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1. Communities across trophic levels, and the functional roles they play, are vital for the sustained provision of ecosystem services. In forest systems, diversification of overstorey composition has been shown to be a key driver of biodiversity, but its influence on across-trophic level relationships remains scarcely known. Species across trophic levels in varied overstorey compositions are also differentially susceptible to fragmentation context. We hypothesise that fragmentation will disrupt community relationships associated with particular overstorey compositions. 2. We test this hypothesis using a tree diversity research platform across 53 deciduous woodland plots in central Belgium. We estimate species' abundances within nine, generally taxonomic, community groups across trophic levels: understorey vegetation; leaf miners and gall formers; woodlice, millipedes; carabid beetles, harvestmen, spiders, birds, bats. We use multiple co-inertia analyses to examine how taxonomic and trophic role community matrices covary across gradients of overstorey composition, via three different tree species diversification pathways, and fragmentation. 3. For all trophic role groups, across all plots, there was at least one significant pairwise comparison. Apart from comparisons involving bats, there was at least one significant pairwise correlation between taxonomic groups too. These results indicate correlated community matrices across trophic levels. Overstorey composition related to community tightness, that is, the level of co-ordinated change among taxonomic and/or trophic role groups as revealed by multiple co-inertia analyses. Notably, diversifying woodlands of beech Fagus sylvatica or red oak Quercus rubra with pedunculate oak Quercus robur correlated with increased taxonomic community tightness. Diversifying pedunculate oak forest stands with other overstorey species related to unchanged community tightness. Evidence was lacking for fragmentation affecting community tightness, singly or by interacting with overstorey composition. 4. Synthesis. Overall, changing tree species composition and fragmentation level affected across-trophic level community relationships differently. Yet, we demonstrated a clear signal that diversifying monoculture stands with particular species correlated with greater community tightness, and co-ordinated change among sets of community groups, across trophic levels and regardless of fragmentation context. We postulate that having tighter community relationships suggests that measures to improve biodiversity at one trophic level (i.e. trees) could affect other groups, and their associated roles, in a co-ordinated manner.

© 2019 The Authors. Diversity and Distributions Published by John Wiley & Sons Ltd Aim: Forests are highly fragmented across Western Europe, making forest edges important features in many agricultural landscapes. Forest edges are subject to strong abiotic gradients altering the forest environment and resulting in strong biotic gradients. This has the potential to change the forest's capacity to provide multiple ecosystem services such as nutrient cycling, carbon sequestration and natural pest control. Soil organisms play a key role in this perspective; however, these taxa are rarely considered in forest edge research. Location: A latitudinal gradient of 2,000 km across Western Europe. Methods: We sampled six dominant taxa of litter-dwelling macro-arthropods (carabid beetles, spiders, harvestmen, centipedes, millipedes and woodlice) in forest edges and interiors of 192 forest fragments in 12 agricultural landscapes. We related their abundance and community composition to distance from the edge and the interaction with forest age, edge orientation and edge contrast (contrast between land use types at either side of the edge). Results: Three out of six macro-arthropod taxa have higher activity-density in forest edges compared to forest interiors. The abundance patterns along forest edge-to-interior gradients interacted with forest age. Forest age and edge orientation also influenced within-fragment compositional variation along the forest edge-to-interior gradient. Edge contrast influenced abundance gradients of generalist predators. In general, older forest fragments, south-oriented edges and edges along structurally more continuous land use (lower contrast between forest and adjacent land use) resulted in stronger edge-to-interior gradients while recent forests, north-oriented edges and sharp land use edges induced similarity between forest edge and interior along the forest edge-to-interior gradients in terms of species activity-density and composition. Main conclusions: Edge effects on litter-dwelling macro-arthropods are anticipated to feedback on important ecosystem services such as nutrient cycling, carbon sequestration and natural pest control from small forest fragments. ispartof: DIVERSITY AND DISTRIBUTIONS vol:25 issue:6 pages:963-974 status: published

Cithaeron dippenaarae sp. n. is described from both sexes. The species occurs in stony regions in the south of Morocco.