The found strong distance decay of community similarity indicates spatially highly heterogeneous diatom communities mainly driven by temporally varying conductivity gradient at the marine-freshwater transition zone.Д«otswana constitutes a major gap in our knowledge of the distribution of Ostracoda in the region of Southern Africa, restraining thorough biogeographic interpretations. Metacommunity organization in the studied rock pools was probably largely explained by a combination of species sorting and mass effect given the small spatial study scale. The relative influence of environmental factors increased with time, accounting for the largest share of the variation in species composition and distance decay of similarity in July. Community similarity was related to both environmental and spatial distance between the pools even when the other variable group was controlled for. The community composition was explained by both environmental and spatial variables (especially conductivity and distance from the sea) in each month the joint effect of these factors was consistently larger than the pure effects of either variable group.

The studied communities housed a mixture of freshwater, brackish, and marine species, with a decreasing share of salinity tolerant species along both temporal and spatial gradients. We used a combination of direct ordination, variation partition, and Mantel tests to investigate the metacommunity patterns. We examined temporal variation in the relative roles of environmental and spatial factors for diatom community composition among brackish-watered rock pools on the Baltic Sea coast over a 3-month period. However, only little is known about temporal variation in metacommunities and their underlying drivers.

The best sampling strategy to assess species richness in these rock pool systems is to randomly sample three to four pools in a cluster, each in the final phase of their hydrocycle.Дifferent metacommunity perspectives have been developed to describe the relationship between environmental and spatial factors and their relative roles for local communities. All new taxa were permanent inhabitants, illustrating the need for more intense and time-integrated studies of these ephemeral systems and especially the permanent residents with specific adaptations to the vagaries of their variable habitat. A new chydorid species, four new turbellarian taxa and two new ostracod species were discovered.

Rock pool species were separated in permanent and ephemeral inhabitants, based on their strategy to survive or escape the frequent dry phases of their habitat, respectively. A faunal list is presented and described. By means of frequent sampling (every other day) during an entire wet phase (hydrocycle), we attempted to get a time integrated overview of invertebrate species composition in a set of 18 rock pools from two clusters (meta-communities). To date, studies on these systems have focused mainly on individual species or particular interactions. In semi-arid Botswana, such habitats occur mainly on the granite outcrops in the southwestern Hardveld zone. Rock pools on granite outcrops occur worldwide and are poorly studied, despite their intrinsic biological interest.

Ephemeral rocky outcrop