Although promotion of biodiversity begins with soil reactivation (90% of all animal species live in the soil, and in one gram of healthy soil up to one billion micro-organisms and up to 60,000 different species can live), soil life is however not completely detached from the biodiversity visible above ground.
Plants constitute the link between habitats underground and above ground. In order for them to be able to effectively exercise this linkage function in the long term, they enter into a wide range of partnerships with their natural surroundings not just in the dark realms of their roots but also above ground. Just as they need the help of the wind or insects for pollination, they also need partnerships with beneficial organisms to fight their natural enemies.
The greater the plant diversity is, the greater the variety of insects, birds, reptiles, etc. living in self-regulating competition. Where plant diversity is destroyed by monocultures, a negative selection of bacteria, fungi, insects, etc. will occur, with only those species able to feed on the remaining plants in a position to retain their natural habitat. As their natural enemies are unable to develop on account of the one-sided focus of the crop, the few remaining species adapted to the monoculture are able to multiply unhindered, developing into pests and becoming a plague. Pesticide and insecticide spraying provides only short-term relief, as this encourages the negative selection, meaning that new pesticides and insecticides in increasingly high dosages need to be applied.
A high level of vineyard biodiversity is not just a way of controlling pests through the promotion of their natural enemies, but also helps strengthen a vine’s own immune system. In addition to stipulating a cover crop with abundant diversity between the vines, the Charter for Vineyards with High Biodiversity sets forth the following supplementary measures:
- Planting shrubs at the ends of each row, in places where they do not interfere with work. Criteria for the selection of shrubs include their attraction for butterflies and other insects, the provision of nesting opportunities, root symbiosis, and the use of any fruit. Native species are to be preferred.
- Interspersing hedges with the vines. Dependent on local circumstances, there should be at least 2 20-metre hedges per hectare. Hedges constitute biological hotspots, acting as corridors linking up ecological areas. Moreover they constitute a natural barrier preventing the spread of harmful fungi.
- Planting fruit trees as a way of improving vertical diversity. The presence of trees in the middle of a low-growing and little-structured field/vineyard is a great way of attracting birds, insects and other groups of animals. They are also a way of promoting the long-term colonisation of an ecosystem. At least one tree per hectare should be planted amidst the vines, and no point of the vineyard should be further than 50 metres away from a tree.
- The provision of compensatory areas (at least 50 m2 per hectare) as diversity hotspots both within and on the perimeter of a vineyard. These areas become the home of aromatic herbs and wild flowers.
- The provision of structural elements, such as piles of stones or wood. These provide a habitat for reptiles and insects. The provision of nesting aids for bees, insects and birds. These can be integrated into trellis posts. Perches for birds of prey, with the latter helping to keep the rodent population in check.
- Instead of grubbing up old vineyards and completely replanting them, vines that have become too old are replaced individually. The young vines are taken from the vineyard using massale selection and grafted onto existing root structures on-site. In doing so, selection perfectly adapted to the terroir takes place over generations. The thus achieved genetic diversity reduces the likelihood of infections through pests, boosts wine quality and also improves vine resilience to prevailing conditions.
The intelligent use of resources and material cycles in wine-growing and agriculture can make a decisive contribution to protecting the environment, the climate and biodiversity, without negatively influencing productivity. The most visible sign (even for non-experts) of an incipient restoration of harmony in the vineyard is the number of different types of butterflies. Whereas five years previously (before conversion to the above-discussed methods) only two types of butterflies were to be found on the Delinat Institute’s vineyards, 2010 saw some 60 different types being counted. The following arguments are however probably of greater importance to wine-growers:
- The disease resistance of the vines has greatly improved over the last five years, with the consequence that neither chemical pesticides nor sulphur are needed any longer.
- Although fertilisers and herbicides are no longer applied, vine vitality and yields have stabilised at a high level.
- With sulphites and other oenological supplements no longer being used, the ageing potential of the wines has increased significantly.
- The increased labour costs are compensated by the savings in fertilisers and pesticides (costs for pesticides and fertilisers: EUR 150 / ha).
- The motivation of the people working in a bio-diversified vineyard is much higher, as shown by their increased efficiency and their willingness to take over responsibility.
- The aesthetic and ecological quality of the vineyard can be used as an important marketing argument vis-à-vis customers.
And last but not least, wine-growers will find themselves rediscovering pride in their work, creating great terroir wines in partnership with nature.
Stay tuned for Part three where we will share the charter for biodiversity in vineyards.
Missed the first part of the series? Head back to read it here.