The influence of eating psychopathology on autobiographical memory specificity and social problem-solving

The primary aim was to examine to influence of subclinical disordered eating on autobiographical memory specificity (AMS) and social problem solving (SPS). A further aim was to establish if AMS mediated the relationship between eating psychopathology and SPS. A non-clinical sample of 52 females completed the autobiographical memory test (AMT), where they were asked to retrieve specific memories of events from their past in response to cue words, and the means-end problem-solving task (MEPS), where they were asked to generate means of solving a series of social problems. Participants also completed the Eating Disorders Inventory (EDI) and Hospital Anxiety and Depression Scale. After controlling for mood, high scores on the EDI subscales, particularly Drive-for-Thinness, were associated with the retrieval of fewer specific and a greater proportion of categorical memories on the AMT and with the generation of fewer and less effective means on the MEPS. Memory specificity fully mediated the relationship between eating psychopathology and SPS. These findings have implications for individuals exhibiting high levels of disordered eating, as poor AMS and SPS are likely to impact negatively on their psychological wellbeing and everyday social functioning and could represent a risk factor for the development of clinically significant eating disorders

Counting ants (Hymenoptera: Formicidae): Biodiversity sampling and statistical analysis for myrmecologists

Biodiversity sampling is labor intensive and is especially challenging for myrmecologists, because the sampling units (individual workers) do not correspond in a simple way to the natural units of diversity (individual nests). Because it is usually not possible to reach a sampling asymptote for ants, comparisons of species richness among collections have to be carefully standardized for the number of individuals and number of samples examined. Asymptotic estimators allow for extrapolation to an estimated asymptote of species richness, and rarefaction curves permit meaningful comparisons of samples by interpolating data to a standardized number of sampling units. Winkler sacks of leaf litter and specialized traps for arboreal ants often yield distinctive sets of species in tropical and subtropical latitudes. These microhabitats are best treated as distinctive assemblages that can be compared with stratified sampling. Within other habitat types, different baiting and sampling methods yield similar, but not identical sets of species, and many authors have advocated using a diversity of methods to gain the greatest coverage of species. However, many of the distinctive species that are sampled by a particular method are rare, and are just as likely to have been found with other sampling methods. The estimated similarity in composition of ants sampled by different methods in the same habitat is probably greater than has been appreciated. Recent published comparisons of sampling efficiency have shown that hand collecting accumulates species more efficiently than the more commonly used pitfall traps or baits. However, if hand-collected samples are to be analyzed quantitatively, hand sampling must be standardized to a constant plot size that is searched for a fixed amount of time, and all nests encountered must be sampled and counted. For comparative studies of ant assemblages across habitats, hand collecting may be superior to either litter sampling or pitfall traps because it can be used in sites that have no leaf litter or are too environmentally sensitive, too rocky, too steep, or contain too much human and domestic animal traffic for pitfall trapping. Data from hand sampling and grids of pitfall traps lend themselves to slightly different kinds of analyses. Hand sampling probably gives the best estimates of the true frequency of nests of different species in an area, and the data can be used with individual-based rarefaction curves and many standard parametric statistical tests. Data from pitfalltrap grids should usually be treated as sample-based occurrences, and analyzed with sample-based rarefaction and diversity estimators. For the purposes of estimating diversity, myrmecologists should avoid the temptation to analyze the underlying counts of individual workers. Data from replicated grids of pitfall traps can be analyzed with hierarchical occupancy models. These newly developed models provide useful estimates of probabilities of occurrence and probabilities of detection for each species in the assemblage. Biogeographic patterns of ant diversity, such as latitudinal gradients of species richness, are comparable to those seen in other taxa, and the data collected by myrmecologists can contribute in important ways to our general understanding of biodiversity patterns

The effects of insects, nutrients, and plant invasion on community structure and function above- and belowground

