See my previous post on biodiversity in the vineyards for definitions of terms, some background and details of a specific project in the Loire.
There are two strands to the arguments about why biodiversity is important and why we should preserve it. The first are the economic aspects such as its potential to improve the production of agricultural commodities; its role in the regulation of soil fertility and the physical and chemical cycles of the Earth; and the possibilities for the tourist industry. The second is ethical and cultural - our moral duty to future generations and the need to maintain the potential of living organisms.
Viticulture is an intensive monoculture resulting in a homogeneous landscape with low levels of biodiversity. If we want to challenge this approach to winemaking the attack must be two pronged. Chemical inputs and landscape homogeneity must be tackled simultaneously.
A landscape scale approach allows the monitoring of both changes in the landscape such as the creation of hedges and crop margins to shelter predators, and the changes in the pest population. The main insect pests in the vineyards are leafhoppers, who suck leaves dry and spread diseases, and moths, who's caterpillars eat the grape flowers and the forming fruit.
Source: Protection des Paysages Viticoles, a paper by G. Pain et al, 2010, Mission Val de Loire.