Twenty-Five Years of Reforestation on Nonforest Lands in Smolenskoe Poozerye National Park According to Landsat Imagery Assessment

Resumo

Reforestation on nonforest lands (including abandoned agricultural lands) in Smolenskoe Poozerye National Park has been assessed from summer Landsat image series taken in 1984 to 2016. The boundaries of nonforest lands have been delimited using cartographic materials from the 1970s–1980s. The continuous time series of reflectance for each pixel of spectral bands have been obtained by the simple moving average method. Thematic processing is performed using the Random Forest supervised classification algorithm. An analysis of the obtained cartographic products for different stages of recovery successions shows a monotonous decrease in open soil areas from 3651 ha (9.7%) in 1990 to 1489 ha (4%) in 2016. Almost 38% of nonforest lands had been covered by woody vegetation by 1990. The area of forest lands increased by about 18% over the next 25 years (generally due to deciduous species); half of this forest growth was observed during the 1990s. In 2015, 46.0% of the initial nonforest lands were naturally reforested by young birch forests and 9.6% were occupied by young pine forests. Ground survey data showed that the type of succession is primarily determined by the lithological conditions and species composition of the nearby forests and influences the pattern of preceding land use during the natural reforestation of nonforest lands.