Seasonal and interannual ecophysiological responses of beech (Fagus sylvatica) at its south-eastern distribution limit in Europe

Due to its wide European distribution and its drought-susceptibility, beech (Fagus sylvatica L.) received intensive attention recently in the light of global warming. Contrary to central European beech ecosystems, little is known about the ecophysiology of beech at its south-eastern European distribution limit. Here we tested whether climatic fluctuations during a three-year period affected the ecophysiology of a beech site in Greece. Attention was paid at comparing our findings to the intense effects the 2003 extreme drought had on beech forests in central Europe.     

Alley coppice—a new system with ancient roots

Context

Current production from natural forests will not satisfy future world demand for timber and fuel wood, and new land management options are required.

Aims

We explore an innovative production system that combines the production of short rotation coppice in wide alleys with the production of high-value trees on narrow strips of land; it is an alternative form of alley cropping which we propose to call ‘alley coppice’. The aim is to describe this alley coppice system and to illustrate its potential for producing two diverse products, namely high-value timber and energy wood on the same land unit.

Methods

Based on a comprehensive literature review, we compare the advantages and disadvantages of the alley coppice system and contrast the features with well-known existing or past systems of biomass and wood production.

Results

We describe and discuss the basic aspects of alley coppice, its design and dynamics, the processes of competition and facilitation, issues of ecology, and areas that are open for future research.

Conclusion

Based on existing knowledge, a solid foundation for the implementation of alley coppice on suitable land is presented, and the high potential of this system could be shown.     

Expression patterns of influenza virus receptors in the respiratory tracts of four species of poultry

The primary determinant of influenza virus infectivity is the type of linkage between sialic acid and oligosaccharides on the host cells. Hemagglutinin of avian influenza viruses preferentially binds to sialic acids linked to galactose by an α-2,3 linkage whereas hemagglutinin of human influenza viruses binds to sialic acids with an α-2,6 linkage. The distribution patterns of influenza receptors in the avian respiratory tracts are of particular interest because these are important for initial viral attachment, replication, and transmission to other species. In this study, we examined the distribution patterns of influenza receptors in the respiratory tract of chickens, ducks, pheasants, and quails because these species have been known to act as intermediate hosts in interspecies transmission. Lectin histochemistry was performed to detect receptor-bearing cells. Cell-specific distribution of the receptors was determined and expression densities were compared. We observed species-, site-, and cell-specific variations in receptor expression. In general, receptor expression was the highest in quails and lowest in ducks. Pheasants and quails had abundant expression of both types of receptors throughout the respiratory tract. These results indicate that pheasants and quails may play important roles as intermediate hosts for the generation of influenza viruses with pandemic potential.     

Spatial structure and inter-firm networks of technical and information producer services in Seoul,Korea

A spatial and sectoral reorganisation of producer services has begun to change the urban structure of Seoul. In addition to the existing centre of the CBD, two areas, Kangnam and Yongdeungpo, have emerged as the new centres of producer services in Seoul resulting from relocations from the CBD and the location of firm start-ups and spin-offs, so creating a multi-centred structure. There is a difference between the centres related to the fact that Kangnam is specialised in advanced services and has strong local networks among service firms, firms in Yongdeungpo have strong forward linkages to nearby manufacturing firms and to larger producer service firms, while firms in the CBD are relatively older and have much more intensive overseas ties. This outcome illustrates that shifts in the organisation of producer services in favour of outsourcing have been felt in shifts in spatial patterns. These new structures illustrate that producer service location and operation have a powerful influence upon the pattern of development in Seoul.