Impact of needle age on the response of respiration in Scots pine to long-term elevation of carbon dioxide concentration and temperature

Sixteen 20-year-old Scots pine (Pinus sylvestris L.) trees growing in the field were enclosed in environment-controlled chambers that for 4 years maintained: (1) ambient conditions (CON); (2) elevated atmospheric carbon dioxide concentration [CO2] (ambient + 350 micromol mol-1; EC); (3) elevated temperature (ambient + 2-3 degrees C; ET); or (4) elevated [CO2] and temperature (EC+ET). Dark respiration rate, specific leaf area (SLA) and the concentrations of starch and soluble sugars in needles were measured in the fourth year. Respiration rates, on both an area and a mass basis, and SLA decreased in EC relative to CON, but increased in ET and EC+ET, regardless of needle age class. Starch and soluble sugar concentrations for a given needle age class increased in EC, but decreased slightly in ET and EC+ET. Respiration rates and SLA were highest in current-year needles in all treatments, whereas starch and soluble sugar concentrations were highest in 1-year-old needles. Relative to that of older needles, respiration of current-year needles was inhibited less by EC, but increased in response to ET and EC+ET. All treatments enhanced the difference in respiration between current-year and older needles relative to that in CON. Age had a greater effect on needle respiration than any of the treatments. There were no differences in carbohydrate concentration or SLA between needle age classes in response to any treatment. Relative to CON, the temperature coefficient (Q10) of respiration increased slightly in EC, regardless of age, but declined significantly in ET and EC+ET, indicating acclimation of respiration to temperature.     

Occurrence of antibodies to group specific chlamydia antigen in cattle in various areas of Finland.

The occurrence of group specific complement fixing antibodies was studied in 361 cattle sera from 36 herds in 6 areas in Finland. Sixty-two (17.2%) were positive. The antibody frequency increased significantly from the south to the north and the frequency was significantly higher in forest than in field pastures. The reasons for the differences are discussed. The tick, Ixodes ricinus, perhaps has no significant epidemiological role in chlamydial epidemiology in Finland.     

Effect of shading on leaf structure and photosynthesis in young birches, Betula pendula Roth. and B. pubescens Ehrh.

The canopy structure and within-stand light conditions of several young birch (Betula pendula Roth. and B. pubescens Ehrh.) stands were studied. In addition, 2-year-old silver birch seedlings were subjected to varying degrees of artificial shading for one growing season in order to interpret the results of the former experiments. The shading increased the specific leaf area and the thickness of leaf mesophyll was reduced by increased shading. Similarly, the maximum photosynthetic rate and the light intensity for photosynthetic saturation were decreased in shading. Both phenomena seemed to be associated with the increase in specific leaf area and the decrease in the amount of chlorophyll per unit of leaf area.     

Access to green areas and the frequency of visits – A case study in Helsinki

Environmental considerations concerning physical activity and health relate to accessibility, and this accessibility is directly influenced by how recreation areas and facilities are provided and managed. This study aims to provide some evidence to support the general argument that a good supply of recreation opportunities encourages people's participation in outdoor recreation. The study's data are compiled from an outdoor recreation survey of Finnish 15- to 74-year olds, conducted between 1998 and 2000, which focused on the recreational behaviour of people living in Helsinki (n=367), and their visits to close-to-home outdoor recreation areas. Almost all (97%) of the Helsinki residents surveyed participated in outdoor recreation during the year. Half of them embarked on a recreational outing daily or every other day. The most typical close-to-home activity was walking for pleasure or fitness. Other popular activities were cycling, jogging, dog walking and outings with children. Physical or fitness activities represented about 90% of all close-to-home outings. Those who lived in the suburbs of Helsinki participated in close-to-home recreation significantly more often than those living in the city centre, and had done so more recently in terms of when the survey was conducted. The amount of green areas in the vicinity of the participant's residence and the short distance to green areas suitable for recreational use increased the number of close-to-home outings among Helsinki residents. This supports the argument that a good provision of opportunities promotes an active lifestyle. Thus, recreation areas and facilities should be located close to residential areas, and provide safe, comfortable and year-round access for daily outings.     

Increased forest production through forest tree breeding

Forest tree breeding started in the middle of the twentieth century and since then the use of improved forest regeneration material has become an essential part of forestry in many countries. This review describes methods and achievements of tree breeding programmes, which aim at increasing the quantities and improving qualities of wood-based raw materials through selection, field testing and controlled crossings. Most improved materials currently deployed are seed crops from first-generation phenotypic or tested seed orchards, which offer 10–25% gains in yield depending on the selection intensity of parent trees. Methods of vegetative propagation are developed intensively so that it could be applied to a larger range of species, because it offers high genetic gain and uniformity of the material. Genomic tools are also developed to enhance the efficacy of selection. Applications of genetic engineering are currently limited to research purposes. Forest tree breeding will be an integral part of bioeconomy in securing the production of good quality raw materials in large quantities and will have a significant economic impact on the profitability of forestry in the long term.     

Modeling the effects of climate change and management on the dead wood dynamics in boreal forest plantations

The present research examines the joint effects of climate change and management on the dead wood dynamics of the main tree species of the Finnish boreal forests via a forest ecosystem simulator. Tree processes are analyzed in stands subject to multiple biotic and abiotic environmental factors. A special focus is on the implications for biodiversity conservation thereof. Our results predict that in boreal forests, climate change will speed up tree growth and accumulation ending up in a higher stock of dead wood available as habitat for forest-dwelling species, but the accumulation processes will be much smaller in the working landscape than in set-asides. Increased decomposition rates driven by climate change for silver birch and Norway spruce will likely reduce the time the dead wood stock is available for dead wood-associated species. While for silver birch, the decomposition rate will be further increased in set-aside in relation to stands under ordinary management, for Norway spruce, set-asides can counterbalance the enhanced decomposition rate due to climate change thereby permitting a longer persistence of different decay stages of dead wood.