Jesús Miñano

TL;DR: In this article, the relative effects of compositional and configurational crop heterogeneity on within-field plant diversity components were investigated using a dataset from a cross-continent collaborative project covering 1,451 agricultural fields within 432 landscapes in Europe and Canada.

Abstract: Intermittent streams are dynamic ecosystems that alternate between dry and wet states. Despite their global dominance, we have scant information about the effects of surface flow drying on terrestrial arthropods in channel and adjacent terrestrial habitats. In the present study, we used pitfall traps to characterise the terrestrial arthropod assemblages along lateral gradients (channel, riparian, and upland habitats) in perennial and intermittent reaches of two contrasting Mediterranean intermittent streams (Rogativa and Fuirosos streams). Simultaneously, we assessed changes in assemblage composition and structure on five sampling occasions over the entire drying period (i.e. 29 days). The composition of arthropod assemblages differed among streams, flow regimes, habitat types, and sampling dates. In contrast, depending on the stream, taxonomic richness and total abundance were similar between perennial and intermittent reaches, but differed among habitat types. Formicidae, Araneae, Collembola, and Coleoptera explained most of the differences between flow regimes and habitat types in both streams. In Rogativa stream, arthropod abundances peaked in the dry channel and increased with drying time, while abundances decreased in riparian and upland habitats. It implies that the dry channel may be colonized by riparian and upland arthropods to a greater or lesser extent depending on the stream and the specific landscape context. Our results emphasize the importance of dry channels as temporary habitats for terrestrial arthropod assemblages. Thus, the dry period should be considered explicitly when assessing biodiversity of and establishing management strategies for intermittent streams and their fringing riparian and upland areas. Copyright © 2016 John Wiley & Sons, Ltd.

TL;DR: Spiders were generally more abundant and had a higher richness of genera in the low-intensity spraying than in conventional orchards, which suggests that the impact of pesticides on spider could be explained, at least in part, by their foraging mode.