Soil nutrient availability, invasive plants, and insect presence can directly alter ecosystem structure and function, but less is known about how these factors may interact. In this 6-year study in an old-field ecosystem, we manipulated insect abundance (reduced and control), the propagule pressure of an invasive nitrogen-fixing plant (propagules added and control), and soil nutrient availability (nitrogen added, nitrogen reduced and control) in a fully crossed, completely randomized plot design. We found that nutrient amendment and, occasionally, insect abundance interacted with the propagule pressure of an invasive plant to alter above- and belowground structure and function at our site. Not surprisingly, nutrient amendment had a direct effect on aboveground biomass and soil nutrient mineralization. The introduction of invasive nitrogen-fixing plant propagules interacted with nutrient amendment and insect presence to alter soil bacterial abundance and the activity of the microbial community. While the larger-scale, longer-term bulk measurements such as biomass production and nutrient mineralization responded to the direct effects of our treatments, the shorter-term and dynamic microbial communities tended to respond to interactions among our treatments. Our results indicate that soil nutrients, invasive plants, and insect herbivores determine both above- and belowground responses, but whether such effects are independent versus interdependent varies with scale

Monitoring the influx of new species through citizen science:the first introduced ant in Denmark

Climate change and invasive species threaten biodiversity, yet rigorous monitoring of their impact can be costly. Citizen science is increasingly used as a tool for monitoring exotic species, because citizens are geographically and temporally dispersed, whereas scientists tend to cluster in museums and at universities. Here we report on the establishment of the first exotic ant taxon (Tetramorium immigrans) in Denmark, which was discovered by children participating in The Ant Hunt. The Ant Hunt is a citizen science project for children that we ran in 2017 and 2018, with a pilot study in 2015. T. immigrans was discovered in the Botanical Garden of the Natural History Museum of Denmark in 2015 and confirmed as established in 2018. This finding extends the northern range boundary of T. immigrans by almost 460 km. Using climatic niche modelling, we compared the climatic niche of T. immigrans in Europe with that of T. caespitum based on confirmed observations from 2006 to 2019. T. immigrans and T. caespitum had a 13% niche overlap, with T. immigrans showing stronger occurrence in warmer and drier areas compared to T. caespitum. Mapping the environmental niches onto geographic space identified several, currently uninhabited, areas as climatically suitable for the establishment of T. immigrans. Tetramorium immigrans was sampled almost three times as often in areas with artificial surfaces compared to T. caespitum, suggesting that T. immigrans may not be native to all of Europe and is being accidentally introduced by humans. Overall, citizen scientists collected data on ants closer to cities and harbours than scientists did and had a stronger bias towards areas of human disturbance. This increased sampling effort in areas of likely introduction of exotic species naturally increases the likelihood of discovering species sooner, making citizen science an excellent tool for exotic species monitoring, as long as trained scientists are involved in the identification process

Response of macroarthropod assemblages to the loss of hemlock (Tsuga canadensis), a foundation species

In eastern North American forests, eastern hemlock (Tsuga canadensis) is a foundation species. As hemlock is lost from forests due to the invasive hemlock woolly adelgid (Adelges tsugae) and preemptive salvage logging, the structure of assemblages of species associated with hemlock is expected to change. We manipulated hemlock canopy structure at hectare scales to investigate the effects of hemlock death on assemblages of ants, beetles, and spiders in a New England forest. Relative to reference hemlock stands, both in situ death of hemlock and logging and removal of hemlock altered composition and diversity of beetles and spiders, and logging increased the species richness and evenness of ant assemblages. Species composition of ant assemblages in disturbed habitats was non-random relative to the regional species pool, but we found no evidence that interspecific competition shaped the structure of ant, beetle, or spider assemblages, in either manipulated or intact forest stands. Environmental filtering by hemlock appears to maintain low levels of species richness and evenness in forest stands, suggesting that the loss of hemlock due to the hemlock woolly adelgid or human activities will not likely lead to extirpations of ant, beetle, or spider species at local scales