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Application of Sentinel-2 and EnMAP new satellite data to the mapping of alpine vegetation of the Karkonosze Mountains

Jędrych M., Zagajewski B., Marcinkowska-Ochtyra A.

Polish Cartographical Review

2017

Vol. 49, No. 3

107--119

Effective assessment of environmental changes requires an update of vegetation maps as it is an indicator of both local and global development. It is therefore important to formulate methods which would ensure constant monitoring. It can be achieved with the use of satellite data which makes the analysis of hard-to-reach areas such as alpine ecosystems easier. Every year, more new satellite data is available. Its spatial, spectral, time, and radiometric resolution is improving as well. Despite significant achievements in terms of the methodology of image classification, there is still the need to improve it. It results from the changing needs of spatial data users, availability of new kinds of satellite sensors, and development of classification algorithms. The article focuses on the application of Sentinel-2 and hyperspectral EnMAP images to the classification of alpine plants of the Karkonosze (Giant) Mountains according to the: Support Vector Machine (SVM), Random Forest (RF), and Maximum Likelihood (ML) algorithms. The effects of their work is a set of maps of alpine and subalpine vegetation as well as classification error matrices. The achieved results are satisfactory as the overall accuracy of classification with the SVM method has reached 82% for Sentinel-2 data and 83% for EnMAP data, which confirms the applicability of image data to the monitoring of alpine plants.

Effect of snow patches on vegetation in the high-mountain nival gullies (Tatra Mts. Poland)

Kozłowska Anna, Rączkowska Zofia

Polish Journal of Ecology

2006

Vol. 54, nr 1

69-90

The purposes of the present paper are: a) to characterise the spatial pattern of vegetation in the high mountain nival gullies, b) to assess the factors determining the differentiation of vegetation in the gullies with particular consideration of the role of snow patches, and c) to present the similarities and the differences of relations between plant species composition and thickness and duration of snow patches existing in the gullies and in their vicinities.The studies have been carried out in the Polish part of Tatra Mountains (19[degrees]45[minutes]36[second] - 20[degrees]08[minutes]00[second] E and 49[degrees]10[minutes]42[second]-49[degrees]20[minutes]05[second] N), in two nival gullies, located above the upper timberline (i. e. 1500 m a.s.l) . The coverage of each plant species was correlated with the thickness of a snow patch on the basis of the sample plots of 0.25 m^2 (n = 889), located along the vertical transects in the gullies. The relations between variables were established based on the Spearman rank correlation analysis. In order to present the general character of relations between the features analysed the PCA method was applied. The differentiation of vegetation reflects the habitat conditions, which result from the terrain topography, morphometry of the relief forms, as well as from the thickness and duration of the snow patch. In the nival niches there are the species which positively or negatively correlate with the snow patch thickness. It is manifested through the decrease in the number of species as the snow thickness increases. Two species, Luzula alpino-pilosa (Chaix) Breistr. and Festuca picta Kit., can be accepted as indicators of the sites with the long persistent snow cover. The negative correlation of the plant species coverage with the snow patch thickness is not so unambiguous, since the role of the snow patch depends upon the duration of its persistence. The study showed the effect of factors featuring the high-mountain vegetation at different spatial scale, i. e. according to altitude, local sites and micro-site factors connected with the place inside the gully with the snow patch.