Expression of on-farm functional biodiversity as affected by management and multi-scale agroecosystem disturbance

The relationship between biodiversity and ecosystem functioning has emerged as one of the most controversial research areas over the last decade. Agroecosystems are per definition subjected to disturbances. The intensity and frequency of management practices representing the main disturbance in agroecosystems, affect its biodiversity. The part of the biodiversity that provides a certain ecosystem service, can be called a functional groups. Thus, management likely affects the stability and functioning of the agroecosystem through its impact on the functional biodiversity. This paper presents the first part of a project which aims to contribute to the understanding of 1) how on-farm disturbance by management affects on-farm functional biodiversity and 2) how composition, structure and disturbance at various spatial scales modify thi interaction. The first aspects that had to be determined were: 1) How to express disturbance in such a way that it can be compared at different spatial scales and in different agroecosystems? 2) What are the agroecosystem objectives and problems? 3) Thus, what is the functional biodiversity in the different cropping systems? 4) What measures are needed to indicate the level of functionality of the functional groups? 1) vegetation and land use type were identified as the main indicator for disturbance level at all spatial scales. 2 and 3) Agroecosystem disturbance is mainly caused by the cropping system, with disturbance levels decreasing from annual crops to perennial tres. Two extreme cropping systems (olive groves and annual crop rotation) were chosen, each with a low and a high crop management intensity. 4) Measures are indicated in a methodological table.