The accurate characterization of aboveground biomass (AGB) dynamics and their driving forces in sub-tropical forests is important to evaluate AGB's contribution to global carbon stocks. In order to estimate the effects of local variables on temporal and spatial patterns of AGB we investigated the variation of AGB in a 20-ha sub-tropical permanent plot. We found that the AGB was 153.7 Mg ha^-1 in 2005, and 149.3 Mg ha^-1 in 2010. During the five-year period, AGB changed due to tree mortality, growth (diameter at breast height, DBH) and recruitment. Medium-sized trees (DBH: 30–50 cm) were the largest contributor to total AGB. Both the tree species diversity index and the number of individuals within medium (DBH: 30–50 cm) and large (DBH: >50 cm) DBH ranges had significant positive effects on AGB. In addition, the abiotic factors such as elevation, slope, and convexity had negative significant relationships with AGB. The results indicate the importance of including forest community characteristics and environmental variables in forest carbon studies. This study also provides important data that can be used to develop and validate carbon cycling models for old-growth sub-tropical forests.

The aim of the study was to determine the structure of forest stands in rare Phyllitido-Aceretum communities, which grow in extremely harsh conditions – steep limestone slopes and rock shelves. Permanent research plots were established in five well-developed patches of Phyllitido-Aceretum communities from Kraków-Częstochowa Upland (Poland). Two of the plots were located in strictly protected areas of the Ojców National Park, whereas another three were established in the managed forests of Olkusz Forest District. The species composition of the forest stands was determined, including all dead and live trees and their diameters at breast height were measured. Moreover, the horizontal coordinates of each tree were measured to determine the spatial pattern of the trees. Ripley's L function was used for the spatial pattern analysis.

The research showed that the patches of Phyllitido-Aceretum communities are characterized by rich species composition of tree layers; nine species were found. There was no significant difference in the species composition between the living and dead trees and the shares of particular species were similar. The density and share of live trees in the phytocoenoses located within the strict protection zone were significantly lower than in managed forests. On the contrary, the same parameters when calculated for dead trees were significantly higher in phytocoenoses located in protected zones than in managed forests. The spatial distribution of the trees in all the analysed plots (except one) displayed a clumped pattern, which is observed in various spatial scales and reflects the habitat mosaics and life strategies of species typical for Phyllitido-Aceretum community.

The role of allelopathy in the displacement of given meadow species by wood small-reed (Calamagrostis epigejos) is not well recognized. The aim of this study was to evaluate and compare the influence of volatile and aqueous extracts from C. epigejos on initial recruitment of typical mesic meadow species (Daucus carota, Rumex acetosa, Festuca pratensis and Dactylis glomerata). The activity of allelochemicals contained within above-ground biomass, below-ground biomass and necromass of the donor plant was estimated. Using gas chromatography-mass spectrometry technique led to the identification of 19 compounds (alcohols, aldehydes, ketones and esters) in C. epigejos volatile extracts. Aliphatic alcohols were the main group of identified chemicals, including (Z)-3-hexen-1-ol acetate. The laboratory tests showed a significant inhibitory influence of volatile C. epigejos extracts on the growth of D. glomerata, D. carota and R. acetosa roots. The influence of aqueous C. epigejos extracts on selected meadow species was less evident. Only the seeds of D. glomerata and F. pratensis were found to be susceptible to water extracts of above-ground C. epigejos biomass. The seed germination was stimulated by the extracts at low concentrations but inhibited at higher concentrations. Among the tested plants only the growth of F. pratensis seedlings was inhibited by aqueous extracts obtained from all examined C. epigejos parts. In regarding to the other test species the effect of C. epigejos extracts was neutral or positive. The results suggest that C. epigejos has a allelopathic potential to suppress the growth of co-occurring grassland species.

