Action: Maintain traditional orchards
- Two replicated site comparisons from Germany and Switzerland found that, on average, 12% of traditional orchards in Swiss Ecological Compensation Areas were of ‘good ecological quality’, and traditional orchards under a German agri-environment scheme did not have more plant species than paired control sites. Traditional orchards in Ecological Compensation Areas appeared to offer little benefit to birds.
- A replicated, controlled site comparison study in Germany found that plant species richness was higher on mown orchards than grazed or abandoned ones, but numbers of species and brood cells of bees and wasps did not differ.
Traditionally-managed orchards are low-intensity systems that have the potential to provide unique habitats for wildlife and that tend to hold older and rarer varieties of fruit. However, they are threatened in many countries, with 60% of traditional orchards in Britain having been lost and another 30% converted to intensive production since the 1950s.
Supporting evidence from individual studies
A replicated, controlled site comparison study in 1998 and 1999 of 45 orchard meadows in Lower Saxony, Germany (Steffan-Dewenter & Leschke 2003) found that plant species richness was higher on mown meadows than grazed or abandoned meadows, but that numbers of species and brood cells of bees and wasps (Hymenoptera) did not differ. A significantly higher number of plant species was found on mown (24) than abandoned meadows (18), grazed meadows had intermediate numbers (22). A similar trend was found for grasses (8 species vs 5), but not herbs (16 vs 12). Plant height was higher on abandoned meadows (100 cm), than mown meadows (85 cm) and grazed meadows (55 cm). Vegetation cover did not differ significantly between management regimes. The number of species or brood cells for all species, or separately for bees (Apidae), potter wasps (Eumenidae) or sphecid wasps (Sphecidae) did not differ between treatments. However, the abundance of sphecid wasps was significantly higher on abandoned meadows (180 brood cells) than grazed (55) or mown (60) meadows. There was no significant difference in species richness of natural enemies or the rate of parasitism of bees and wasps between management types. Orchards were either mown once or twice a year, grazed (usually by sheep) or had no management for at least five years. Vegetation was sampled on a central plot of 25 m within each site from June-July 1998. Nesting traps (4/location) were set up at regular distances at each site from April-September, 1998 and 1999.
A replicated site comparison between 1998 and 2001 (Herzog et al. 2005) found that, on average, only 12% of traditional orchards in Ecological Compensation Areas on the Swiss plateau were of ‘good ecological quality’ (based on national guidelines for Ecological Compensation Area target vegetation). Orchard Ecological Compensation Areas appeared to offer little benefit to orchard birds, with territories of only one species (green woodpecker Picus viridis) found more frequently in or near Ecological Compensation Area orchards (11 territories) than expected. Plant species and orchard characteristics were recorded for 187 Ecological Compensation Area orchards (total area 108 ha) between 1998 and 2001. Territories of breeding birds were mapped in 23 study areas, based on three visits between mid-April and mid-June.
A replicated paired site comparison in Bavaria, Germany (Mayer et al. 2008) found that traditional orchards managed under the Bavarian agri-environment scheme ‘Agricultural Landscape Programme’ (KULAP) did not have more plant species than paired control sites. There were 26 site pairs, and around 18-20 plant species/site. Pairs of 25 m2 grassland plots were selected from 4,400 plots in the Bavarian grassland survey. All plant species within the plot were recorded between April and October (year not given). Plot pairs were in the same natural landscape, 90% within 10 km of each other. In each pair, one plot was under an agri-environment scheme agreement, the other was not - in this case traditional orchard management.
- Steffan-Dewenter I. & Leschke K. (2003) Effects of habitat management on vegetation and above-ground nesting bees and wasps of orchard meadows in Central Europe. Biodiversity and Conservation, 12, 1953-1968
- Herzog F., Dreier S. & Hofer G. (2005) Effect of ecological compensation areas on floristic and breeding bird diversity in Swiss agricultural landscapes. Agriculture, Ecosystems & Environment, 108, 189-204
- Mayer F., Heinz S. & Kuhn G. (2008) Effects of agri-environment schemes on plant diversity in Bavarian grasslands. Community Ecology, 9, 229-236