Abstract: Tree species composition of Central European alluvial hardwood forests has changed with the arrival of flood-intolerant and mesic species. Within this group of tree species, a dominant role is played by field maple (Acer campestre) and European hornbeam (Carpinus betulus). This study was performed in the Lanzhot natural forests at the confluence of the Morava and the Dyje Rivers, which are considered to be one of the most natural alluvial hardwood forests in Central Europe and where the absence of the direct influence by humans for 75 years has allowed spontaneous development. Our basic research questions were as follows: (1) does the mutual proportion and structure of field maple and hornbeam populations change along an elevation gradient of 4 m in an alluvial forest and (2) does the tree spatial pattern of field maple and hornbeam change along this gradient? The study found significant differences in the development of hornbeam and field maple populations with increasing elevation in an alluvial hardwood forest. While the strength of the hornbeam population clearly increases with increasing elevation, the field maple population does not. Compared to hornbeam, field maple is closer to the r-strategy side of the K-r continuum on alluvial sites. Our study reveals that field maple and hornbeam are mainly distributed in clusters on alluvial sites. Both species are concentrated at places with lower flooding intensity, i.e. to higher elevation sites. The study shows that tree spatial patterns could change dynamically along a short elevation gradient in alluvial hardwood forest.

Abstract: The aim of this work was to evaluate the effects of mulching with compost on growth and leaf gas exchange of two widely-used ornamental trees in comparison to local nursery management standards. In addition, effects on soil respiration, soil temperature and water evaporation from soil were determined. An equal number (180 each) of uniform hedge maple (Acer campestre L.) and 180 hornbeam (Carpinus betulus L.) were planted in an experimental plot located in Pistoia. Treatments compared were: 1) chemical weeding by herbicides; 2) natural grass cover, mowed twice per year; 3) harrowing once a year; and 4) mulching with mixed compost (50% green+50% from household waste, 5 to 10 cm thick). Over a two-year period, stem diameter, shoot extension and leaf gas exchange were measured. In the second year leaf chlorophyll content, chlorophyll fluorescence, soil respiration, soil evaporation content and soil temperature were also recorded. Mulching with compost influenced shoot extension and stem diameter growth of field maple and white hornbeam. Plants grown with natural grass cover had, generally, smaller stem diameters and shoot growth than the other treatments. Leaf gas exchange, chlorophyll content and chlorophyll fluorescence were influenced by the different treatments. Soil respiration was unaffected by the different treatments while soil temperature was significantly lower in mulched plots.

Abstract: The aim of this study was to assess the effect of temperature on the germination response in six origins of Acer platanoides and Acer campestre seeds Seeds of both species were exposed to four methods of stratification: cold (3 °C) and warm (20 °C), with and without sand-peat medium The highest percentage of germination (5475%) was obtained, for Acer platanoides, when the treatment was conducted at 3 °C The initiation of germination with a low percentage of germinated seeds (1275% to 2225%) determined the initiation of secondary dormancy for the majority of A platanoides seeds In the case of the A campestre seeds, the pretreatment phase in cold environment (19weeks) proved to be too short for these origins

Abstract: Summary 1. This account presents information on all aspects of the biology of Euonymus europaeus that are relevant to understand its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation. 2. Euonymus europaeus (Spindle tree) is a native gynodioecious deciduous shrub whose distribution is mostly associated with fertile soil at higher pH values. It is frequently found in hedgerows and woodland edges but also in woodland as an understorey shrub, often with Fraxinus excelsior, Acer campestre and Quercus species, and in open scrub over limestone with Cornus sanguinea. Its seed is widely dispersed by birds and rodents. 3. Euonymus europaeus is winter hardy and shade tolerant and, when young, its green shoots with stomata fix c. 15% of its CO2. The aril is eaten by a range of animals but the seeds are poisonous and the whole plant contains compounds of medicinal and veterinary value. 4. Euonymus europaeus acts as the winter host to two important crop pests: the black bean aphid (Aphis fabae) which feeds on field beans (Vicia faba) and sugar beet (Beta vulgaris), and the peach potato aphid ⁄ green peach aphid (Myzus persicae) a widespread pest of a large number of crops. Despite removal of E. europaeus from hedgerows and woodlands in the past, its present populations appear stable.