Abstrakt
Land cover is changing rapidly in abandoned areas, former fields and pastures change into forests and shrubs, but now always. In this study, I tried to identify the main predictors of tree spreading in these areas.
The study site is located in the military area Hradiště, around the former village Tocov, it is 2,5 km long and 2 km wide and was abandoned in 1953. Due to lack of historical vegetation data on landscape scale, historical aerial photographs from years 1952, 1962, 1971, 1984, 1992, 1999 and 2005 were used as a primary source of data.
They were orthorectified, mosaicked and classified in two categories woodland and grassland. Changes between two successive classified images were modelled with generalized linear models with mixed effects (lmer).
Variables that were derived from digital elevation model, former land use and spatial variables were used. In order to verify the model predictions and for easier interpretation and visualization of results, a new application PEMZOK (Spatially explicit model of overgrowth of abandoned landscape) was developed.
The largest observed effect on the spread of trees had the distance to the nearest tree or shrub and density of trees in the vicinity (15 m x 15 m) and the wider neighbourhood (105 m x 105 m). Factors derived from digital terrain model lead to somewhat poorer prediction, but their impact was almost always significant, as well as the influence of the previous land use.
Most suitable for forest succession were places in former village and pastures, least suitable were former meadows. The results show the importance of spatial information for studies of vegetation change on a landscape scale and a noticeable influence of former land use, even after 50 years without management.