Kathrin Trommler, Project Coordinator with the Ecosystem Services Research Group, Berlin-Brandenburg Academy of Sciences and Humanities, provides a look into one European agricultural landscape with deep historical roots. Representing a slightly different type of agrobiodiversity than the field crops usually discussed, this diversity of fruit trees characterizes the landscape, holds cultural significance, and contributes to the preservation of environmental services.
In European landscapes, people and nature have co-evolved over centuries. How these cultural landscapes look is the result of persistent landscape change as a result of a highly diverse set of land uses. One typical traditional landscape stretches like a belt through Western, Central, and Eastern Europe: scattered fruit tree meadows. This agroforestry system is a historical form of commercial orcharding which is composed of open stands of standard fruit trees, undersown with crops or managed grasslands. In south-west Germany,one of the largest contiguous landscapes of this type in Europe is found in the Swabian Alb (Schwäbische Alb).
Scattered fruit trees (German: Streuobst) are defined as “tall trees of different types and varieties of fruit, belonging to different age groups, which are dispersed on cropland, meadows and pastures in a rather irregular pattern” (Herzog, 1998). The most common species are apple, pear, plum, sweet cherry, and walnut. Planted at an average density of 20-100 stems per hectare, the minimum stem height of 160 cm allows for fodder grasses, cereals, root crops, or vegetables to grow below the trees. Typical scattered fruit tree arrangements encompass whole valley slopes or greenbelts around villages, but also occur at the scale of alleys along streets and individual trees or tree groups. Nearly 6,000 hectares of grassland and 600,000 scattered fruit trees are found in the foothills of the Swabian Alb Mountain Ranges, part of a UNESCO Biosphere Reserve.
Scattered fruit tree meadows are low-intensity systems that need to be maintained through regular, but extensive and moderately frequent human uses. The grass understory is mown once or twice a year, if not grazed extensively by sheep or other livestock. They are primarily in small-scale private ownership. The largest amount of the fruit is processed for juice, especially apple juice. Further products are dessert fruit, liquors, must, or vinegar. Along with the fruits the agro-forestry system allows the production of hay and fruit as animal feeds, firewood, or timber.
Although cultivated for economic reasons in previous days, today scattered fruit trees are appreciated and enhanced mostly due to their biodiversity and ecosystem services. The habitats’ combination of trees and low-intensity understory layers results in small-scale and highly diverse structures and ecological gradients (site conditions, microstructures, ecological niches). The genetic diversity and local varieties are very high, with more than 3,000 fruit varieties found in Germany in 2008. Traditional orchards host five times more bird species than modern, mechanized fruit tree systems, whose horizontal and vertical vegetation structure are of a completely different shape. In addition, scattered fruit tree meadows provide critical regulation services by improving the local climate, buffering groundwater pollution, or controlling surface-runoff and soil erosion. Also the cultural services provided by the orchards are manifold. The recreational service contributes considerably to local well-being and attracts day tourists.
Due to the variety of valuable ecosystem services perceived by the inhabitants, the decline of scattered fruit trees over the last decades has provoked deep concerns. Both outright destruction and abandonment of land have caused the losses. On the one hand, green belts around villages suffer from increasing urbanisation. On the other hand, many orchards have been abandoned as a result of a lack of profitability and have been converted into forests. Many remaining fruit trees are overaged, lack regeneration, and suffer from neglect.
A number of different policy measures for preservation, maintenance, and revitalizing of orchards have been developed in past years. For example, a European Union co-financed scheme aims at protecting birds in scattered fruit tree habitats and maintaining the habitats at the same time by promoting bird-friendly cutting of trees and revitalising trees on communal land. Other supporting schemes entail the processing and marketing of fruits, given that the profitability of this land-use type is an important factor in the farmers’ perspective. Activities for conserving scattered fruit trees are a successful example of combined top-down and bottom-up approaches. But so far, they have not reached the scale necessary to ensure the long-term persistence of this valuable landscape.
Suggested further reading
Herzog, F. 1998. Streuobst: a traditional agroforestry system as a model for agroforestry development in temperate Europe. Agroforestry Systems 42: 61-80.
Kizos, T., Plieninger, T., Schaich, H. & Petit, C. 2012. HNV permanent crops: Olives, oaks, vines and fruit trees. In: Oppermann, R., Beaufoy, G. & Jones, G. (eds.). High Nature Value Farming in Europe – 35 European Countries, Experiences and Perspectives. Ubstadt-Weiher: Verlag Regionalkultur, p. 70-84.