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De geo-constitutionele rechtsstaat: een hervormingsagenda In deze bijdrage gaat de auteur in op de constitutionele vraag over de verhouding tussen de mens en de natuur. [ABSTRACT FROM AUTHOR]

The influence of organic and conventional soil management practises on the density, diversity and activity of the soil dwelling mesofauna in vineyard soil were investigated over several seasons in this quantitative field study. Soil samples were taken over several seasons in organically and conventionally managed plots as well as in a natural control plot and organisms were extracted to count and identify the soil mesofauna (mostly Collembola and Acari). The feeding activity of the mesofauna in the soil was measured with the bait lamina method and buried litter bags to measure the decomposition of organic material over time. No statistically significant differences in numbers, diversity and activity of the mesofauna were found between the organically and conventionally managed plots. Therefore our stated hypothesis that the conventional practice, as employed here, would be detrimental compared to the organic treatment, could not be accepted. The activity of the mesofauna was significantly higher in the two managed plots than in the natural, untreated control plot from which we deduce that conditions in the two managed plots were favourable for the mesofauna. [ABSTRACT FROM AUTHOR]

A general overview of the macro-invertebrate diversity in the Marico River, North-West Province, South Africa: The Marico River, in the North West Province of South Africa, has been declared a priority area in terms of conservation. The purpose of this investigation was to determine, document and publish the macro-invertebrate diversity of this river. Macro-invertebrates were collected during five surveys at six sites in the Marico River by means of appropriate nets and techniques, while selected water quality parameters were measured in situ. A total diversity of 172 taxa (20 orders and 81 families), represented by 12540 organisms, was found during this investigation. Most of the families which are known to display a preference for high water quality have been found. Values for temperature, pH, EC, flow rate and turbidity were within the tolerance ranges for aquatic macro-invertebrates throughout the study. From the results it can be concluded that the river has predominantly high taxa richness and diversity and that the taxa are evenly distributed, which indicates a healthy ecosystem. The presence of several highly sensitive taxa further supports this statement. [ABSTRACT FROM AUTHOR]