CORONA imagery in the analysis of the forest-tundra ecotone in Kuznetsk Alatau (Orligtaskhyl Mountain)

Abstract

Changes in the forest-tundra ecotone of Orligtashyl mountain (Kuznetsk Alatau) were analyzed based on the available satellite CORONA (1971) and Wordlview (2013) imagery. Forest stands were identified on the Worldview scene using Iso cluster classification. On the CORONA scene stands were differentiated from the background area using statistical analysis of histogram of the identified classes’ brightness values and were harmonized with the classification of the Wordlview imagery. Kappa-statistics showed good accuracy (κ = 0.93) of the Wordlview imagery classification and the average for CORONA (κ = 0.67). Area of stands increased by ~38% during the analyzed period. Maximal area increase was observed on the south-eastern warm slopes. Significant changes were determined on the elevational boundary of the ecotone where the stands’ elevation boundary shifted up by ~9 m (0.2 m/yr.). GIS analysis revealed that trees form elongated clusters mainly directed across the slope. Observed changes occurred along with summer temperature increase during 1971–2013 by 0.3°С/decade (r2 = 0.32, p < 0.01).