The role of chemical information in shaping the spatial activity of bank voles in a free-living population

A field experiment was carried out in two types of forest environment — a relatively homogenous mixed coniferous forest with low plant species diversity and a reach and spatially differentiated alder wood. Spatial variation in activity of voles was sampled by placing ink pads and paper inside PVC waterpipes laid in a line on the forest floor. In the first stage of the experiment, use of space by bank volesClethrionomys glareolus (Schreber, 1780) was analysed without any bait in track collection tubes. In the second stage, we used an attractant in the form of scent collected from alien bank vole individuals of different sex (males, females), age (juveniles, adults) and physiological state (sexually active and not active). In the coniferous forest the distribution of number of visits in tracking tubes was of aggregated character both before and after providing odour of alien individuals. In the alder wood the aggregation level that had been initially lower than in the coniferous forest increased after providing scent. As a consequence, placing scent of alien individuals resulted in decreasing differences in animal distribution in both habitats. The results allow also to the supposition that the reaction to scent depends on sex, age, and the physiological state of the donor.     

Gram-negative bacteria associated with timber as a potential respiratory hazard for woodworkers

The concentration and species composition of viableGram-negative bacteria was determined in samples of coniferous wood (Scots pine) and deciduous wood (European beech), and in air samples taken during the processing of these woods in sawmills. The concentration of Gram-negative bacteria in the sapwood of pine logs ranged from 1.0 × 10¹ to 6.2 × 10⁴ CFU/g. Their concentration in the air of the pine processing sawmill was within a range of 1.0 × 10²–6.3 × 10² CFU/m³. Concentration of Gram-negative bacteria in the sapwood of beech logs was similar to that in the sapwood of pine logs, ranging from 1.0 × 10¹ to 4.6 × 10⁴ CFU/g. However, the concentration of these bacteria in the air of a beech processing sawmill was within a range of 7.8 × 10³–1.3 × 10⁴ CFU/m³, being significantly higher than in a pine processing sawmill. Enterobacteriaceae strains, mostly Enterobacter spp. and Rahnella spp., made up 70–75% of Gram-negative bacteria isolated from pine and beech wood and from the air pollutedwith sawdust from these woods. The aerial exposure to Gram-negative bacteria possessing endotoxic andallergenic properties poses potential risk ofoccupational respiratory disorders among sawmillworkers, in particular those processing beech wood.