<p>When simulating soil water content (SWC) and dynamics, the reservoir cascade scheme (RCS) approach is considered appropriate in cases when number of parameters for model calibration and validation is limited. This is often the case in Mediterranean karst soils, where due to high rockiness and shallow soil depths it is often difficult to set dense measurement network. In this study, a 1-D model which simulates SWC using RCS approach was developed for a location in central Spain. The soil on the studied site has silt loam texture and is developed on dolomite marbles. The model simulates SWC at daily resolution for six layers in soil that range from 0-50 cm depth, and has three different configurations. Configuration 1 considers only basic RCS module, while configurations 2 and 3 simulate preferential flows in soil as well. Therefore Configuration 2 considers RCS module together with continuous preferential flow module, where between 1 and 5% of available SWC is drained from each soil layer every day. Configuration 3 considers discontinuous preferential flows in addition to two previous modules. Discontinuous preferential flows are active in cases of rainfall events that occur during prolonged dry periods. Simulated SWC values are compared with SWC values measured at five depths in soil, so model parameters are iteratively adjusted to optimize the model results. The simulation produced the best results when implementing Configuration 3: when matrix flow and two kinds of preferential flow are assumed. The model shows that preferential flows could significantly contribute to recharge and should be given more attention in soil hydrological models, especially in karst terrains. It is expected that the model can be implemented in a wide range of locations with karst soils, since it requires limited number of input parameters, but in the same time provides a detailed simulation of soil drainage processes and recharge.</p>
<p>Pedogenic carbonates are secondary carbonate deposits that are often found in soils developed over carbonate rocks in Mediterranean region. Their formation is a result of dissolution and reprecipitation of existing geogenic, biogenic and/or pedogenic carbonates. Intensity of the dissolution processes affecting carbonates depends on multitude of factors but is mostly controlled by soil water drainage and concentration of soil air CO<sub>2</sub>.</p><p>While percolating through soils and carbonate rocks, water dissolves carbonate minerals until reaching saturation state. Change in environmental conditions impacting concentration of soil air CO<sub>2</sub> (e.g., increase of temperature, decrease of soil water content), change of the soil water chemistry and evapotranspiration can lead to supersaturation of water in regard to Calcite and formation of pedogenic carbonates. In case of physicochemical precipitation, pedogenic carbonates precipitate in form of diffuse, small crystals and nodules. On the other hand, biologically influenced precipitation commonly results in different morphologies such as rhizolits, bacterial/fungal mats, etc. Pedogenic carbonates can occur in wide range of climates, thus their morphology and accumulation depth depend on mean annual precipitation. If sufficient time has passed, translocation of carbonates in the soil profile results in formation of calcic horizon.</p><p>We studied a 0.6 m deep Red Mediterranean Soil profile in Dalmatia (Croatia) having a calcic horizon at the bottom. Diffuse calcite particles and small nodules forming this horizon record different events of dissolution and precipitation. Based on data on soil temperature, soil water content, soil bulk electrical conductivity and soil air CO<sub>2</sub> collected during a 3-month monitoring period we developed a thermodynamic model for dissolution and precipitation of calcite in the soil. Results show that soil air CO<sub>2</sub> (affected by soil water content and temperature) is the main control of the calcite reactions. Furthermore, during the monitoring period 83% of the calcite dissolved was reprecipitated as pedogenic carbonate. Therefore, although dissolution is the main process governing denudation rate of karst areas (i.e., lowering of the surface), formation of pedogenic carbonates in soils could impact denudation rate of carbonate terrains.</p><p><strong>Acknowledgements</strong></p><p>This work is part of the research project &#8220;Inter-comparison of karst denudation measurement methods&#8221; (KADEME, IP-2018-01-7080) and &#8220;Young Researchers&#8217; Career Development Project &#8211; Training New Doctoral Students&#8221; (DOK-2021-02) financed by Croatian Science Foundation.</p>
Parent material is an important factor in soil formation, especially in soils formed in Mediterranean region dominated by calcareous sedimentary rocks. Their basic properties (mineralogical composition, coherence, and permeability for water) influence the resistance to weathering and type of weathering products, its amount, particle size distribution, as well as the intensity of physicochemical transformations within the original rock residue. Thus, the aim of this study was to investigate the impact of parent material on soil properties in southern part of Krka National Park, Croatia. Weathering of carbonate parent material (limestones, dolomites, conglomerates, marls) along with other soil forming factors was the base for soil development in this area. Thus, Calcocambisols and Terra rossa, typical and ilimerized are the most widespread soil types, while Calcomelanosols, Colluvium and Rendzinas are as well represented, but in much lesser extent. Soil depth, presence of coarse fragments and carbonate content in these soils vary considerably depending on parent material, although factors such as relief, vegetation and anthropogenic impact cannot be neglected. In general, shallow soils ( 35 cm) were formed on limestones and conglomerates, while medium deep soils (35-70 cm) were formed on marly substrates. The content of coarse fragments of variable size in soils (fine gravel 2-6 mm to boulders 60-200 cm) is related to different weathering processes of parent material. The presence of carbonate nodules on soil surface and within soil profile also indicates pedogenetic processes related to different types of carbonate parent material.
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