Changes in the extent of non-forest woody vegetation in the Novodvorsko and Žehušicko region (Central Bohemia, Czech Republic)

Abstract

Changes in the extent and occurrence of non-forest woody vegetation in the agricultural landscape of the Novodvorsko and Žehušicko region in the Central Bohemia during the last 60 years are presented in the paper. The study is based on a comparison of data (landscape structure indicators) from two time horizons - 1950 and the present (2011). Historical black and white aerial photographs from 1950 and color orthophotomaps from 2006 were used as data sources. Furthermore, the present state of the vegetation was investigated and specified by field mapping in 2011. The extent and changes of non forest woody vegetation were observed in natural (biochores) and cultural (landscape character areas) units with the aim to find out differences dependent on natural and cultural conditions. Results confirm that the quantity as well as the distribution of elements of non-forest woody vegetation changed during the last 60 years in an important way. Significant decrease in the area of non-forest woody vegetation and extinction of many important biotopes are among the main results of the work. The study provides strong evidence that changes in land use and landscape structure have a great influence on non-forest woody vegetation in all aspects. At the end of the paper, the reasons for the changes are discussed. In general, intensification and mechanization of agriculture has caused extinction of fine-grained landscape microstructure especially as to arable lands connected with removal of dispersed vegetation structures. Straightening of watercourses and destruction of meanders with their riparian vegetation has had the same effect.