The ghosts of forests past and future : deforestation and botanical sampling in the Brazilian Amazon

The remarkable biodiversity of the Brazilian Amazon is poorly documented and threatened by deforestation. When undocumented areas become deforested, in addition to losing the fauna and flora, we lose the opportunity to know which unique species had occupied a habitat. Here we quantify such knowledge loss by calculating how much of the Brazilian Amazon has been deforested and will likely be deforested until 2050 without having its tree flora sufficiently documented. To this end, we analysed 399 147 digital specimens of nearly 6000 tree species in relation to official deforestation statistics and future deforestation scenarios. We find that by 2017, 30% of all the localities where tree specimens had been collected were mostly deforested. Some 300 000 km(2)(12%; 485 25 x 25 km grid cells) of the Brazilian Amazon had been deforested by 2017, without having a single tree specimen recorded. An additional 250 000-900 000 km(2)of severely under-collected rainforest will likely become deforested by 2050. If future tree sampling is to cover this area, sampling effort has to increase two- to six-fold. Nearly 255 000 km(2)or 7% of rainforest in the Brazilian Amazon is easily accessible but does yet but remain under-collected. Our study highlights how progressing deforestation increases the risk of losing undocumented species of a hyper-diverse tree flora.Peer reviewe

The evolution of sexually dimorphic cuticular hydrocarbons in blowflies (Diptera: Calliphoridae)

© 2020 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2020 European Society For Evolutionary Biology Cuticular hydrocarbons (CHCs) are organic compounds found on the cuticles of all insects which can act as close-contact pheromones, while also providing a hydrophobic barrier to water loss. Given their widespread importance in sexual behaviour and survival, CHCs have likely contributed heavily to the adaptation and speciation of insects. Despite this, the patterns and mechanisms of their diversification have been studied in very few taxa. Here, we perform the first study of CHC diversification in blowflies, focussing on wild populations of the ecologically diverse genus Chrysomya. We convert CHC profiles into qualitative and quantitative traits and assess their inter- and intra-specific variation across 10 species. We also construct a global phylogeny of Chrysomya, onto which CHCs were mapped to explore the patterns of their diversification. For the first time, we demonstrate that blowflies express an exceptional diversity of CHCs, which have diversified in a nonphylogenetic and punctuated manner, are species-specific and sexually dimorphic. It is likely that both ecological and sexual selection have shaped these patterns of CHC diversification, and our study now provides a comprehensive framework for testing such hypotheses

Mortality of marine mussels Mytilus edulis and M. galloprovincialis: systematic literature review of risk factors and recommendations for future research

The aim of this study was to summarise the literature reporting the risk factors for mortality in the mussel species Mytilus edulis and Mytilus galloprovincialis in order to identify potential science‐based solutions to prevent or mitigate mussel mortality outbreaks. We followed the PRISMA methodology: Preferred Reporting Items for Systematic Reviews and Meta‐Analyses. The studied corpus of 91 publications (114 studies) was highly heterogeneous with respect to the methodological approaches used to define or estimate mussel mortality and the related putative risk factors. Results showed that the mortality risk of both mussel species M. edulis and M. galloprovincialis varied across the seasons, increased with an elevated seawater temperature above a thermal threshold of 20 and 24°C, respectively, decreased by protecting mussels from predation, and was associated with the presence of pathogens in M. edulis. For M. galloprovincialis, using mussel spat from the same area where the farming is carried out and farming them together with another mussel species appears to reduce the mortality risk. However, for M. edulis, this could be achieved by using pure crosses and in particular mussel spat having a selected genotype. For wild bed conservation, sand accumulation and anthropogenic sedimentation should be minimised. Our analysis showed that current approaches to this research topic are limited and are unlikely to yield actionable evidence to identify mussel mortality prevention or mitigation strategies. Therefore, recommendations are offered to increase the ability of future eco‐epidemiological research to identify multiple exposures associated with mussel mortality, underpinned by standardised efforts and cooperative initiatives