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The purpose of the present study was to evaluate the clinical and radiographic outcomes of the number of microthreads on marginal bone over 5 years. Thirty-two implants were placed in 32 patients with partially edentulous maxillae or mandibles. Two implants with the same characteristics were placed: the first one had a 1 mm crest module and 3 microthreads (Q); and the second one had a 3 mm crest module and nine microthreads (S). The prosthesis was inserted 3 months after implant placement. Clinical and radiographic examinations were performed at the one-week, one-month, and three-month follow-up visits and then every six months until a five-year follow-up period was completed. After 5 years of follow-up, five patients withdrew from the study. Complete data were available for 27 implants, with a 100% implant survival rate. No cases of peri-implantitis were diagnosed. The average bone loss was 0.65 mm (C.I. 0.21–1.09) for Q implants and 0.86 mm (C.I. 0.39–1.33) for S implants, with no statistically significant difference. The bone level does not vary between implants with three and nine microthreads or with a 1 mm and 3 mm crest module. No differences in clinical parameters were found.

Abstract Revealing the effects of multiple global change drivers on ecosystem dynamics and functioning is a crucial endeavour, which necessitates the use of appropriate tools. Here, we present the Aquatic Metatron, a unique mesocosm facility providing a large‐scale experimental resource to study the combined effects of global change components, in particular climate change and habitat fragmentation, on the ecological and evolutionary dynamics of aquatic ecosystems. The Aquatic Metatron consists of 144 mesocosms of 2 m3 each that can be connected to each other with aquatic corridors, and—for a subset of them—with aerial corridors. This enables effective control of dispersal across meta‐ecosystems. In addition, the temperature in each mesocosm is supervised and precisely controlled, either through a heating (all mesocosms) or a cooling (72 mesocosms) system. All mesocosms can be monitored automatically for abiotic and biotic factors (pH, dissolved oxygen, conductivity, turbidity and chlorophyll a) allowing for long‐term experimentation. We tested the platform by conducting three experiments involving the manipulation of various components of global change: climate warming, biodiversity loss, eutrophication and aquatic/aerial fragmentation. The technical innovations of the platform have been validated, in particular its capacity to accurately recreate multiple climatic scenarios (e.g. heatwaves, warming, cooling) and the possibility of using aerial and water corridors to simulate fragmented landscapes. The Aquatic Metatron is located in the south‐west of France (https://sete‐moulis‐cnrs.fr/fr) and is part of AnaEE France and AnaEE‐ERIC (https://www.anaee.eu/), which are large‐scale research infrastructures. The Aquatic Metatron is a research facility accessible to external researchers and projects.

Abstract Microplastics pervade ocean ecosystems. Despite their effects on individuals or populations are well documented, the consequences of microplastics on ecosystem functioning are still largely unknown. Here, we show how microplastics alter the structure and functioning of pelagic microbial ecosystems. Using experimental pelagic mesocosms, we found that microplastics indirectly affect marine productivity by changing the bacterial and phytoplankton assemblages. Specifically, the addition of microplastics increased phytoplankton biomass and shifted bacterial assemblages' composition. Such changes altered the interactions between heterotrophic and autotrophic microbes and the cycling of ammonia in the water column, which ultimately benefited photosynthetic efficiency. The effects of microplastics on marine productivity were consistent for different microplastic types. This study demonstrates that microplastics affect bacteria and phytoplankton communities and influence marine productivity, which ultimately alters the functioning of the whole ocean ecosystem.

Habitat loss could affect ecological communities in variable ways depending on its structure. Here, the authors show that contiguous rather than random loss is more damaging to the stability of multitrophic communities, regardless of the fraction of mutualistic interactions within the community.

Lurgi et al. analyse the distribution of microbial symbionts across many sponge species and reveal modules of non-random associations which are primarily driven by host features and microbial phylogenies, and less by the environment. Results also show that metabolic functions are distinct across modules.

Sponges are early-diverging marine organisms that establish complex symbioses with microorganisms. Here, Thomas et al.analyse the microbial communities associated with 81 species of sponges from around the world, shedding light on the ecological and evolutionary drivers of these host-microbe associations.

Loss in intraspecific diversity can alter ecosystem functions, but the underlying mechanisms are still elusive, and intraspecific biodiversity-ecosystem function (iBEF) relationships have been restrained to primary producers. Here, we manipulated genetic and functional richness of a fish consumer (Phoxinus phoxinus) to test whether iBEF relationships exist in consumer species and whether they are more likely sustained by genetic or functional richness. We found that both genotypic and functional richness affected ecosystem functioning, either independently or interactively. Loss in genotypic richness reduced benthic invertebrate diversity consistently across functional richness treatments, whereas it reduced zooplankton diversity only when functional richness was high. Finally, losses in genotypic and functional richness altered functions (decomposition) through trophic cascades. We concluded that iBEF relationships lead to substantial top-down effects on entire food chains. The loss of genotypic richness impacted ecological properties as much as the loss of functional richness, probably because it sustains "cryptic" functional diversity.

Phytoplankton are key components of aquatic ecosystems, fixing CO2 from the atmosphere through photosynthesis and supporting secondary production, yet relatively little is known about how future global warming might alter their biodiversity and associated ecosystem functioning. Here, we explore how the structure, function, and biodiversity of a planktonic metacommunity was altered after five years of experimental warming. Our outdoor mesocosm experiment was open to natural dispersal from the regional species pool, allowing us to explore the effects of experimental warming in the context of metacommunity dynamics. Warming of 4°C led to a 67% increase in the species richness of the phytoplankton, more evenly-distributed abundance, and higher rates of gross primary productivity. Warming elevated productivity indirectly, by increasing the biodiversity and biomass of the local phytoplankton communities. Warming also systematically shifted the taxonomic and functional trait composition of the phytoplankton, favoring large, colonial, inedible phytoplankton taxa, suggesting stronger top-down control, mediated by zooplankton grazing played an important role. Overall, our findings suggest that temperature can modulate species coexistence, and through such mechanisms, global warming could, in some cases, increase the species richness and productivity of phytoplankton communities.