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Abstract Recycling of construction and demolition waste (CDW) which contains materials with high resource value such as plastics, metals, wood, glass and concrete has been investigated in recent years due to tightening environmental legislation. Wood-plastic composites as an environmentally friendly material provide a possibility to enhance the recycling of material. The effect of the addition of CDW on the mechanical and moisture properties of WPC is studied in this paper. Three types of wood-plastic composites were manufactured with different amounts and composition of a CDW filler. Their properties were compared to the reference composite manufactured with virgin wood fibers and polypropylene as the polymer. It was found that the addition of the CDW filler weakened the mechanical properties of the composite generally, except for the fact that the Charpy impact strength was improved significantly. Minor variations in the composition of the CDW filler did not have an impact on the mechanical properties, but an increase in the amount of filler increased the deterioration of mechanical properties. For moisture properties, the addition of the CDW filler decreased the water absorption and thickness swelling of the composites. An increase in the filler content improved the thickness swelling more significantly than water absorption. [ABSTRACT FROM AUTHOR]

Abstract: Outdoor applications of composites raised questions about their durability. In this study, the effects of outdoor weathering on the properties of wood-polypropylene composites with and without pigments were examined. The composites were placed outdoors for one year, and their colour changes were evaluated after 1, 3, 6, 9 and 12 months of weathering. The weathering resulted in considerable colour fading of the composites. Composites containing darker colour pigments had better colour stability. Scanning electron microscopy analysis revealed that surface cracks caused by weathering in a wood-polypropylene composite having a higher polypropylene content were less abundant, and the deterioration of the surface layer was lower compared to composites containing less polymer. Measurements of melting temperatures by differential scanning calorimetry gave a consistent picture of polypropylene degradation in the surface layer. After weathering, a decrease in Charpy impact strength was found for composites characterised by higher moisture absorption. [Copyright &y& Elsevier]

Lichen phenolics that are known to leach out from lichen thalli during rainfall episodes are considered to be allelopathic or antimicrobial agents. On the other hand, small organic molecules originating from aboveground vegetation generally constitute an important C source for the soil microbial community. We studied the effects of leaching lichen acids on soil microbial processes by chemically removing usnic (UA) and perlatolic acid (PA) from the extracellular space of mat-forming lichen, Cladina stellaris, a dominant component of the ground vegetation in boreal oligotrophic forests. Removal of UA and PA did not affect the intracellular contents of the lichen. We hypothesized that if lichen acids have an adverse effect on soil biota, microbial respiration would increase underneath chemically manipulated lichen mats. In turn, if these substances provide energy source for the microorganisms, microbial respiration would decline under lichens from which PA and UA has been removed. Microbial metabolic activity, qCO2 was significantly lower under the lichens from which UA and PA had been removed, thus supporting the latter hypothesis. Removing UA and PA did not affect the amount of microbial C, N and P, or soil nutrient concentrations. Our results suggest that the microbial community in the soil under a lichen carpet is adapted to the presence of these lichen secondary metabolites and can utilize them as a C source. The approach of removing lichen substances from the system could be used as an effective research tool as it can overcome several problems that are often common in the studies on allelopathic interactions. [Copyright &y& Elsevier]

