Seasonal polydomy and unicoloniality in a polygynous population of the red wood ant Formica truncorum

Ant colonies may have a single or several reproductive queens (monogyny and polygyny, respectively). In polygynous colonies, colony reproduction may occur by budding, forming multinest, polydomous colonies. In most cases, budding leads to strong genetic structuring within populations, and positive relatedness among nestmates. However, in a few cases, polydomous populations may be unicolonial, with no structuring and intra-nest relatedness approaching zero. We investigated the spatial organisation and genetic structure of a polygynous, polydomous population of Formica truncorum in Finland. F. truncorum shifts nest sites between hibernation and the reproductive season, which raises the following question: are colonies maintained as genetic entities throughout the seasons, or is the population unicolonial throughout the season? Using nest-specific marking and five microsatellite loci, we found a high degree of mixing between individuals of the population, and no evidence for a biologically significant genetic structuring. The nestmate relatedness was also indistinguishable from zero. Taken together, the results show that the population is unicolonial. In addition, we found that the population has undergone a recent bottleneck, suggesting that the entire population may have been founded by a very limited number of females. The precise causes for unicoloniality in this species remain open, but we discuss the potential influence of intra-specific competition, disintegration of recognition cues and the particular hibernation habits of this species.     

Are Bavarian Forests (southern Germany) at risk from ground-level ozone? Assessment using exposure and flux based ozone indices

Exposure and flux-based indices of O₃ risk were compared, at 19 forest locations across Bavaria in southern Germany from 2002 to 2005; leaf symptoms on mature beech trees found at these locations were also examined for O₃ injury. O₃ flux modelling was performed using continuously recorded O₃ concentrations in combination with meteorological and soil moisture data collected from Level II forest sites. O₃ measurements at nearby rural open-field sites proved appropriate as surrogates in cases where O₃ data were lacking at forest sites (with altitude-dependent average differences of about 10% between O₃ concentrations). Operational thresholds of biomass loss for both O₃ indices were exceeded at the majority of the forest locations, suggesting similar risk under long-term average climate conditions. However, exposure-based indices estimated higher O₃ risk during dry years as compared to the flux-based approach. In comparison, minor O₃-like leaf injury symptoms were detected only at a few of the forest sites investigated. Relationships between flux-based risk thresholds and tree response need to be established for mature forest stands for validation of predicted growth reductions under the prevailing O₃ regimes.     

The population biology of the living coelacanth studied over 21 years

Between 1986 and 2009 nine submersible and remote-operated vehicle expeditions were carried out to study the population biology of the coelacanth Latimeria chalumnae in the Comoro Islands, located in the western Indian Ocean. Latimeria live in large overlapping home ranges that can be occupied for as long as 21 years. Most individuals are confined to relatively small home ranges, resting in the same caves during the day. One hundred and forty five coelacanths are individually known, and we estimate the total population size of Grande Comore as approximately 300–400 adult individuals. The local population inhabiting a census area along an 8-km section of coastline remained stable for at least 18 years. Using LASER-assisted observations, we recorded length frequencies between 100 and 200 cm total length and did not encounter smaller-bodied individuals (<100 cm total length). It appears that coelacanth recruitment in the observation areas occur mainly by immigrating adults. We estimate that the mean numbers of deaths and newcomers are 3–4 individuals per year, suggesting that longevity may exceed 100 years. The domestic fishery represents a threat to the long-term survival of coelacanths in the study area. Recent changes in the local fishery include a decrease in the abundance of the un-motorized canoes associated with exploitation of coelacanths and an increase in motorized canoes. Exploitation rates have fallen in recent years, and by 2000, had fallen to lowest ever reported. Finally, future fishery developments are discussed.     

Influence of altitude concerning the contamination of humus soils in the German Alps: a data evaluation approach using PyHasse

Background, aim and scope  

In an international project named MONARPOP (Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants), selected chemicals in different environmental media were analysed in the years 2004 and 2005. Seventeen pesticides were chosen and analysed in humus and mineral soil in the German Alps. The samples were taken at different altitudes.     

MOC scoping—Ensuring that MOC action items are correctly and completely described

Shortly after initiating a Management of Change instance, the owner develops a list of action items that need to be accomplished in order to successfully complete the MOC. This activity is termed “scoping the MOC”. A well-scoped MOC is efficient and lower risk; a poorly-scoped MOC is inefficient and higher risk.The quality of MOC scoping depends largely on the methodology used, with different sites using anything from no scoping at all, guesswork approaches, checklist approaches, to very sophisticated asset-based scoping.This paper reviews the various scoping methodologies using examples from actual MOC processes currently in use at chemical plants and refineries. The scoping techniques are then evaluated in terms of cost and error susceptibility of the resulting MOCs, using quantitative assessment tools. The results of this research provide specific guidelines on how to optimize scoping for small, medium and large MOCs.