The effect of different vineyard management systems on the epigaeic arthropod assemblages in the Cape Floristic Region, South Africa

[摘要] In the Cape Floristic Region of South Africa, where wine grape production andbiodiversity conservation are of major importance, innovative management of thelandscape is necessary to integrate the two activities. Alternative farming, such as organicand biodynamic farming, focuses on the preservation of biological processes inagroecosystems with the aim of increasing the sustainability of these sytems. It has beendemonstrated in other regions that alternative farming can enhance biodiversity. Thisstudy assessed the potential of alternative vineyard management to conserve biodiversity,in particular epigaeic arthropod diversity, relative to the more widespread integratedvineyard management in the CFR. A hierarchical design was used, consisting of threelocalities, with three land-uses nested within each locality. The land-uses were alternativevineyards, integrated vineyards and natural vegetation sites as reference habitats.Sampling was done in June and October 2006 using pitfall traps. Nested ANOVAs wereused to test for differences in abundance and species richness of the total assemblages,functional feeding guilds and selected generalized predatory taxa. Assemblage patternswere assessed using hierarchical agglomerative clustering and non-metricmultidimensional scaling. Canonical correspondence analyses were used to evaluate theeffects of environmental variables, management practices and landscape variables oncommunity composition. Alternative vineyards supported a significantly higher overallarthropod abundance and species richness, more diverse predatory, saprophagous,phytophagous and omnivorous guilds, as well as more abundant and speciose spider androve beetle assemblages than the integrated vineyards. Integrated vineyards harboured agreater abundance of predators, whereas results for nectarivores, wood borers, parasitoidsand carabid beetles were variable. The differences could be explained in part by highernon-crop vegetation complexity and reduced management intensity of the alternativevineyards. Community composition was influenced by a combination of managementpractices, the surrounding landscape and geographic locality, which highlighted theinterdependence of the cultivated land and its surroundings.

[发布机构] Stellenbosch University