Using ALS data to estimate afforestation and secondary forest succession on agricultural areas: An approach to improve the understanding of land abandonment causes

The aim of the article is to identify the relationships between the phenomenon of land cultivation abandonment and spatial features of parcels that influence the economic effects of land cultivation. The study covered submontane areas with unfavorable soil and climate conditions which, nevertheless, were a place of intensive agricultural activities until the beginning of the 21st century. The study area is also characterized by unfavorable parameters of land fragmentation. The study covered part of the Malopolska Region in southern Poland with an area of 1745 km(2). The area is divided into nearly 370,000 parcels. The study was based on ALS data with a density of 8 points/m(2). On its basis, a number of categories of high vegetation were determined and then processed into a 1 x 1 m grid structure. This allowed to define the height structure of vegetation in every parcel. Other features, including land use status at the end of the 20th century, were derived from cadastral databases and digital soil quality maps. To explain the causes of observed forest expansion, the following diagnostic features were used in the models of logistic regression: size of a parcel, its width, slope, soil quality, and accessibility to the road network. The results allow to formulate an unexpected conclusion: unfavorable spatial features of parcels, negatively affecting the profitability of agricultural production, have no statistically significant influence on the decision of land cultivation abandonment.