Organic agriculture boosts biodiversity on farmlands

Jun 26, 2014
Earthworm sampling on a grass verge between fields in Southern Bavaria. Credit: S. Wolfrum/TUM

Organic farming fosters biodiversity. At least that's the theory. In practice, however, the number of habitats on the land plays an important role alongside the type and intensity of farming practices. These are the findings of an international study that looked at 10 regions in Europe and two in Africa. The results has been published in Nature Communications. The study shows that even organic farms have to actively support biodiversity by, for example, conserving different habitats on their holdings.

An international team, including participants from Technische Universität München (TUM), investigated the contribution of organic farming to supporting between 2010 and 2013. Researchers wanted to explore whether organic farms are home to more species than their conventional neighbors. The team used uniform methods across Europe to capture data and analyze it to establish the impact of farming methods and intensity and of landscape features on biodiversity.

"Organic farming is beneficial to the richness of plant and bee species. However, observed benefits concentrate on arable fields," says TUM's Prof. Kurt-Jürgen Hülsbergen. His Chair for Organic Agriculture and Agronomy analyzed 16 Bavarian dairy farms.

The study investigated farms in twelve regions with different production systems. In each region, farms were selected randomly, half of them certified organic for at least five years. In Switzerland, grassland-based cattle farms were studied and in Austria the study looked at arable farms. In Italy and Spain, researchers focused on farms with permanent crops such as wine and olives, and on small-scale subsistence farms in Uganda.

More species because of field boundaries

More species were found in organic arable fields than in non-organic fields. In contrast, there was little difference in grasslands or vineyards. Organic farming benefited the four taxonomic groups of plants, earthworms, spiders and bees – which were sampled as surrogates for the multitude of creatures living on farmland – in different ways. In general, more species of plants and bees were found on organic than on non-organic fields, but not more species of spiders and earthworms.

If types of field boundaries such as grass verges or hedges were included in the comparison, the difference between organic and non-organic decreases. "Obviously, most species found in fields on organic farms tend to be concentrated in boundary areas on non-organic farms. There was little difference in the total number of species on the farms," explains Max Kainz, who headed the sub-project at TUM. The occurrence of rare or threatened species did not increase on organic farms, according to Kainz.

Even organic farms need to increase habitats

To sustain farmland biodiversity, which is currently under grave threat, researchers have identified complement organic farming methods with dedicated efforts to conserve habitats. To increase the number of habitats, the authors of the study recommend adding structural elements, such as woods, grass verges and fallow land, to farms. "Surprisingly, viewed across all regions, we did not find a higher number of natural habitats on organic farms than non-," reports Kainz.

"However, it was clear that habitat diversity is the key to diversity," adds Prof. Hülsbergen. He continues: "The results of the study underline the importance of maintaining and expanding natural landscape features – something that the EU's Greening Program has been trying to accomplish." If these additional habitats are different to the rest of the farm, for example hedges in grassland farms or herbaceous strips in arable , they have a huge impact on the biodiversity of a farm.

Explore further: Organic farms support more species

More information: Monika Wolf et al., 2014. Gains to species diversity in organically farmed fields are not propagated at the farm level, Nature Communications 5:4151 DOI: 10.1038/ncomms5151

add to favorites email to friend print save as pdf

Related Stories

Organic farms support more species

Feb 03, 2014

On average, organic farms support 34% more plant, insect and animal species than conventional farms, say Oxford University scientists.

Organic farming shows limited benefit to wildlife

May 05, 2010

Organic farms may be seen as wildlife friendly, but the benefits to birds, bees and butterflies don't compensate for the lower yields produced, according to new research from the University of Leeds.

Organic strawberries better pollinated

Mar 05, 2012

Organic cultivation methods not only benefit biodiversity; they also appear to have a positive effect on the ecosystem service pollination. In a study of strawberry plants in Skåne, the proportion of fully pollinated ...

Recommended for you

Giant anteaters kill two hunters in Brazil

10 hours ago

Giant anteaters in Brazil have killed two hunters in separate incidents, raising concerns about the animals' loss of habitat and the growing risk of dangerous encounters with people, researchers said.

Study indicates large raptors in Africa used for bushmeat

Jul 24, 2014

Bushmeat, the use of native animal species for food or commercial food sale, has been heavily documented to be a significant factor in the decline of many species of primates and other mammals. However, a new study indicates ...

Noise pollution impacts fish species differently

Jul 24, 2014

Acoustic disturbance has different effects on different species of fish, according to a new study from the Universities of Bristol and Exeter which tested fish anti-predator behaviour.

User comments : 0