A database and synthesis of euglossine bee assemblages collected at fragrance baits

Euglossine bees are an ecologically important group, which due to their diverse resource needs act as pollinators of many neotropical plants. Male euglossines collect fragrant compounds used in mating displays from diverse sources, including the flowers of orchids and other plants. This aspect of euglossine biology has proven exceptionally useful for studies of euglossine bee populations, because male bees can be readily attracted to fragrance baits deployed in natural habitats. We synthesise the data accumulated over the 50 years since the introduction of euglossine bee baiting inventories and make these data openly available in the EUGCOMM database. By fitting hierarchical joint species distribution models to presence-absence and abundance data, we reveal that the assemblages of bees attracted depend on the baits used in interaction with species-specific fragrance preferences and that bee assemblages are most diverse at sites in landscapes characterised by partial but not complete forest cover. We suggest that these results reflect the diverse resource needs of euglossine bees and are consistent with the hypothesis that male euglossines establish home ranges incorporating multiple habitat types. These results may have important consequences for the design of nature reserves in the tropics, if these iconic pollinators are to be conserved for the future.Peer reviewe

Co-occurrences of tropical trees in eastern South America : disentangling abiotic and biotic forces

Species co-occurrences in local communities can arise independent or dependent on species' niches. However, the role of niche-dependent processes has not been thoroughly deciphered when generalized to biogeographical scales, probably due to combined shortcomings of data and methodology. Here, we explored the influence of environmental filtering and limiting similarity, as well as biogeographical processes that relate to the assembly of species' communities and co-occurrences. We modelled jointly the occurrences and co-occurrences of 1016 tropical tree species with abundance data from inventories of 574 localities in eastern South America. We estimated species co-occurrences as raw and residual associations with models that excluded and included the environmental effects on the species' co-occurrences, respectively. Raw associations indicate co-occurrence of species, whereas residual associations indicate co-occurrence of species after accounting for shared responses to environment. Generally, the influence of environmental filtering exceeded that of limiting similarity in shaping species' co-occurrences. The number of raw associations was generally higher than that of the residual associations due to the shared responses of tree species to the environmental covariates. Contrary to what was expected from assuming limiting similarity, phylogenetic relatedness or functional similarity did not limit tree co-occurrences. The proportions of positive and negative residual associations varied greatly across the study area, and we found a significant tendency of some biogeographical regions having higher proportions of negative associations between them, suggesting that large-scale biogeographical processes limit the establishment of trees and consequently their co-occurrences.Peer reviewe

Pathways towards a sustainable future envisioned by early-career conservation researchers

Scientists have warned decision-makers about the severe consequences of the global environmental crisis since the 1970s. Yet ecological degradation continues and little has been done to address climate change. We investigated early-career conservation researchers' (ECR) perspectives on, and prioritization of, actions furthering sustainability. We conducted a survey (n = 67) and an interactive workshop (n = 35) for ECR attendees of the 5th European Congress of Conservation Biology (2018). Building on these data and discussions, we identified ongoing and forthcoming advances in conservation science. These include increased transdisciplinarity, science communication, advocacy in conservation, and adoption of a transformation-oriented social-ecological systems approach to research. The respondents and participants had diverse perspectives on how to achieve sustainability. Reformist actions were emphasized as paving the way for more radical changes in the economic system and societal values linked to the environment and inequality. Our findings suggest that achieving sustainability requires a strategy that (1) incorporates the multiplicity of people's views, (2) places a greater value on nature, and (3) encourages systemic transformation across political, social, educational, and economic realms on multiple levels. We introduce a framework for ECRs to inspire their research and practice within conservation science to achieve real change in protecting biological diversity

Ecological barriers mediate spatiotemporal shifts of bird communities at a continental scale

This study was supported by the Swiss National Science Foundation (grant P2BEP3_195232) and by the Academy of Finland (project 323527 and project 329251).Species' range shifts and local extinctions caused by climate change lead to community composition changes. At large spatial scales, ecological barriers, such as biome boundaries, coastlines, and elevation, can influence a community's ability to shift in response to climate change. Yet, ecological barriers are rarely considered in climate change studies, potentially hindering predictions of biodiversity shifts. We used data from two consecutive European breeding bird atlases to calculate the geographic distance and direction between communities in the 1980s and their compositional best match in the 2010s and modeled their response to barriers. The ecological barriers affected both the distance and direction of bird community composition shifts, with coastlines and elevation having the strongest influence. Our results underscore the relevance of combining ecological barriers and community shift projections for identifying the forces hindering community adjustments under global change. Notably, due to (macro)ecological barriers, communities are not able to track their climatic niches, which may lead to drastic changes, and potential losses, in community compositions in the future.Publisher PDFPeer reviewe

