Recent reports on local extinctions of arthropod species1 and of massive declines in arthropod biomass 2 point to land-use intensification as a major driver of decreasing biodiversity. However, there are no multi-site time-series of arthropod occurrences across land-use intensity gradients to confirm causal relationships. Moreover, it remains unclear which land-use types and arthropod groups are affected and whether the observed declines in biomass and diversity are linked to one another and continue. Here we analyzed arthropod data on more than 1 million individuals and 2,700 species from standardized inventories from 2008 to 2017 at 150 grassland and 140 forest sites in three regions of Germany. Overall gamma diversity in grasslands and forests decreased over time indicating loss of species across sites and regions. In annually sampled grasslands, biomass, abundance and species number of arthropods declined by 67%, 78%, and 34%, respectively. The decline was consistent across trophic levels, mainly affected rare species, and its magnitude was independent of local land-use intensity. However, sites embedded in landscapes with higher cover of agricultural land showed a stronger temporal decline. In 30 forest sites with annual inventories, biomass and species number, but not abundance, decreased by 41% and 36%, respectively. This was supported by analyses of all forest sites sampled in 3year intervals. The decline affected rare and abundant species and trends differed across trophic levels. Our results show that there are widespread declines in arthropods that concern biomass, abundance and diversity across trophic levels. Declines in forests demonstrate that arthropod loss is not restricted to open habitats. Our results 4 suggest that major drivers of arthropod decline act at larger spatial scales, and are, at least for grasslands, associated with agriculture at the landscape level.This implies that land-use relevant policies need to address the landscape scale to mitigate negative effects of land-use practices. Main textMuch of the debate on the human-induced biodiversity crisis has focused on vertebrates 3 , yet population decline and extinctions may be even more substantial in small organisms such as terrestrial arthropods 4 . Recent studies report declines in biomass of flying insects 2 , diversity of insect pollinators 5,6 , butterflies and moths 1,7-10 , hemipterans 11,12 and beetles 7,13,14 . Owing to the associated negative effects on food webs 15 , ecosystem functioning and ecosystem services 16 , the insect loss has spurred an intense public debate. However, time-series data on arthropods are rather limited and studies have so far focused on a small range of taxa 11,13,14 , few land-use and habitat types 12 or even on single sites 1,17 . In addition, many studies lack species information 2 or high temporal resolution 2,12 . Hence, it remains unclear whether reported declines in arthropods are a general phenomenon that is driven by similar mechanisms across land-use types, taxa and functional groups.The ...

No abstract

Biodiversity is not homogenously distributed over the globe, and ecosystems differ strongly in the number of species they provide. With this special issue we highlight the ecology and endangerment of one of the most diverse ecosystem of Europe: the European grassland ecosystems. The selected 16 contributions describe interactions from below-ground to the atmosphere and focus on (1) effects of abiotic and biotic on species diversity, (2) the impact of various factors along spatial and temporal gradients, (3) the

Recently, many new (extant) mammal species have been named, mostly by raising subspecies to species rank. This is primarily a consequence of the phylogenetic species concept (PSC) that has become very popular over the last few decades. We highlight several cases of splitting and argue that much of this taxonomic inflation is artificial due to shortcomings of the PSC and unjustified reliance on insufficient morphological and/or genetic data. We particularly discourage species splitting based on gene trees inferred from mitochondrial DNA only and phenetic analyses aimed at diagnosability. Uncritical acceptance of new species creates an unnecessary burden on the conservation of biodiversity

No abstract

No abstract

Environmental changes strongly impact the distribution of species and subsequently the composition of species assemblages. Although most community ecology studies represent temporal snap shots, long-term observations are rather rare. However, only such time series allow the identification of species composition shifts over several decades or even centuries. We analyzed changes in the species composition of a southeastern German butterfly and burnet moth community over nearly 2 centuries (1840-2013). We classified all species observed over this period according to their ecological tolerance, thereby assessing their degree of habitat specialisation. This classification was based on traits of the butterfly and burnet moth species and on their larval host plants. We collected data on temperature and precipitation for our study area over the same period. The number of species declined substantially from 1840 (117 species) to 2013 (71 species). The proportion of habitat specialists decreased, and most of these are currently endangered. In contrast, the proportion of habitat generalists increased. Species with restricted dispersal behavior and species in need of areas poor in soil nutrients had severe losses. Furthermore, our data indicated a decrease in species composition similarity between different decades over time. These data on species composition changes and the general trends of modifications may reflect effects from climate change and atmospheric nitrogen loads, as indicated by the ecological characteristics of host plant species and local changes in habitat configuration with increasing fragmentation. Our observation of major declines over time of currently threatened and protected species shows the importance of efficient conservation strategies.

Aim In contrast to the attention given to southern Europe both as a centre of speciation and differentiation and as a Pleistocene refugium of Western Palaearctic taxa, North Africa has been relatively neglected. In this paper, we set out to address this shortfall.Location North-West Africa and the Mediterranean.Methods We reviewed the existing literature on the biogeography of North Africa, and carried out analyses of species distribution data using parsimony, nestedness and co-occurrence methods.Results In many cases, distribution patterns of non-flying mammals, bats, amphibians, reptiles, butterflies, zygaenid moths and odonates demonstrated important biogeographical affinities between Europe and North Africa at the species level. On the other hand, species co-occurrence, nestedness and parsimony analysis also revealed some deep splits between the Maghreb and Europe; yet even in these cases the closest affinities were found between the Iberian Peninsula and the Maghreb. Furthermore, North Africa harbours the highest proportion of endemic taxa (13.7%) across all groups analysed. Many molecular studies demonstrated a strong genetic cohesiveness between North Africa and Europe despite the potential barrier effect of the Mediterranean Sea. In other taxa, however, remarkable splits were detected. In addition, southern European genetic lineages were often nested within North African clades, and many taxa showed exceptionally high genetic variability and differentiation in this region. Main conclusionsThe Maghreb was an important differentiation and speciation centre for thermophilic organisms during the Pliocene and Pleistocene with high relevance as a colonization source for Europe. The regions around the sea straits of Gibraltar and Sicily have acted as important biogeographical links between North Africa and Europe at different times.