Micromorphological features of soils formed on calcium carbonate–rich slope deposits in the Polish Carpathians

Seven soil profiles developed on calcium carbonate–rich slope deposits in the Polish Carpathians were studied in order to:i)determine the micromorphological features of heterogeneous soils formed in a carbonate depositional environment,and ii)track primary and secondary calcium carbonate forms and their distribution in such stratified soils.Three cases of soils with different arrangements of calcium carbonate were distinguished,controlled mostly by slope processes.For instance,the increasing content and random distribution of angular and subangular rock fragments found in the overall soil matrix and the irregular coarse:fine size limit suggested different intensities of accumulation and mixing of soil material transported along the slope.Slope processes,together with the calcium carbonate content,mineralogical characteristics and texture influenced the type and arrangement of the bfabric pattern.The calcium carbonate distribution within the soils,besides the obvious inheritance from parent material,was governed by the translocation and mixing of deposits on slopes.The climatic conditions prevailing in the area favour the development of secondary forms of calcium carbonate.However,only three of the seven studied profiles contained pedogenic forms of calcium carbonate,yet they were distributed randomly.The occurrence,distribution and preservation of secondary carbonates depended on the content of primary calcium carbonate and soil features such as texture.The transported material down the slope may indicate a very low content of primary calcium or lack thereof,hence its pedogenic forms could not be created.

Humus horizon development during natural forest succession process in the Polish Carpathians

As a result of socio-economic changes and land abandonment,the main ecological driver of the Carpathian landscape is the progression of the natural forest succession process.Thus,aspects of this process have become worthy of attention,especially in the context of carbon sequestration and the management of protected areas.Soil processes,especially within the topsoil,are some of the most susceptible to change,due to the accumulation of organic matter during such land-use transformations.The purposes of this study were to investigate the differences in topsoil development using the A Horizon Development Index(ADI)and to study the composition of humic substances and advanced organic matter humification in different land-use areas in selected Carpathian national parks,i.e.Bieszczady,Magura and Pieniny National Parks in southern Poland.Additionally,a goal of this study was to compare the ADI and the spectroscopic coefficients of humic substances as indicators of the degree of humus horizon shaping as well as advanced organic matter humification.In total,ten transects were selected,each consisting of three different land-use areas:semi-natural meadow,successional forest and old-growth forest.Soil colour was determined in fresh and air-dried samples using the Munsell colour chart.In air-dried soil samples p H,soil texture,total organic carbon and total nitrogen were measured.Humic substances were extracted and further characterized by UV-VIS spectroscopy.The ADI confirmed the influence of natural forest succession on soil colour darkening and the development of the uppermost soil layer.Spectroscopic analyses of humic substances showed two different patterns depending on soil depth.In the 0–10 cm layer,natural forest succession reduced the rate of the humification process and decreased the degree of maturity of fulvic acids;in the 10–20 cm layer,it led to an increase in the rate of the humification process and a decrease in the content of humic and fulvic acids at the beginning of the transformation.The comparison of two different indicators of soil development–the ADI and the spectroscopic coefficients of humic substances(Q_(4/6),Q_(2/4),Q_(2/3),Δlog K)–indicated that these indexes are based on different features of soil and cannot be used interchangeably.