Biodiversity as a measure of differences between organic and conventional farming: a case study.

Natural ecosystems are a structural and functional association of biotic-abiotic components within a physic-chemical environment. Such a dynamic aspect gives natural surfaces the ability to maintain high qualitative properties of constitutive resources (water, air, soil), of land (landscape) and of habitat (for animal and vegetal species). These properties are fundamental to the concept of sustainability (Lewandowski et al., 1999) and biodiversity is a way to estimate them in a farm context (Bockstaller and Girardin, 1997) and for a comparative use (Caporali et al., 2003). Biodiversity indicators are largely used for detecting and evaluate the amount and effectiveness of natural surfaces within a farm (Hole et al., 2005). In the following study indicators at plot scale and farm scale were used to compare the effects of organic and conventional management on occurrence of spontaneous vegetation.