Globally invariant metabolism but density-diversity mismatch in springtails.

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning

Global fine-resolution data on springtail abundance and community structure

Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.</p

Demographic drivers of Norway rat populations from urban slums in Brazil

The Norway rat is a globally distributed pest, known for its resilience to eradication and control programs. Efficient population control, especially in urban settings, is dependent on knowledge of rat demography and population ecology. We analyzed the relationship between four demographic outcomes, estimated by live-trapping data, and fine-scale environmental features measured at the capture site. Wounds, a proxy for agonistic interactions, were associated with mature individuals. Areas with environmental features favorable to rats, such as open sewers and unpaved earth, were associated with more mature individuals with a better body condition index. The control measures (environmental stressors) are likely to be disrupting the social structure of rat colonies, increasing the frequency and distribution of agonistic interactions, which were common in both sexes and maturity states. The relationship between the favorable environmental conditions and the demographic markers analyzed indicate possible targets for infestation control through environmental manipulation, and could be incorporated into current pest management programs to achieve long-term success. Our study indicate that urban interventions focused on removal of potential resources for rats could be potential long-term solutions by reducing the carrying capacity of the environment

Dataset used in the assessment of the article "Basic urban services fail to neutralise environmental determinants of 'rattiness', a composite metric of rat abundance"

This data was collected in four Brazilian informal settlements located in the city of Salvador - the third largest city of Brazil - in the wet season of the year 2018. The data includes the collection of three rat abundance metrics - namely, rat marks on track plates, rats caught in live traps and removed, and presence of rat signs (faecal droppings, trails and active burrows) - in a total of 529 independent sampling locations. In addition to the single rat metrics, which were also used to compose the rattiness outcome, the data contain the baseline environmental and socioeconomic (surveyed and mapped) variables and the BUS variables considered in Carvalho-Pereira et al., 2023

Basic urban services fail to neutralise environmental determinants of ‘rattiness’, a composite metric of rat abundance

Globally, low-income urban communities suffer from poor provision of services and degraded environments, favouring opportunistic zoonotic reservoirs, such as rats. Large-scale infrastructural improvements in these contexts are limited, but targeted control of disease reservoirs has sometimes been achieved. A starting point for the targeted control of rats is assessing the impact of existing basic services on rat abundance. However, there is no gold-standard metric for rat abundance, and studies have used different or multiple metrics. Here, therefore, in four low-income urban Brazilian communities, we address the question of whether basic urban services (BUS) – trash collection, rodenticide application and health community agent visits – affect rat abundance, through the first application of the rattiness modelling framework. This recently-developed geostatistical method combines multiple abundance metrics (here, three) to generate rattiness, a proxy for rat abundance, a spatially-continuous latent process common to all metrics. In a cross-sectional study, we exploited spatial heterogeneities in BUS to evaluate its association with the presence of rat signs, rat marks on track plates, and live-trapped rats, and with rattiness, which combined these three imperfect metrics. Rattiness proved to be a useful tool for pooling information among the three metrics and was associated with a greater range of baseline predictors than any single metric. Rat signs and rattiness were positively associated with higher levels of BUS provision and environmental variables known to provide resources for rats. The strong association of baseline environmental variables with rat abundance highlights the need for targeted, small-scale environmental modifications to reduce resources for rats