Human activities have altered the species composition of assemblages through introductions and extinctions, but it remains unclear how those changes can affect the different facets of biodiversity. Here we assessed the impact of changes in species composition on taxonomic, functional, and phylogenetic diversity across 281 bird assemblages worldwide. To provide a more nuanced understanding of functional diversity, we distinguished morphological from life-history traits. We showed that shifts in species composition could trigger a global decline in avian biodiversity due to the high number of potential extinctions. Moreover, these extinctions were not random but unique in terms of function and phylogeny at the regional level. Our findings demonstrated that non-native species cannot compensate for these losses, as they are both morphologically and phylogenetically close to the native fauna. In the context of the ongoing biodiversity crisis, such alterations in the functional and phylogenetic structure of bird assemblages could heighten ecosystem vulnerability.

Human activities have altered the composition of species assemblages through the introduction of non-native species and the extinction of threatened species. However, it remains unclear whether non-native species can compensate for the loss of threatened species and thus maintain ecosystem functioning. Here we tested whether non-natives are functionally and/or phylogenetically similar (compensation hypothesis) or distinct (shift hypothesis) from native and threatened species on bird assemblages in 267 regions worldwide. We show that non-native species were more functionally distinct from threatened species than expected by chance but more phylogenetically related. Globally, this results in an increase in the functional richness of bird assemblages due to the introduction of new functional traits but a decrease in the phylogenetic richness due to the potential loss of phylogenetically unique threatened species. Furthermore, these patterns vary across continents, revealing the role of human history and footprint across the world and outlining priority areas where international bird conservation should focus. In the context of the biodiversity crisis and the increasing number of non-native species worldwide, the changes in the functional and phylogenetic structure of the bird communities might increase the vulnerability of ecosystems.

Title: Atopic sensitization in childhood depends on the type of green area around the home in infancy Tiia Voor1,2*, Meelis Pärtel3*, Aleksandr Peet1,2, Liisa Saare1,2, Heikki Hyöty4,5, Mikael Knip6,7, John Davison3, Martin Zobel3#, Vallo Tillmann1,2#1 Children´s Clinic of Tartu University Hospital, Estonia2 Institute of Clinical Medicine, University of Tartu, Estonia3 Institute of Ecology and Earth Sciences, University of Tartu, Estonia4 Faculty of Medicine and Health Technology, Tampere University, Finland5 Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland6 Pediatric Research Center, New Children’s Hospital, Helsinki University Hospital, Helsinki, Finland7 Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, FinlandTo the editor,The prevalence of allergy has increased worldwide (1) and a green environment is essential in developing immune responses and may protect against allergy (2, 3). However, previous studies have not distinguished the effects of different green area types.Here we tested how the type and spatial scale of green area around the infancy home are associated with atopic sensitization up to the age of 9 years.The study group comprised 280 children from the Estonian DIABIMMUNE project birth cohort (4) whose sera were measured for different allergen-specific IgE (sIgE) antibodies at the ages 0.5, 1.5, 3, and 9 years. Subjects were divided into 3 groups by sIgE results. 86 children who had at least one sIgE ≥0.7 kU/L were categorized into the group of definite atopic sensitization (Group I); 44 children had some sIgE between 0.35-0.69 kU/L and were classified as uncertain sensitization (Group II); 150 children had all measured sIgE below 0.35 KU/L, and they formed the control group (Group III). The types of surrounding green areas during the first six months of life were obtained from digital maps of Estonia. The land was divided into agricultural fields, forests, grasslands and wetlands (Figure 1A).The combination of various green area types at a radius of 1-10 km around homes in infancy was related to signs of atopy by ordinal regressions, and model weights were compared.This is the first study addressing the correlation between the land-use intensity around child homes and the development of atopic sensitization. A model with the green areas within 8 km had the highest protective weight (Fig. 1B). Among the various types of green areas, the impact of forests was the largest (Fig. 1C), but the best model also included grasslands and wetlands. Agricultural fields had an impact only at 1-2 km scales, and their weight declined strongly at larger scales (Table 1). We used the best model (area of forest, grasslands and wetlands within 8 km) and examined how it predicts atopic sensitization groups (Fig. 1D). The model predicted a decrease in Group I and an increase in control Group III. The uncertain Group II showed a slightly decreasing tendency. The protective effect of forests, grasslands and wetlands against sensitization was evident for both inhaled and food allergens.The world is urbanizing, and the isolation of humans from biodiverse green areas leads to reduced contact with beneficial environmental microbes (5). Ruokalainen et al (2) showed that the greenness around homes was negatively associated with the risk of atopy in children. Contact with natural soil enriched microbiota enhanced immune regulation and may reduce the risk of development of immune-mediated diseases (6). Our results reveal considerable differences in how various green area types might prevent atopic sensitization. The area of biodiverse land (forests, grasslands, wetlands) showed a strong protective effect, while the agricultural land did not. The positive effect of forests, grasslands and wetlands became clearer with increasing spatial scale. The relatively large distance of influence indicates that the biodiversity of beneficial microbes might need a large area.Our study has some limitations. First, we could not study the microbiota of the participants and determine whether the spatial environmental model explained microbiota composition. Secondly, we studied only atopic sensitization and did not diagnose allergic disease. This was because the data were collected using questionnaires completed by parents and were of variable quality.In conclusion, the current results indicate that biodiverse land – such as forests, grasslands, and wetlands – around homes during infancy elicits a strong protective effect against the development of atopy later in childhood. At the same time, intensive croplands have only a very weak effect.

Phenotypic plasticity can mask population genetic differentiation, reducing the predictability of trait-environment relationships. In short-lived plants, reproductive traits may be more genetically determined due to their direct impact on fitness, whereas vegetative traits may show higher plasticity to buffer short-term perturbations. Combining a multi-treatment greenhouse experiment with global field observations for the short-lived Plantago lanceolata, we 1) disentangled the genetic and plastic responses of functional traits to a set of environmental drivers and 2) assessed the utility of trait-environment relationshisps inferred from observational data for predicting genetic differentiation. Reproductive traits showed distinct genetic differentiation that was highly predictable from observational data, but only when correcting traits for differences in their (labile) biomass component. Vegetative traits showed higher plasticity and contrasting genetic and plastic responses, leading to unpredictable trait patterns. Our study suggests that genetic differentiation may be inferred from observational data only for the traits most closely related with fitness.