The history of seabird colonies and the North Water ecosystem: Contributions from palaeoecological and archaeological evidence

The North Water (NOW) polynya is one of the most productive marine areas of the Arctic and an important breeding area for millions of seabirds. There is, however, little information on the dynamics of the polynya or the bird populations over the long term. Here, we used sediment archives from a lake and peat deposits along the Greenland coast of the NOW polynya to track long-term patterns in the dynamics of the seabird populations. Radiocarbon dates show that the thick-billed murre (Uria lomvia) and the common eider (Somateria mollissima) have been present for at least 5500 cal. years. The first recorded arrival of the little auk (Alle alle) was around 4400 cal. years bp at Annikitsoq, with arrival at Qeqertaq (Salve Ø) colony dated to 3600 cal. years bp. Concentrations of cadmium and phosphorus (both abundant in little auk guano) in the lake and peat cores suggest that there was a period of large variation in bird numbers between 2500 and 1500 cal. years bp. The little auk arrival times show a strong accord with past periods of colder climate and with some aspects of human settlement in the area.     

Perceived Mental Stress and Reactions in Heart Rate Variability—A Pilot Study Among Employees of an Electronics Company

In this study perceived mental stress during occupational work was compared to heart rate variability (HRV) using a traditional questionnaire and a novel wristop heart rate monitor with related software. The aim was to find HRV parameters useful for mental stress detection. We found the highest correlation between perceived mental stress with the differences between the values of triangular interpolation of rythm-to-rythm (RR) interval histogram (TINN) and the root mean square of differences of successive RR intervals (RMSSD) obtained in the morning and during the workday(r = -.73 andr = -.60, respectively). The analysis shows that as the RMSSD and TINN value differences increase from night to morning, the stress decreases.     

Heavy metal solubility in podzolic soils exposed to the alkalizing effect of air pollutants

The heavy metal content of pine forest soil was studied near the boundary between Russia and Estonia, an area characterized by large amounts of acidic and basic air pollutants, mainly sulfur dioxide and calcium. Alkalization dominates the processes in soil, since sulfur is adsorbed only in small quantities, and calcium is much better adsorbed. In addition to Ca, great amounts of Al, Fe, K, and Mg are accumulated in the humus layer due to air pollution. The heavy metal content has increased. The exchangeable content of heavy metals was in many cases much higher in polluted alkaline soils than in non-polluted acidic soils, even the ratio of exchangeable to total metal content being higher in alkaline plots. To avoid a dangerous increase in soluble heavy metal content, it is important to decrease not only the large sulfur emissions of local pollutant sources, but also the alkaline pollutants. A similar concern must be taken into account when liming of acidic forest soils is planned.     

Ecological condition of forests around the eastern part of the Gulf of Finland

The effects of air pollutants on forests around the eastern part of the Gulf of Finland were studied by measurement of the sulphur and calcium content of pine needles and evaluation of the ecological conditions of pine forests. Several parameters for pine trees and their needles were chosen as well as the species composition and condition of epiphytic lichens. Very high pine needle S- and Ca-contents were measured in the vicinity of the Narva and Slantsy plants. In this region both the acid and basic pollutant load is massive, partly neutralizing each other. It is suggested that the total load will, sooner or later, cause unexpected environmental damage. Wide 'lichen desert' areas were detected around Narva and Slantsy. Near the margins of these areas extraordinary epiphytes on pines were observed namely Xanthoria parietina (L.) Th.Fr. and red-coloured green alga Trentepohlia umbrina. They are regarded as indicators of alkaline pollution. The lowest pine needle S- and Ca-contents of the study area were measured in south-eastern Finland. The condition of pine forests and their needles was, however, better on the neighbouring Karelian Isthmus although the species number of epiphytic lichens was very low and the condition of the lichens was poor. It is suggested that these most sensitive indicators of air pollutants are damaged by pollutants from St Petersburg and Narva. Vast virgin forests of the Karelian Isthmus act as pollutant sinks reducing the effect of pollutants on trees. On the Finnish side intensive forest management has been carried on for many decades making forests and trees more sensitive to pollutants.     