Pathways towards a sustainable future envisioned by early-career conservation researchers

Scientists have warned decision-makers about the severe consequences of the global environmental crisis since the 1970s. Yet ecological degradation continues and little has been done to address climate change. We investigated early-career conservation researchers' (ECR) perspectives on, and prioritization of, actions furthering sustainability. We conducted a survey (n = 67) and an interactive workshop (n = 35) for ECR attendees of the 5th European Congress of Conservation Biology (2018). Building on these data and discussions, we identified ongoing and forthcoming advances in conservation science. These include increased transdisciplinarity, science communication, advocacy in conservation, and adoption of a transformation-oriented social–ecological systems approach to research. The respondents and participants had diverse perspectives on how to achieve sustainability. Reformist actions were emphasized as paving the way for more radical changes in the economic system and societal values linked to the environment and inequality. Our findings suggest that achieving sustainability requires a strategy that (1) incorporates the multiplicity of people's views, (2) places a greater value on nature, and (3) encourages systemic transformation across political, social, educational, and economic realms on multiple levels. We introduce a framework for ECRs to inspire their research and practice within conservation science to achieve real change in protecting biological diversity.</p

Viability selection creates negative heterozygosity–fitness correlations in female Black Grouse Lyrurus tetrix

There is widespread interest in the relationship between individual genetic diversity and fitness–related traits (heterozygosity–fitness correlations, HFC). Most studies found weak continuous increases of fitness with increasing heterozygosity while negative HFC have rarely been reported. Negative HFC are expected in cases of outbreeding depression and outbreeding is rare in natural populations; but negative HFC may also arise through viability selection acting on low heterozygosity individuals at an early stage producing a skew in the heterozygosity distribution leading to negative HFCs. We tested this idea using survival and clutch parameters (egg mass, egg volume, chick mass, clutch size) collected in female black grouse Lyrurus tetrix and carried out simulations to determine how survival selection may impact the HFCs measured using clutch parameters. We show that survival is positively related to both individual heterozygosity and female body mass. There is a positive effect of body mass on all clutch parameters, but the selective mortality of females with both low heterozygosity and low body mass led to over representation of high heterozygosity-low body mass females and hence a negative relationship between egg volume and heterozygosity. Using simulated data, we show that survival selection acting on both low body mass and low heterozygosity leads to a skew in the quality of females breeding, resulting in negative HFCs with egg volume. Our results indicate that survival selection can strongly influence the strength and direction of any HFC that occur later in life and that only an integration of all aspects of individuals’ reproductive investment and reproductive success can enable us to fully understand how heterozygosity can shape individual’s fitness

Viability selection creates negative heterozygosity–fitness correlations in female Black Grouse Lyrurus tetrix

There is widespread interest in the relationship between individual genetic diversity and fitness–related traits (heterozygosity–fitness correlations, HFC). Most studies found weak continuous increases of fitness with increasing heterozygosity while negative HFC have rarely been reported. Negative HFC are expected in cases of outbreeding depression and outbreeding is rare in natural populations; but negative HFC may also arise through viability selection acting on low heterozygosity individuals at an early stage producing a skew in the heterozygosity distribution leading to negative HFCs. We tested this idea using survival and clutch parameters (egg mass, egg volume, chick mass, clutch size) collected in female black grouse Lyrurus tetrix and carried out simulations to determine how survival selection may impact the HFCs measured using clutch parameters. We show that survival is positively related to both individual heterozygosity and female body mass. There is a positive effect of body mass on all clutch parameters, but the selective mortality of females with both low heterozygosity and low body mass led to over representation of high heterozygosity-low body mass females and hence a negative relationship between egg volume and heterozygosity. Using simulated data, we show that survival selection acting on both low body mass and low heterozygosity leads to a skew in the quality of females breeding, resulting in negative HFCs with egg volume. Our results indicate that survival selection can strongly influence the strength and direction of any HFC that occur later in life and that only an integration of all aspects of individuals’ reproductive investment and reproductive success can enable us to fully understand how heterozygosity can shape individual’s fitness