• The westernmost population of Eurasian species Rubus humulifolius became extinct in the wild in Finland in 1957. • Five ramets of R. humulifolius were rescued only hours before their habitat was destroyed. • R. humulifolius survived decades in ex situ conservation in a private garden. • R. humulifolius was micropropagated and reintroduced to a new site in 1988. • This was the first time that micropropagation was used to save an extirpated species. Rubus humulifolius is a Eurasian species that has got wide geographic distribution from western parts of Russia to Manchuria. The westernmost and separate population of R. humulifolius was found in Central Finland in 1917. The population was assumed to be formed via anthropogenic dispersal either in early nineteenth or early eighteenth century. In 20's the population was regarded as viable as it covered an area of a hectare almost as a monoculture in the field layer and it was protected by law in 1933. However, the state of the population started to decline in the same year as the area was ditched. In 1957 there were only fifteen rosettes left and five rosettes of were transplanted from the site to a private cottage garden just before the whole area was turned into a construction area and remaining population destroyed. The rescued population thrived but attempts to reintroduce plants from it to other sites considered to be suitable for the species were unsuccessful. Therefore, a research project initiated in 1986 for finding a suitable in vitro method for vegetative propagation of the plant. Eventually, the right formula for a substrate was found and 1500 new plants were produced in a couple of months. Now the in vitro propagated descendants of the five rescued ramets grow in several Finnish botanic gardens as part of their living collections and they also have been reintroduced to a natural site close to the original one in Central Finland. One can assume that a plant population that has gone through two bottlenecks – i.e. establishment of new population by presumably few long-distance dispersed genetic individuals and population decline to near extirpation – has got very narrow genetic diversity. Whether this is the case and whether inbreeding depression could explain e.g. the observed poor seed production in the population remains as a challenge for future research. Owing to ex situ conservation and in vitro technique applied for the first time to reintroduce an endangered species R. humulifolius is no more in immediate danger of extirpation. However, it is still classified as Critically Endangered (CR) as there is still only one population in the wild and it may be genetically depauperate. [ABSTRACT FROM AUTHOR]

The shores of the Bothnian Bay in the northern Baltic Sea are characterised by relatively rapid isostatic land uplift (ca. 6.9mmyear−1) continuously exposing virgin land for plants to colonise. Autogenic and allogenic changes in soil and plant communities will eventually make these exposed sites unsuitable for the early colonisers. The course of the primary succession in the waterfront is often delayed and shaped by frequent disturbances by ice scouring, water level movements and suffocation of extant vegetation by floating plant debris. Hence, we hypothesise that disturbances are the key processes underlying the local short-term dynamics of the plant populations of the seashore meadows. We monitored formation, growth, shrinkage and mortality of patches of a critically endangered early successional grass species Arctophila fulva var. pendulina for four consecutive years at the Liminka Bay in Finland. The data allow estimation of quality, magnitude and frequency of the wintertime disturbance and the growth during the summer. We formulated and parameterised a spatially explicit simulation model to predict the fate of the population in the area. Simulations with the fitted parameter estimates predicted that the area of A. fulva population will considerably decrease in the next 30 years. A parameter sensitivity analysis showed the probability of a new patch formation to be the most important factor for the population persistence, whereas changes in the dispersal distance, for example, are less important. The best way to enhance the persistence of the population is to promote the new patch formation. This could be done by transplanting rhizome fragments of the species to the suitable open areas in the shallow water where they are not immediately displaced by the later successional species. [Copyright &y& Elsevier]

The European Commission's ambitious construction and demolition waste (CDW) material recovery target has placed pressure on Finland to increase its CDW material recovery rate. It has been identified that using CDW fractions, e.g. waste wood, plastic, mineral wool and plasterboard, as raw materials for wood polymer composites (WPCs) may help in reaching the CDW material recovery target. The objectives of this study were to assess the environmental impacts of WPC production using specific CDW fractions, namely wood, plastic, plasterboard and mineral wool, as raw materials, and to compare these impacts with the baseline situation where these CDW fractions are treated with conventional waste treatment methods such as landfilling and incineration. The study focused primarily on the depletion of fossil hydrocarbons and climate change. The results indicate that, when compared to the baseline situation, the environmental impacts of CDW management can be decreased when CDW fractions are used in WPC production. By substituting WPCs for plastic or aluminium, considerable environmental benefits can be achieved in terms of the aforementioned impact categories. Due to the differences in the physical and mechanical properties of WPCs compared to plastic and aluminium, WPCs cannot necessarily substitute them in a mass-based ratio of 1:1. This was acknowledged in the study by identifying minimum substitution rates for different materials. For instance, the produced WPCs should substitute at least 6% of plastic and 8% of aluminium in order to decrease the impact on climate change compared to the advanced waste management scenario. Therefore, in applications where WPCs can be used as a substitute for these materials, WPC product design and development should be prioritised. • Environmental impacts of WPC production as a part of CDW management are assessed. • WPC production decreases the environmental impacts of CDW management. • Virgin material substitution has strong influence on the results. • The produced WPCs should primarily substitute plastic or aluminium. • Substituting wood by WPCs is not environmentally recommendable. [ABSTRACT FROM AUTHOR]