Project

VineDivers include traditional wine producing EU countries along a west-eastern transect through Europe: Spain, France, Austria and Romania. In total, vineyards cover 3.277 Mio ha of the total arable area in Europe. Even if the wine growing area has been declining for the past few years due to the changing market situation and the implementation of the new Common Market Organization (CMO), the EU-27 is the world leading wine producer and exporter (France and Spain occupy fourth and fifth place in worldwide production of grapes). Compared with other wine growing areas, EU vineyards are smaller affording more labour-intensive management. However, this economic disadvantage may be a benefit for supporting biodiversity and associated ecosystem services in viticultural landscapes. Worldwide, vineyards are often intensively managed monocultures of Vitis vinifera with, especially in dry areas like in Australia and Asia, bare soil or inter-row vegetation consisting of only one grass species (e.g. rye grass). These systems primarily aim at optimizing wine quality and quantity but commonly ignore additional ecosystem services these agroecosystems might additionally provide.

Vineyards may establish and maintain a high degree of biodiversity and include rather complex ecosystems, especially if they are situated at steep slopes with small-scale terraces. Within this agroecosystem, the land sharing vs. land sparing debate is in principle less of an issue, as areas between vine rows could inhabit a diverse flora consisting of local species or cover crops Traditionally, also landscape elements like solitary trees, hedges or stone walls are important elements of diverse temperate viticultural agroecosystems. These elements provide important ecosystem services like erosion mitigation, the provision of habitat and food sources for natural enemies and a diversity of crops. In addition, biologically and structurally diverse viticultural landscapes provide a high aesthetic value for recreation and tourism (i.e. cultural ecosystem services). However, these multifunctional viticulture agroecosystems are declining, due to more intensified and increasingly mechanised management. Current agri-environmental regulations may additionally promote the eradication of structures that favour biodiversity such as trees or stone walls within vineyards since these areas reduce the eligible area for subsidies.

Traditional vineyard management was characterised by frequent tilling in order to eradicate all spontaneous plants (“weeds”) and to reduce water and nutrient competition between vines and “weeds”. Later on, herbicides were frequently used for removing these “weeds”. These management measures are nowadays associated with ecosystem disservices as very high rates of erosion, degradation of soil structure and fertility, contamination of groundwater and high levels of agricultural inputs like pesticides. These and other management measures (e.g. application of copper fungicides) have also been shown to negatively affect earthworms, important ecosystems engineers and the largest component of the soil faunal biomass.

Cover crops in vineyards provide a large range of different ecosystem services such as improving soil water retention, soil organic carbon, soil biological activity, nutrient cycling, mitigation of soil erosion, weed and pest suppression, enhancing biological control and biodiversity conservation. Despite of a higher competition for water with the vines especially in dry climates, cover crops have been shown to improve wine quality. Most studies examine the role of cover crops on very few ecosystem services like the benefits for biological control, pest mitigation or the positive impact on soil fertility, soil organic matter content, improved microbiological activity and N availability. Despite of the large range of positive effects of cover crops and/or spontaneous vegetation in vineyards, the strong competition for water with the vines and the associated reduction of grape yields up to 40% limits their adoption in rainfed vineyards in semiarid or sub-humid climates. Therefore trade-offs exist between soil conservation, biodiversity conservation and production depending on climatic and pedological conditions. Consequently, optimum management practices have to be sought for different regions.

We are currently still missing detailed studies on the effects of species-rich inter-row vegetation on a variety of ecosystem services in various viticultural landscapes. Even if cover crops are increasingly becoming the state of the art in vineyard management in areas with summer rain or irrigation, common seed mixtures of legumes and/or grasses might suppress the former typical vineyard bulb geophytes and therophytic species. A Swiss study found a significant increase of beneficial arthropods with increasing plant species richness and especially with higher numbers of flowering dicotyledonous species in vineyards. Plant biodiversity therefore not only provides essential supporting and regulating ecosystem services like the conservation of soil structure and fertility, nutrient cycling and clean water provision as well as the provision of food source and habitat for beneficial arthropods and pollinators.

Bees play an important role in arable ecosystems as they provide pollination services for wild plants and crops. About 87% of all crop species depend or benefit at least to some extent upon animal pollination. Grape vines are commonly regarded as being wind or self-pollinated. Nevertheless, there are reports from particular cultivars (e.g., cv. “Cardinal”) which benefit from bee pollination and some related vine species like Vitis rotundifolia which are used for crossings entirely depend on insect cross-pollination. There is clear evidence of recent declines in wild bees as well as in honey bees which can furthermore lead to a loss of plant species diversity. Potential drivers of pollinator decline are: habitat loss and fragmentation, agrochemicals, pathogens, parasites, climate change and interactions between them. Bees are especially affected by local farm management (e.g. use of pesticides, diversity of flowering plant species) and the surrounding landscape structure which provides nesting and floral resources within foraging distance. Pollinator habitat enhancement has been shown to deliver a range of secondary benefits to agriculture and the surrounding landscape by enhancing overall biodiversity and providing a range of ecosystem services.

Our project aims at analysing the implications of different management regimes (high intensity tilling regimes vs. „green” vineyards with cover crops or wild plants) in vineyards on above- and below ground biodiversity and the associated ecosystem services. To the best of our knowledge, no study simultaneously examined the impact of vineyard management on plant diversity, soil biota and pollinators, and the consequences for a variety of ecosystem services. Our present knowledge on the interactions between the different trophic levels and associated ecosystem services is still very poor and therefore it is impossible to predict how these interlinkages will be altered by changed land use and climate change. Soil management will be especially challenged under predicted decrease in soil moisture content due to climate change.