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As cities become more populated and the density of urban development increases, local biodiversity is threatened. Urban greenspaces have the capacity to preserve pollinator biodiversity, but the quality of support they provide depends on greenspace landscape attributes, including the availability of pollinator habitat and foraging resources. Wild native bees provide important pollination services to urban ecosystems, yet relatively little is known about how urban landscape management influences pollinator community composition and diversity. Our study explores how wild bee communities are affected by greenspace and landscape-level features like pollinator management practices, in urban greenspaces in and around Appleton Wisconsin: a mid-sized urban community spanning more than 100 sq. km. We sampled and identified native bees periodically between late-May 2017 and mid-September of 2018 using standardized arrays of pan traps at 15 sites around the city. We classified greenspaces based on their level of development (urban or suburban) and whether they were managed or unmanaged for increasing wild pollinator diversity. We quantified floral species diversity, floral color diversity, tree species diversity, and proximity of sites to open water for each site and used remotely sensed satellite data from both the USGS National Land Cover Database (NLCD) and the Normalized Difference Vegetation Index (NDVI). All variables were tested as potential correlates of wild bee abundance and species richness. Active pollinator management sites supported higher levels of bee abundance and richness. Notably, active greenspace management (e.g. planting native wildflowers) was a stronger correlate of bee abundance and richness than greenspace size and other landscape-level attributes. Within-greenspace attributes such as floral diversity, tree diversity, and proximity to open water contributed positively to both bee abundance and richness. Based on these findings, we suggest that urban greenspaces may be managed more efficiently and cost-effectively by focusing resources on active management by planting wildflowers, removing invasive species, creating nesting habitat, and providing water resources, rather than simply expanding in area. [ABSTRACT FROM AUTHOR]

The increase in species diversity from temperate to tropical regions is one of the most widespread patterns in biogeography. As humans continue to drastically modify natural habitats, land‐use changes such as the development of cities could potentially alter typical latitudinal diversity gradients. Cities could depress or enhance biodiversity through filtering, localised extirpations, or increasing niche availability, respectively.To address these possibilities and the consequences for the latitudinal diversity gradient, we constructed a global dataset of urban species diversity (richness) and community composition across ~60° of absolute latitude and from 63 cities. We focused our study on ants, for which comparable urban and non‐urban diversity data are broadly available.We found that urbanisation significantly dampened the latitude‐diversity cline. The effects of urbanisation varied with latitude: at lower latitudes, cities were relatively species poor and harboured distinct ant communities relative to nearby non‐urban communities. In higher latitude cities, both species richness and community composition were more similar to the surrounding non‐urban ant communities.Our analyses suggest that the strongest impacts of urbanisation on ant diversity may be in the tropics, where biological diversity is already expected to experience the greatest risk of extinction in the face of climate change. [ABSTRACT FROM AUTHOR]

No Mow May is a community science initiative popularized in recent years that encourages property owners to limit their lawn mowing practices during the month of May. The goal of No Mow May is to provide early season foraging resources for pollinators that emerge in the spring, especially in urban landscapes when few floral resources are available. We worked with the city council of Appleton, Wisconsin, USA. to allow No Mow May to take place in May 2020. Four hundred and thirty- five property owners registered for No Mow May in Appleton. We measured floral and bee richness and abundance in the yards of a subset of homes (N D20) located near regularly mowed urban parks (N D15) at the end of the month. We found that homes that participated in No Mow May had more diverse and abundant flora than regularly mowed green spaces throughout the city. No Mow May homes had three times higher bee richness and five times higher bee abundances than frequently mowed greenspaces. Using generalized linear models, we found that the best predictor of bee richness was the size of the designated unmowed area, and the best predictors of bee abundances were the size of the unmowed area as well as floral richness. While our findings cannot conclusively attribute increases in bee abundances and richness to the No Mow May efforts, our data does show that bee pollinators make use of no mow spaces as key floral resources during early spring in the upper midwestern United States. A post-No Mow May survey revealed that the participants were keen to increase native floral resources in their yards, increase native bee nesting habitat, reduce mowing intensities, and limit herbicide, pesticide, and fertilizer applications to their lawns. The No Mow May initiative educated an engaged community on best practices to improve the conservation of urban pollinators in future years. [ABSTRACT FROM AUTHOR]

