Krzysztof Ostafin

One of the most widespread land cover change processes in European countries is the increase in forest cover. Forest expansion on abandoned agricultural land has played a major role in marginal mountain areas since World War II, and especially affected the post-socialist countries in Central and Eastern Europe. This study aimed at mapping forest cover change and forest succession in one of the communes of the Polish Carpathians ( Budzów ) over two time periods : 1977 – 1997 and 1997 – 2009. We identified rates of agricultural land abandonment and forest succession and assessed the dynamics of the process using aerial photographs, orthophotomaps as well as cadastral and census data. The results showed that Budzów commune experienced an expansion of forest cover from 40% in 1977 to almost 45% in 2009, and a significant increase in forest succession from 1% in 1997 to 10% in 2009, at the expense of agricultural land area ( 54% in 1977 and 40% in 2009 ). If the trend is widespread over the Polish Carpathians, the real forest cover may be much higher than follows from statistical data.

The paper compares the influence of dependent and independent vectorisation approaches on forest cover change analysis, with a hypothesis that the former reduces the number and area of sliver polygons. Independent vectorisation is based on separate creation of the vector layer for each period in the time series, while the dependent is based on modification of the successive vector layers. The comparison is based on three map sets – the second Austrian military survey ( 1861/1862 ), a Polish military map ( 1936 ) and a Polish topographic map ( 1979 ) and carried out in Szczawnica commune located in the Polish Carpathians. The results show that the overall differences between the two vectorisation approaches are low at the commune level, but the local differences, within the grids 500 × 500 m might be up to 30 – 40 %. Statistical analysis did not indicate any considered variable directly responsible for the differences, confirming that it is a randomly distributed phenomenon. The results show also that the dependent vectorisation cannot eliminate the existence of sliver polygons, but their number may be limited when compared to the independent approach. As the dependent vectorisation is much more time efficient, we conclude that it might be a better solution in the situation when  manual vectorisation is the most appropriate method of land use data acquisition from historical maps.

Previous studies concerning forest cover changes in the Polish Carpathians did not formerly extend further than the mid-19 th century, because of the lack of detailed cartographic materials. Earlier forest changes, especially their magnitude but sometimes even their direction ( deforestation, stabilisation or afforestation ) are poorly investigated. This paper shows how to extend a temporal sequence of forest cover data for Zawoja village in the Polish Carpathians using non-cartographic data from the late 18 th and early 19 th centuries. We used non-cartographic data from the first Austrian cadastral system, the so-called Josephinian cadastre, carried out in the 1780s, and its revision done in 1819 – 1820. These data were compared with the stable cadastre and its two revisions ( 1844 – 1898 ) and mostly later cartographic materials ( 1861 – 2014 ). Thematic coherence of cadastral and cartographic data, conformity of Zawoja village boundaries in the analysed period, as well as errors of the earliest cadastral measurements were investigated. The data acquired in the 1780s and 1819 – 1820 enabled the estimation of the productive and non-productive forest area as well as the area of pastures and meadows partly covered with forest. Though possible measurement errors could add up to 7 % of the total village area, the data clearly document the end of the deforestation phase ongoing in Zawoja until the first half of the 19 th century, and later relative stabilisation of forest cover during the second half of that century. Data from the late 18 th and early 19 th centuries indicate a change trend opposite to the later, frequently described stabilisation of forest cover and progressive afforestation. Using the unpublished data extracted from cartographic materials, we also show this latter part of long term forest cover changes, thereby presenting an example of forest transition in the Polish Carpathians.