The effects of simultaneous large acidic and alkaline airborne pollutants on forest soil

The effects of air pollutants on soil were studied in Scots pine (Pinus sylvestris L.) forests near the boundary of Russia and Estonia. The study area is characterized by large amounts of acidic and basic pollutants, mainly sulphur dioxide (SO(2)) and calcium (Ca). Several variables were measured in different horizons of the podzolic soil polluted by emissions from local sources in areas of several thousands of square kilometers. Alkalinization dominates the processes in the soil, since sulphur is absorbed only in small quantities and Ca is much better absorbed. Ca content in humus horizon may rise even to 100 000 mg kg(-1) and the pH of originally very acidic soil may rise to 8.3. Total aluminum (Al) content was high in the heavily polluted plots, since emissions contain much Al. On the other hand, the exchangeable Al was very low in these alkaline sites. A larger quantity of exchangeable Al occurred farther from the pollutant sources, even though total Al in these plots was low. These plots had acidic soils in which Al is in exchangeable form. Due to the neutralizing effect of acidic and basic pollutants, forest damage in the study area was not as serious as might be supposed. Complicated pollutant situations must be taken into consideration when pollution-caused environmental protection measures are planned. It is not reasonable to reduce only SO(2) emissions, but necessary to lower the basic emissions at the same time.     

Triclosan,a commonly used bactericide found in human milk and in the aquatic environment in Sweden

High levels of the commonly used, effective bactericide Triclosan was found in three out of five randomly selected human milk samples. It was also found in the bile of fish exposed to municipal wastewater and in wild living fish from the receiving waters of the three wastewater treatment plants.     

Immune function, dominance and mating success in drumming male wolf spiders Hygrolycosa rubrofasciata

In this study, we provide a piece of experimental evidence that immune function is related to dominance and mating success in wild caught male wolf spiders, Hygrolycosa rubrofasciata. In the mating season, H. rubrofasciata males are actively searching for receptive females, and while searching males often engage in agonistic behavior (i.e., agonistic drumming signals, chases, and fights) with each other. The present results demonstrate that dominant males had higher lytic activities in their hemolymph than subordinates. Lytic activity estimates the concentration of antimicrobial peptides with lysozyme-like activity in hemolymph, which have been shown to play an important role in defense against bacteria, viruses, and fungi. Dominants also had higher courtship drumming rates than subordinates. Moreover, winners in mating competition had higher lytic activities than losers, but this was measured nonindependently of dominance status. Among males with mating failure, there was a moderate negative correlation between encapsulation rate and courtship drumming rate, suggesting that low quality males might not be able to bear the immunological costs of courtship behavior. These results suggest that females might gain immunological benefits by preferring vigorous males.     

Invertebrates and Boreal Forest Management

Logging has ecological effects on invertebrates in Fennoscandian boreal forest. Especially affected are species associated with micro-habitats of natural old-growth forest, such as coarse woody debris, large deciduous trees, and patches of wet swamp-forest. Furthermore, the effective control of forest fires has adversely affected many species that require burned substrates. Although old-growth specialists tend to disappear from clear-cuts, local invertebrate species richness (α-diversity) may increase as forest generalists persist and numerous open-habitat species appear. This seems true at least for taxa (e.g., ground-beetles and spiders) that are not directly associated with the characteristic micro-habitats of old growth mentioned above. However, at the landscape or biogeographical scale intensive logging tends to homogenize forest habitats and lead to declines of sensitive species. Based on these findings three complementary approaches appear useful for the maintenance of boreal biodiversity while harvesting timber. (1) Undisturbed old-growth forests must be set aside to sustain specialist species and to serve as sources for recolonization. (2) Because these reserves are not, and will probably not be, large and regionally representative enough, ecologically sound silvicultural practices must be developed using natural disturbance regimes as guidelines. (3) Restoration of habitats and the process of natural regeneration through fire is imperative for the recovery of associated species assemblages. However, the process of recovery presupposes that colonists are available, which may not always be the case.     

A method for facilitating the use of algae growing on tree trunks as bioindicators of air quality

The abundance of epiphytic green algae has been observed to correlate strongly with air quality in several studies. In contrast to lichens, the abundance of green algae is difficult to measure accurately by visual observation. A new method based on photography and digital image processing was developed to estimate the chlorophyll content of algae growing on the bark of pine. Calibration data for the method was collected from polluted areas by spectrophotometric analysis of chlorophyll density.     

On the functional extinction of the Passenger Pigeon

The Passenger Pigeon (Ectopistes migratorius) was a social breeder, and it has been suggested that the species experienced functional extinction, defined as a total reproductive failure, prior to its actual extinction in the early years of the 20th century. We applied a novel randomization test based on the relative times of the most recent egg‐ and skin‐specimen sightings (i.e., recorded date of specimen collection) to test for functional extinction. For a total of 6 eggs and 27 skins, the observed significance level was 0.38, which indicated that the species did not become functionally extinct. Thus, proposals to reverse its rapid decline in the late 19th century could have been successful.