We use observed patterns of species richness and composition of ant communities along a 1000 mm rainfall gradient in northern Australian savanna to assess the accuracy of species richness and turnover predictions derived from stacked species distribution models (S‐SDMs) and constrained by macroecological models (MEMs). We systematically sampled ants at 15 sites at 50 km intervals along the rainfall gradient in 2012 and 2013. Using the observed data, we created MEMs of species richness, composition and turnover. We built distribution models for 135 of the observed species using data from museum collections and online databases. We compared two approaches of stacking SDMs and three modelling algorithms to identify the most accurate way of predicting richness and composition. We then applied the same beta diversity metrics to compare the observed versus predicted patterns. Stacked SDMs consistently over‐predicted local species richness, and there was a mismatch between the observed pattern of richness estimated from the MEM, and the pattern predicted by S‐SDMs. The most accurate richness and turnover predictions occurred when the stacked models were rank‐ordered by their habitat suitability and constrained by the observed MEM richness predictions. In contrast with species richness, the predictions obtained by the MEM of community similarity, composition and turnover matched those predicted by the S‐SDMs. S‐SDMs regulated by MEMs may therefore be a useful tool in predicting compositional patterns despite being unreliable estimators of species richness. Our results highlight that the choice of species distribution model, the stacking method used, and underlying macroecological patterns all influence the accuracy of community assembly predictions derived from S‐SDMS. [ABSTRACT FROM AUTHOR]

Aim Using a standardized sampling protocol along a 600-km transect in northern Australia, we tested whether ant diversity within a single biome, tropical savanna, decreases with increasing latitude (as a surrogate of temperature) and decreasing rainfall, as is expected for biodiversity in general. Location Northern Australia. Methods Ants were sampled using pitfall traps on three occasions at 1-ha sand, loam and clay sites at each of five locations along the Northern Australian Tropical Transect (NATT), from 12°500 S (1400 mm mean annual rainfall) to 17°210 S (650 mm). Results We recorded a total of 246 species from 37 genera. Mean observed species richness pooled across sampling periods was similar at sand (85.4) and loam (82.2) sites, but was less than half this at clay sites (40.0). Ant communities were also compositionally distinct on clay soils compared with sands and loams. Individual genera showed variable diversity patterns, ranging from a linear increase to a linear decrease in species richness along the NATT. However, total species richness was relatively uniform along the gradient. Patterns of ant species turnover were consistent with previously recognized biogeographical boundaries, with a primary disjunction between the arid and monsoonal zones in the south, and a secondary disjunction between the semi-arid and mesic zones in the north. Main conclusions Patterns of ant diversity in Australian savannas do not conform to global patterns of biodiversity declines with increasing latitude and decreasing rainfall. We believe this is due to a lack of significant temperature change across the latitudinal gradient, and, in particular, to the fauna's evolutionary history in association with aridification, which makes it unusually resilient to increasing aridity. The diversity of other important faunal groups such as termites and lizards is also exceptionally high in arid Australia and is likewise not closely linked to rainfall in Australian savannas. We predict that these taxa are far more sensitive to increasing aridity in savannas elsewhere in the world, and especially in the Neotropics, where savannas have an evolutionary association with humid rain forest rather than desert. [ABSTRACT FROM AUTHOR]

