###### Abstract  
Forests play important role in hydrological processes such as evapotranspiration, infiltration, surface runoff, and distribution of precipitation waters. This study evaluates soil water repellency (SWR) in a mountain forest area of Slovakia (Central Europe). Findings of previous studies suggest that the variability of SWR is associated mainly with differences in soil moisture. On the other hand, the role of soil organic matter (SOM) quality in spatial and/or temporal WR changes is less clear, particularly at the plot scale. To measure SOM quality, we used Fourier-transform infrared (FTIR) spectroscopy and thermogravimetry (TG). It was found that FTIR data and the results of thermal analysis are linked to dissimilar wettability of the studied soils. WR samples contained more aliphatic structural units in comparison to wettable soils, which showed a higher relative amount of polar functional groups. Thermogravimetric data suggest that SOM in all 45 samples is relatively labile. This is in accordance with strongly acidic pH and high C/N ratio. The amount of SOM degraded at around 250 \({}^{\circ}\)C was significantly correlated with SWR data and at the same time with FTIR peak areas characteristic for aliphatic structural units. This suggests that the accumulation of raw (labile) OM, containing nonpolar functional groups, supports the susceptibility of soils to WR. A significant portion of the variability in WR data was explained by multiple regression analysis, using field water content, FTIR peak areas, and SOM thermal characteristics as predictors. The results confirmed that even the soils occurring in a relatively humid and cold climate may show considerable WR during summer. soil water repellency; acidic forest soils; soil organic matter; functional composition; thermal stability 202  
The important factor which affects soil wettability is obviously soil moisture [6]. Usually, lower soil water contents in the field are associated with increased repellency, whereas for higher moisture levels a less repellent or wettable character of soil is expected. A negative correlation between the two variables was observed in many studies, but it is worth noting that this collinearity is a statistical approximation. Works that studied the phenomenon in detail in the laboratory suggest that soil wettability changes nonlinearly as a function of soil water content [7]. Nonlinear variation of WR with forming one or even two maxima in repellency as a result of decreasing soil moisture was reported by [PERSON] et al. [8]. Although soil moisture significantly affects SWR, the differences in soil wettability cannot be explained solely by the change in soil water content. There are additional parameters that need to be considered when assessing the susceptibility of soil to WR. The properties of SOM are important [9], as well as the characteristics of soil parent material [10]. Although there are the methods that enable study of the properties of SOM in detail, many of them include laborious sample preparation and the overall costs may be demanding when more samples are evaluated. The same is true for the analysis of inorganic soil components. Additionally, the results of advanced laboratory methods are often too complex, and they are rarely used as simple indicators of soil quality or as predictors in regression models. An exception in this regard is infrared (IR) spectroscopy that has been used as a tool for prediction of various soil properties [11; 12; 13]. Although cited studies usually analyzed a large number of samples and employed multivariate regression models, the attempts to predict SOM quality are scarce and works aimed at WR quantification are lacking. This work assesses the toposoil WR in forest ecosystem of the High Tatra mountains (Slovakia, Central Europe) recovering from the impact of a katabatic windstorm.