The importance of marginal habitats for the conservation of old trees in agricultural landscapes

摘要: Abstract Deterioration of unfarmed habitats resulted in a considerable decrease biological diversity agricultural landscapes. The most important elements cultural landscapes determining high level are woodlots and the trees themselves. This paper presents results study carried out 2000–2001 on distribution number champion (heritage) area 5480 ha intensively managed land (Lower Silesia, south-western Poland). fieldwork consisted localizing measuring all tree specimens an fragment Wroclaw Plain Silesia Province, SW Champion were found 116 (50.1%) 228 surveyed sites. overall was 493, belonging to 34 species. numerous native species (276 specimens). four cultivated amounted 40% trees. largest percentage with at least one specimen characteristic for manor parks (100%), lowest—for village areas (27.8%) mid-field clumps (39.2%). A high, statistically significant correlation between size clump it contained. highest water-edge hedgerows. current occurrence landscape is result many centuries rural management. Apart from exotic trees, introduced mainly aesthetic reasons inhabited (villages, parks, cemeteries), have survived woodlots, planted past due their economic value (Quercus robur, Fraxinus excelsior, Ulmus laevis). pattern indicates that some them may arrived here as natural processes, such dispersion (e.g. Crataegus monogyna Rhamnus cathartica occurred clumps).