In the managed forest of temperate Europe, black cherry (Prunus serotina) is one of the most important invader species. Among the ecological traits enabling its expansion in forest stands, the role of chemical compounds released naturally by this plant into the environment still remains unclear. The aim of this study was to determine the influence of black cherry leaf litter on the germination and growth of Scots pine (Pinus sylvestris) seedlings. Laboratory bioassays with extracts from newly fallen and decomposed leaves showed a phytotoxic effect on root elongation and a slightly weaker negative effect on stem growth of pine shoots. The inhibitory effect increased with the gradient of leaf extract concentration. Furthermore, a significant negative correlation was observed between condensed tannin content in decomposed leaf litter of the black cherry and the pine root growth. The results are discussed in the context of black cherry litter properties which could interfere with natural regeneration of pine forests.

Roosting in various shelters allows saving energy, especially in winter, thus hole nesting birds, like tits, search for places suitable to spend cold nights. Because the environment probably does not provide enough shelters for all birds from a winter flock to roost, a competition for best sites, as nest boxes, probably occurs. Therefore, the aim of this study was to describe the pattern of using the nest boxes by birds for roosting during three consecutive winter seasons and to determine the structure of a group of roosting birds in relation to the winter flock. Tits were captured and marked; daily controls of nest boxes were performed to find out which of them the tits used for roosting and subsequently, birds entering these boxes were caught at night. Great tits Parus major were the most abundant species roosting in the studied boxes with proportion of blue tits Cyanistes caeruleus differed between years. Young individuals prevailed among the birds roosting in nest boxes. However the age and sex structure of great tits roosting in nest boxes was similar to that observed in winter flocks, which was in contrast to earlier studies that found that the males and older individuals, high in the social hierarchy of the flock, will take over these boxes. The size of winter flock differs strongly among winters, thus it is possible that the level of competition for these roosting sites also varies between the years.

Forest fragmentation by urbanizing and developing roads and fields is common in Japan; thus, the Siberian flying squirrel (Pteromys volans) population may decrease in the future. This study examined the effects of urbanization on P. volans by clarifying their home ranges and nest arrangements. Ten flying squirrels were captured and radio-telemetrically tracked from 2005 to 2007 in Obihiro City in eastern Hokkaido (Northern Japan). Males had significantly larger 100% MCP (minimum convex polygon) areas (mean ± SD; 6.5 ± 5.1 ha) and 95% MCP areas (3.6 ± 1.3 ha) than females (1.8 ± 1.0 ha and 1.0 ± 0.5 ha, respectively). Also the core area of males (1.2 ± 1.1 ha) was larger than females (0.2 ± 0.2 ha), though this difference was not significant. Males and females used more nests located inside than outside of their core areas. Distance from the core area edge to the nest located outside the core was longer for males (78.6 ± 139.9 m) than for females (39.7 ± 39.9 m), but this difference was not significant. Siberian flying squirrels in urban forests likely show similar ecology with flying squirrels in consecutive forests; however, they might change their behavior to share resources with others because urban forests restrict nest and food resources.

Galls formed by insects can act as sinks for nutrients and attract other herbivores to feed on gall tissues, which initiates interspecific competition, sometimes nurturing the herbivorous insects and restraining the gall-inducing insect, particularly when this competition is plant-mediated. Here, to our knowledge, we provide the first evidence of a close relationship between a gall insect, Hartigiola annulipes (Diptera: Cecidomyiidae), and a sap-sucking, Liothrips setinodis (Thysanoptera: Phlaeothripidae). The thrips were observed feeding on young H. annulipes galls, formed on the common beech (Fagus sylvatica) leaves during spring. Among randomly chosen beech trees, 100 current-year shoots were surveyed to determine the number of H. annulipes galls and the presence of thrips on the leaves. Our results show that L. setinodis specimens were found significantly more frequently on leaves infested by the galler than on uninfested leaves. The consequences of feeding thrips at the site of gall formation are not known yet, but it can be supposed that they are unfavourable to the gall insects and therefore could be beneficial for the host plant.