A bioindicator protocol forsustainable agribusiness in South Africa,using new crops as case studies

[摘要] English: This study is innovative in that it proposes an Index determined by the functional qualities of arthropods and relates a monetary value to these qualities, based on new crop case studies conducted at two contrasting agroecosystem sites in South Africa. The sustainability of an agribusiness depends on the conservation of its biodiversity. The development of a robust methodology that can be used in an Environmental Management System (EMS) is thus necessary by (i) implementing measures of arthropod and general vegetation biodiversity and (ii) incorporating a monetary value to functional diversity, as mechanisms to indicate the degree of disturbance within the agro-ecosystem.The main objectives were to determine the relationship between arthropod diversity indices (species richness, abundance and evenness) and arthropod assemblages; to determine the relationship between the edge effect reaction of arthropods and the resistance and resilience of an agroecosystem; to determine the relationship between agricultural practices (such as pesticides and fertilizers), surrounding vegetation and arthropod richness and abundance; and to determine the relationship between arthropod species richness and abundance, and the proposed AFI (Agroecosystem Function Index), which is based upon the economic value of ecosystem services. Case studies were conducted to pinpoint potential indices of an ecological nature, with specific reference to the diversity indices of arthropods, as part of the methodology. Arthropods were used as an indicator community since they are prevalent, have high species diversity, are easy to sample, are important in ecosystem function, provide early detection of ecological changes and respond to environmental changes faster than vertebrates. The influence of agricultural management practices on this diversity is also taken into consideration. Quantitative and qualitative analysis revealed distinct patterns within the biodiversity at all the locations, relative to the frequency and diversity of vegetation sampled. Thus aspects of ecology (edge-effect, guild structure and functional diversity) should indicate a relationship between communities, which in turn would indicate the level of ecosystem integrity.The level of ecological integrity could be taken into consideration when adopting a quality Environmental Management System (EMS). Possibilities of incorporating a monetary value model, such as the Agroecosystem Function Index (AFI), to biodiversity analysis, that in turn has a bearing on ecosystem services and agribusiness, is also addressed. An EMS bio-indicator protocol is important as an aid to reduce the impact of agricultural management practices on the agro-ecosystem and to increase its functional efficiency.

[发布机构] University of the Free State