Aim Using a standardized sampling protocol along a 600-km transect in northern Australia, we tested whether ant diversity within a single biome, tropical savanna, decreases with increasing latitude (as a surrogate of temperature) and decreasing rainfall, as is expected for biodiversity in general. Location Northern Australia. Methods Ants were sampled using pitfall traps on three occasions at 1-ha sand, loam and clay sites at each of five locations along the Northern Australian Tropical Transect (NATT), from 12°50' S (1400 mm mean annual rainfall) to 17°21' S (650 mm). Results We recorded a total of 246 species from 37 genera. Mean observed species richness pooled across sampling periods was similar at sand (85.4) and loam (82.2) sites, but was less than half this at clay sites (40.0). Ant communities were also compositionally distinct on clay soils compared with sands and loams. Individual genera showed variable diversity patterns, ranging from a linear increase to a linear decrease in species richness along the NATT. However, total species richness was relatively uniform along the gradient. Patterns of ant species turnover were consistent with previously recognized biogeographical boundaries, with a primary disjunction between the arid and monsoonal zones in the south, and a secondary disjunction between the semi-arid and mesic zones in the north. Main conclusions Patterns of ant diversity in Australian savannas do not conform to global patterns of biodiversity declines with increasing latitude and decreasing rainfall. We believe this is due to a lack of significant temperature change across the latitudinal gradient, and, in particular, to the fauna's evolutionary history in association with aridification, which makes it unusually resilient to increasing aridity. The diversity of other important faunal groups such as termites and lizards is also exceptionally high in arid Australia and is likewise not closely linked to rainfall in Australian savannas. We predict that these taxa are far more sensitive to increasing aridity in savannas elsewhere in the world, and especially in the Neotropics, where savannas have an evolutionary association with humid rain forest rather than desert. [ABSTRACT FROM AUTHOR]

Direct and indirect consequences of global warming on ecosystem functions and processes mediated by invertebrates remain understudied but are likely to have major impacts on ecosystems in the future. Among animals, invertebrates are taxonomically diverse, responsive to temperature changes, and play major ecological roles which also respond to temperature changes., We used a mesocosm experiment to evaluate impacts of two warming treatments (+3·5 and +5 °C, set-points) and the presence and absence of the ant Formica subsericea (a major mediator of processes in north temperate ecosystems) on decomposition rate, soil movement, soil respiration and nitrogen availability., Replicate 19-L mesocosms were placed outdoors in lathe houses and continuously warmed for 30 days in 2011 and 85 days in 2012. Warming treatments mimicked expected temperature increases for future climates in eastern North America., In both years, the amount of soil displaced and soil respiration increased in the warming and ant presence treatments (soil movement: 73-119%; soil respiration: 37-48% relative to the control treatments without ants)., Decomposition rate and nitrogen availability tended to decrease in the warmest treatments (decomposition rate: −26 to −30%; nitrate availability: −11 to −42%)., Path analyses indicated that ants had significant short-term direct and indirect effects on the studied ecosystem processes. These results suggest that ants may be moving more soil and building deeper nests to escape increasing temperatures, but warming may also influence their direct and indirect effects on soil ecosystem processes. [ABSTRACT FROM AUTHOR]

Aims Climatic change is expected to rearrange species assemblages and ultimately affect organism-mediated ecosystem processes. We focus on identifying patterns and relationships between common ant species (representing 99% of total ant records) richness and functional diversity; modelling how these patterns may change at local and regional scales in future climatic conditions; and interpreting how these changes might influence ant-mediated ecosystem processes. Location Forested ecosystems of eastern North America. Methods We used a previously published dataset to evaluate functional diversity at 67 sites in the eastern U.S. and quantified 14 taxonomic, morphometric and natural history traits for 70 common ant species in the region. We used functional diversity metrics, functional groups and species distribution modelling methods to address our aims. We used stacked species distribution models and stacked functional group models to predict species assemblages and functional richness at the 67 sites and at a regional scale for current and future climatic conditions. Results Species richness and functional diversity are positively correlated throughout the region. Under future climate scenarios, species richness and functional group richness were predicted to decrease in southern ecoregions and increase in northern ecoregions. This may be due to increased thermal stress for species in the southern extent of their ranges and increased habitat suitability in the northern ecoregions. Decomposers, arthropod community regulators and seed dispersers are forecast to be the most threatened ant functional groups. Main Conclusions Climate change will likely lead to major changes in ant species richness and functional group richness in the forests of the north-eastern United States, and this may substantially alter ant-mediated ecosystem processes and services. [ABSTRACT FROM AUTHOR]

