Effects of debris piles and pools along dry riverbeds on nutrients, microbial activity, and ground-dwelling arthropods: A Namibian ephemeral river case

Publication Year:

Debris piles and dry pools are common landscape elements along ephemeral river channels. However, their effects on resource availability and arthropod species diversity have been neglected so far. We investigated whether debris piles and pools along dry riverbeds generate nodes of environmental resources, influence microbial activity, and provide key habitats for ground-dwelling arthropods. We studied three different habitats (channel, debris pile and dry pool) to analyze organic matter, nutrients and microbial activity in dry sediments, and included two further habitats (riparian and upland areas) for ground-dwelling arthropod assemblages along a major ephemeral river (Ugab River, NW Namibia). We observed higher concentrations of organic matter and macro- and micro-nutrients in debris piles than in pools, and higher concentrations in both landscape elements than in the sandy channel matrix. Microbial activity showed a positive relationship with organic matter and nutrient availability in sediments. Debris piles, dry pools and channels harbored diverse and abundant ground-dwelling arthropod assemblages similar to adjacent terrestrial areas. Debris piles and pools differed in assemblage composition not only from riparian and upland areas but also from the sandy channel matrix. Overall, debris piles and dry pools acted as nodes of soil fertility, enhanced microbial activity, and shaped ground-dwelling arthropod assemblages. Keywords: Biodiversity, Dry channel, Riparian and upland habitats, River management, Sediments, Terrestrial invertebrates.

Publication Title:

Journal of Arid Environments

Item Type:
Journal Article

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