EXECUTIVE SUMMARY - UNESCO World Heritage

Pre-proposal No 2 SPATIAL VARIABILITY OF SOIL DEPTH AND TRANSPORT
PROPERTIES AS THE PRINCIPAL INDICATORS OF ENVIRONMENTAL SOIL FUNCTIONS
Soil depth will be measured by means of two methods:
• the electric resistivity tomography, which has been successfully applied in the Vtáãnik Massif already, along with the ground penetration radar
and digging;
• measurement of soil depth at forest road cuts.
In the massifs given in Table 1, the soil depth will be measured by 2-Delectric resistivity tomography along transects running in the North-South
direction parallel to the slope gradient. The electrodes arrays will be arranged so as to ensure the maximum resolution on the scale of tens of cm.
One measurement will capture approximately a section 250 m long. In the case of dificulties in discriminating between soil cover and bedrock, 1-
D electric sounding will be employed.
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1.2 Characterization of soil depth spatial variability
The sets of measured data will be analyzed as realizations of random processes. Their statistical distribution will be determined, whereas
deviations from the normal distribution will be screened by the Smirnov-Kolmogorov Test. The structure of spatial autocorrelation
will be studied by geostatistical methods, and specifically semivariograms. It can be assumed that the data sets will be effected by a
trend due to the growing thisckness of the slope deposits as a function of elevation and aspect. This possibility will be coped with by
the application of universal kriging with an external drift, which, according to the autors, provided a 38 % higher accuracy in estimating
a soil horizon thickness than the simple linera regression of the horizon depth and soil sloping.
1.3 Correlation with the abiotic environment
The topographic atributes will be calculated from a digital model of terrain. For the identification of factors, directly on indirectly effecting
the measured soil depth, factor analysis will be used for the set of climatic-topographic characteristics. The extraction of factor will
be performed by the principal component analysis. For any given data set, the number of used factors shall ensure that their cumulative
share on the total variance exceeds 70 %. Subsequently, crossvalidation of the predicted values will be carried out.
1.4 Correlation with the biotic environment
A similar approach will be taken in observable variables, themselves conditioned by the soil depth – and by that virtue also through the
total content of nutrients and water holding capacity. They are the tree species composition, the height of the medium stem in the forest
stand at the age of 100 years. The transects however must avoid areas subject to random cutting which changes the distribution of tree
heights and diameters in a non-systematic way. Under standard conditions and management systems, the height of medium tree at the
age of 100 years in a forest stand represents a good denominator for a comparison. It will be determined by means of the height curves
reproduced in the growth tables based on the upper height of the joint stand. It is known form literature that it is not sensitive to thinnings
and well reflects the quality of individual sites. By means of the Sybilla tree growth model (Fabrika 2006), opportunities of further
downscaling of the indicated approach will be studied.
Stage II: Modification of new fast method for the prediction of soil transport properties
Actions:
2.1 Derivation of mathematical relationships
The adaptation of new fast method for the prediction of the hydraulic conductivity of soils for field measurements will be carried out
based on the stochastic-convective assumption for the transport of water and solutes. For this purpose, formulas for the calculation of
_ (_) a K(_) from the indicator resident concentration will be derived leaning on the framework laid by Jury and Scotter (1994). It will enable
alternative approaches based on experiments defined by initial or boundary conditions, which shall render breakthrough curves of
the indicator (bromide) established by the Time Domain Reflectometry device connected to probes inserted horizontally into the soil profile
in the depth z, or form the resident concentrations of the indicator at a given time t, or alternatively, from the resident concentration
profiles of the Brilliant Blue dye tracer by means of image analysis.
2.2 Construction of the experimental apparatus
The breakthrough curves and concentration changes in the soil profile will be acquired through field measurements by means of an
apparatus specially built for this purpose. As opposed to sprinklers employed by other authors, it will feature nature-like a technique of
liquid indicator application in the form of drops similar to throughfall. The device will consist of an dispenser part, assembled from an
array of 400 x 400 syringe needles embedded in a teflon plate attached to a vibrator. The needed sprinkling intensity will be achieved
through a dosing pump operating in the range of 0,5–150,0 l.h–1.