Insect mutualisms can have disproportionately large impacts on local arthropod and plant communities and their responses to climatic change. The objective of this study was to determine if the presence of insect mutualisms affects host plant and herbivore responses to warming. Using open-top warming chambers at Harvard Forest, Massachusetts, USA, we manipulated temperature and presence of ants and Chaitophorus populicola aphids on Populus tremuhides host plants and monitored ant attendance and persistence of C. populicola, predator abundance, plant stress, and abundance of Myzus persicae, a pest aphid that colonized plants during the experiment. We found that, regardless of warming, C. populicola persistence was higher when tended by ants, and some ant species increased aphid persistence more than others. Warming had negligible direct but strong indirect effects on plant stress. Plant stress decreased with warming only when both ants and C. populicola aphids were present and engaged in mutualism. Plant stress was increased by warming-induced reductions in predator abundance and increases in M. persicae aphid abundance. Altogether, these findings suggest that insect mutualisms could buffer the effects of warming on specialist herbivores and plants, but when mutualisms are not intact, the direct effects of warming on predators and generalist herbivores yield strong indirect effects of warming on plants. [ABSTRACT FROM AUTHOR]

Studies of species diversity patterns across regional environmental gradients seldom consider the impact of habitat type on within-site (alpha) and between-site (beta) diversity. This study is designed to identify the influence of habitat type across geographic and environmental space, on local patterns of species richness and regional turnover patterns of ant diversity in the northeastern United States. Specifically, I aim to 1) compare local species richness in paired open and forested transects and identify the environmental variables that best correlate with richness; and 2) document patterns of beta diversity throughout the region in both open and forested habitat. I systematically sampled ants at 67 sites from May to August 2010, spanning 10 degrees of latitude, and 1000 meters of elevation. Patterns of alpha and beta diversity across the region and along environmental gradients differed between forested and open habitats. Local species richness was higher in the low elevation and warmest sites and was always higher in open habitat than in forest habitat transects. Richness decreased as temperature decreased or elevation increased. Forested transects show strong patterns of decreasing dissimilarity in species composition between sites along the temperature gradient but open habitat transects did not. Maximum temperature of the warmest month better predicted species richness than either latitude or elevation. I find that using environmental variables as key predictors of richness yields more biologically relevant results, and produces simpler macroecological models than commonly used models which use only latitude and elevation as predictors of richness and diversity patterns. This study contributes to the understanding of mechanisms that structure the communities of important terrestrial arthropods which are likely to be influenced by climatic change. [ABSTRACT FROM AUTHOR]

ABSTRACT The sustainability of ecosystem services depends on a firm understanding of both how organisms provide these services to humans and how these organisms will be altered with a changing climate. Unquestionably a dominant feature of most ecosystems, invertebrates affect many ecosystem services and are also highly responsive to climate change. However, there is still a basic lack of understanding of the direct and indirect paths by which invertebrates influence ecosystem services, as well as how climate change will affect those ecosystem services by altering invertebrate populations. This indicates a lack of communication and collaboration among scientists researching ecosystem services and climate change effects on invertebrates, and land managers and researchers from other disciplines, which becomes obvious when systematically reviewing the literature relevant to invertebrates, ecosystem services, and climate change. To address this issue, we review how invertebrates respond to climate change. We then review how invertebrates both positively and negatively influence ecosystem services. Lastly, we provide some critical future directions for research needs, and suggest ways in which managers, scientists and other researchers may collaborate to tackle the complex issue of sustaining invertebrate-mediated services under a changing climate. [ABSTRACT FROM AUTHOR]

What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51 ,388 ant abundance and occurrence records of more than 2,693 species and 7,953 morphospecies from local assemblages collected at 4,212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type, and degree of disturbance. The aim of compiling this data set was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardized methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing data set. [ABSTRACT FROM AUTHOR]

Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk. [ABSTRACT FROM AUTHOR]