Estimation of the level of recreational transformation of public green spaces by indicators of soil penetration resistance

Abstract

The article shows the possibility of assessing the level of recreational transformation of public green spaces in terms of the soil penetration resistance and proved that the profile distribution of soil penetration resistance values is an information valuable indicator for establishing the level of recreational load. The measurement of soil penetration resistance within the park Novooleksandrivsky (Melitopol, Ukraine) was performed at 179 points on a quasi-regular grid with a distance between the points of accounting 30–40 m. The soil penetration resistance was revealed to be naturally increases with the growth of the depth of the soil layer from 2.42±0.023 MPa in the soil layer 0‒5 cm to 9.86±0.078 MPa in the soil layer 95‒100 cm. The process of increasing soil penetration resistance with depth is not monotonous, resulting in the presence of local penetration resistance at a depth of 50‒55 or 55‒60 cm. The variability of soil penetration resistance within one layer, which is described by the variation coefficient, is in the range of 6.98‒20.54%. This indicator naturally changes by profile. The high level of variation is peculiar to the top layer of soil 0‒5 cm, where the coefficient of variation of soil penetration resistance is 12.94 %. It is proved that under the influence of recreation there is a formation of functional layering of soil, expressed in the existence of structures in which layers of soil with greater soil penetration resistance are degraded by layers of less penetration resistance. The presence of such features can cause a complex of negative phenomena, which are associated with restriction of moisture penetration into the soil, reducing the migration capacity of air in the soil, limiting the growth of root systems of plants and the movement of animals. Functional layering can form local waterproof horizons that will limit the soil’s ability to absorb moisture. Correlational analysis of the connection of soil penetration resistance and the indicator of recreational load allowed to establish that with the increase of recreational pressure soil penetration resistance increases. The established correlational dependence of soil penetration resistance indicators and the assessment of the level of recreational load allows us to consider the possibility on the basis of penetration resistance data to quantify the level of recreational load. We completed this task with the help of multiple linear regression with the procedure of step-by-step inclusion of predictors in the model. The regression model is statistically significant and has made it easy to explain 46% of the varying indicators of recreational load. The step-by-step inclusion procedure provided an opportunity to choose the 10 most informative predictors for use in the model. The following levels of recreational load were established: low level, below moderate, moderate level, above moderate to high levels, as well as the procedure for indication of these levels based on soil penetration resistance data at different depths. The levels of recreational load were indicated on the basis of the procedure of classification trees on the soil penetration resistance data

Keywords

• recreation
• descriptive statistics
• regression analysis
• soil properties
• urbanization