cong R, Ekroos J, Smith HG, Brady MV (2016). Optimizing intermediate ecosystem services in agriculture using rules based on landscape composition and configuration indices. Ecological Economics 128, 214–223.
Ekroos J, Ödman AM, Andersson GKS, Birkhofer K., Herbertsson L, Klatt BK, Olsson O, Olsson PA, Persson AS, Prentice HC, Rundlöf M, Smith HG (2016). Sparing land for biodiversity at multiple spatial scales. Frontiers in Ecology and Evolution 3, 145.
Ekroos J, Olsson O, Rundlöf M, Wätzold F, Smith HG (2014). Optimizing agri-environment schemes for biodiversity, ecosystem services or both? Biological Conservation 172: 65–71.
Formas – a Swedish research council for sustainable development