Tourist species bias estimates of extrapolated species density in dispersive taxa: a case study from a litter beetle assemblage in temperate woodland

Extrapolative nonparametric estimators of species density are commonly used in community ecology. However, they are dependent on either (1) their use on non-dispersive taxa, or (2) the ability to separate tourists from residents in dispersive taxa. We undertook ten years of leaf litter sampling in an ancient woodland in the New Forest, Southern England. We identi- fied all the beetles from those samples and assigned them a residency status (residents, stratum tourists, and habitat tourists). Extrapolations, using the Chao 2, first- and second-order jackknife, and bootstrap approaches, of all sampled beetles all showed large overestimates of species richness when compared with extrapolations based on just residents. We recommend that the estimators should be used with caution as estimates of actual species density for dispersive taxa unless the natural history of most species in a community is well known. This applies especially to tropical ecosystems where many species have not been described. This reinforces the need for more descriptive natural history

Land use and soil characteristics affect soil organisms differently from above-ground assemblages

Background: Land-use is a major driver of changes in biodiversity worldwide, but studies have overwhelmingly focused on above-ground taxa: the effects on soil biodiversity are less well known, despite the importance of soil organisms in ecosystem functioning. We modelled data from a global biodiversity database to compare how the abundance of soil-dwelling and above-ground organisms responded to land use and soil properties. Results: We found that land use affects overall abundance differently in soil and above-ground assemblages. The abundance of soil organisms was markedly lower in cropland and plantation habitats than in primary vegetation and pasture. Soil properties influenced the abundance of soil biota in ways that differed among land uses, suggesting they shape both abundance and its response to land use. Conclusions: Our results caution against assuming models or indicators derived from above-ground data can apply to soil assemblages and highlight the potential value of incorporating soil properties into biodiversity models.Natural Environment Research Council (NERC): NE/L002515/1 and NE/M014533/1. European Union funding: 81794

Temporal and spatial variation in soil macrofauna of UK woodlands

Little is known of the ecological structure of macro-invertebrate assemblages that live in the soil and leaf litter of British woodlands. This is the first study to investigate these assemblages at the whole community level, examining them at a range of resolutions from higher taxonomic unit (HTU) to species-level diversity and abundance across seven major groups including beetles, spiders and earthworms. Using the National Vegetation Classification (NVC) as a framework, 17 different wet and dry woodland types were sampled across England to examine the macro-invertebrate soil and litter communities, to compare and contrast the range of functional roles in each case, and to uncover the complex vegetational and environmental factors that influence invertebrate assemblage composition and structure. As the most widespread and invertebrate diverse woodland in the UK, an additional ten oak woodlands were sampled to explore the influence of geographic and climatic variables upon the patterns of soil/litter macro-invertebrates. The key findings suggest that soil moisture is most influential in determining the invertebrate species composition in all woodland types, indicating the wet woodlands are not only different to each other but to all other woodlands, and that the dry woodlands are more similar. Geographic location and soil type were found to have most influence on the diversity and abundance of both plant and invertebrate species in the dry woodlands. Air temperature is a key environmental influence on the oak woodlands as they can be grouped by geographic area, namely northern, western and central England localities. An oak woodland was further investigated for temporal patterns of soil invertebrates over a 12-month period. Findings indicate that most invertebrate species and functional groups peak in abundance at two key periods during the year: spring/early summer and later summer/autumn, this coincides with food availability for these groups at these times.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

CXCL1/KC and CXCL2/MIP-2 Are Critical Effectors and Potential Targets for Therapy of Escherichia coli O157:H7-Associated Renal Inflammation

Neutrophilia is a characteristic of hemolytic uremic syndrome caused by Shiga toxin (Stx2)-producing Escherichia coli. However, the role of neutrophils in the toxin-induced renal injury occurring in enterohemorrhagic E. coli infection remains undefined. We report the trafficking of neutrophils to the kidney of C57BL/6 mice throughout a 72-hour time course after challenge with purified E. coli Stx2 and lipopolysaccharide (LPS). Increased neutrophils were observed in the renal cortex, particularly within the glomeruli where a more than fourfold increase in neutrophils was noted within 2 hours after challenge. Using microarray analysis, an increased number of transcripts for chemoattractants CXCL1/KC (69-fold at 2 hours) and CXCL2/MIP-2 (29-fold at 2 hours) were detected. Ribonuclease protection assays, Northern blotting, enzyme-linked immunosorbent assay, and immunohistochemistry confirmed microarray results, showing that both chemokines were expressed only on the immediate periglomerular epithelium and that these events coincided with neutrophil invasion of glomeruli. Co-administration of Stx2 with LPS enhanced and prolonged the KC and MIP-2 host response (RNA and protein) induced by LPS alone. Immunoneutralization in vivo of CXCL1/KC and CXCL2/MIP-2 abrogated neutrophil migration into glomeruli by 85%. These data define the molecular basis for neutrophil migration into the kidney after exposure to virulence factors of Shiga toxin-producing E. coli O157:H7

A cross-continental comparison of assemblages of seed- and fruit-feeding insects in tropical rain forests: faunal composition and rates of attack

Aim Insects feeding on seeds and fruits represent interesting study systems, potentially able to lower the fitness of their host plants. In addition to true seed eaters, a suite of insects feed on the fleshy parts of fruits. We examined the likelihood of community convergence in whole insect assemblages attacking seeds/fruits in three tropical rain forests. Location Three ForestGEO permanent forest plots within different biogeographical regions: Barro Colorado Island (Panama), Khao Chong (Thailand) and Wanang (Papua New Guinea). Methods We surveyed 1,186 plant species and reared 1.1 ton of seeds/fruits that yielded 80,600 insects representing at least 1,678 species. We assigned seeds/fruits to predation syndromes on the basis of plant traits relevant to insects, seed/fruit appearance and mesocarp thickness. Results We observed large differences in insect faunal composition, species richness and guild structure between our three study sites. We hypothesize that the high species richness of insect feeding on seeds/fruits in Panama may result from a conjunction of low plant species richness and high availability of dry fruits. Insect assemblages were weakly influenced by seed predation syndromes, both at the local and regional scale, and the effect of host phylogeny varied also among sites. At the driest site (Panama), the probability of seeds of a plant species being attacked depended more on seed availability than on the measured seed traits of that plant species. However, when seeds were attacked, plant traits shaping insect assemblages were difficult to identify and not related to seed availability. Main conclusions We observed only weak evidence of community convergence at the intercontinental scale among these assemblages. Our study suggests that seed eaters may be most commonly associated with dry fruits at relatively dry tropical sites where fleshy fruits may be less prevalent