Growth of silicalite-1 films on gold substrates

International audienc

Deposition of continuous silicalite-1 films on inorganic fibers

International audienc

Micro-scale heterogeneity of spiders (Arachnida: Araneae) in the Soutpansberg, South Africa: A comparative survey and inventory in representative habitats

Coarse-scale studies that focus on species distributions and richness neglect heterogeneity that may be present at finer scales. Studies of arthropod assemblage structure at fine (1 × 1 km) scales are rare, but important, because these are the spatial levels at which real world applications are viable. Here we investigate  fine-scale variation in spider assemblages, comparing five representative  vegetation types in the western Soutpansberg, Limpopo Province, South Africa. We assess these vegetation types in terms of their family and species composition, as well as levels of endemicity, relating these differences with vegetation  structure.We inventoried 297 species (49 families) in an area less than 450 ha, as part of South African National Survey of Arachnida. Analysis of the results suggests that endemic taxa are associated with Tall Forest and, to a lesser extent,Woodland. TheWoodland had the highest species diversity, and much of the variation observed in spider assemblage structure is explained by these two vegetation types. Based on   vegetation structure variables that explained significant variation in spider   assemblages, human influence through bush encroachment will result  in a change of spider assemblages to that of Short Forest and Mosaic Woodland vegetation types, with implications for biodiversity maintenance and heterogeneity.Key words: endemicity, South Africa, spider, SANSA, conservation, Soutpansberg

The synthesis of discrete colloidal crystals of zeolite Beta and their application in the preparation of thin microporous films

International audienc

Assessing local scale impacts of Opuntia stricta (Cactaceae) invasion on beetle and spider diversity in Kruger National Park, South Africa

There is a paucity of studies examining direct impacts of introduced alien species on biodiversity, a key need for motivating for alien species control in conservation areas. The introduced prickly pear (Opuntia stricta) has invaded some 35 000 ha of Kruger National Park. We investigated the effect of O. stricta on beetle and spider species assemblages in the Skukuza region of Kruger National Park. We used unbaited pitfall traps over a 12-month period in four treatments of varying O. stricta density. Species richness, species density and abundance of beetles and spiders were compared. A total of 72 beetle and 128 spider species were collected. Species richness and species density for beetles and spiders did not differ significantly  across the four treatments. Assemblages for spiders did not differ across  treatments but beetle assemblages were significantly different from uninvaded control sites. This study suggests that the current density of O. stricta does not significantly affect spider species richness, density or assemblages but that beetle assemblages are significantly affected.Key words: Araneae, arthropods, Coleoptera, invasion impacts, invasive plants,  non-native, Opuntia stricta