Soil moisture in mountain spruce stand

Abstract

Mountain forests are among the main components of natural environment in Slovakia. They grow mainly in areas with cold climate, on poor soils with unfavorable reaction, often very acidic (pH in H<sub>2</sub>O < 4.5) and with nutrient deficit. Immissions and acid rain attack forests to a great extent. Global climate changes also represent a new threat. Extremes in air temperatures, excessive amounts of precipitation or on the other hand the lack of water from precipitation, torrential rains or long-lasting drought periods are recorded as a result of a higher amount of heat energy accumulation from the greenhouse effect. Spruce forests are most endangered. Spruce with its root system concentrated in the upper soil layers, where also the highest amount of toxic elements accumulates, suffers more and more from dry and warm periods and it begins to wither due to drought. The occurrence of hydropedological cycles with a low or insufficient supply of available water in the soil is most frequent during summer (July, August). If the soil water potential values approach the value of the wilting point, an expressive decrease in transpiration is observed during the day, whereas its daily course is also suppressed. Gradual soil drying up from the upper layers towards the deepest ones of the physiological profile of soil represents a change in soil moisture stratification, especially after moistening the upper layers of soil with water from atmospheric precipitation. The deeper soil layers need not be re-saturated in such a case. Under drought the whole physiological profile of soil dries up in a relatively short time. Trees are exposed to a strong physiological stress in such conditions and after longlasting drought periods they can get into the state of total exhaustion.

Assessment of Landscape Retention Water Capacity and Hydrological Balance in Traditional Agricultural Landscape (Model Area Liptovská Teplička Settlements, Slovakia)

“…The coefficient of the SWRC calculation, using the algorithm published by [33], took into account a wide range of evaluated soil attributes (Table 5, Figure 5) for which we assumed a correlation with the natural phenomenon under evaluation. The overall calculation of LWRC values also included coefficients based on a study [2] on the volume of water retained by an SLS. Categories with a lower LWRC value of 1.5-6 have a low potential for retaining water in the landscape.…”

“…In total, there were 26 classes identified in the study area (Figure 4). An adjusted weighting coefficient was assigned to the elements of the SLS according to the work of [2] in terms of their significance for water retention capacity. The historical structures of the agrarian landscape were identified according to [36] and verified during a field survey in the years 2015-2017.…”

“…We assigned a coefficient to each element of land cover according to the Tužinský algorithm [2], which we adjusted based on field inspections and experience. The boundaries of narrow-strip fields usually have the character of terraces or ramparts running along the contour, along the slope, or obliquely.…”

The phenotypic and genetic effects of drought-induced stress on wood specific conductivity and anatomical properties in white spruce seedlings, and relationships with growth and wood density

“…From the dry mass, the volume of water to add to reach the desired humidity level for each of the treatments was determined. The estimation of the optimal substrate water content was based on previous studies which showed that the optimal soil water content for spruce growth is between 60 and 80% of the maximum capillary capacity (Kutıĺek and Nielsn, 1994;Tuzǐnsky, 2002). Another similar study on Norway spruce used 60-80% of maximum capillary capacity for the control treatment, 40-59% of maximum capillary capacity for mild drought stress, and 20-39% of maximum capillary capacity for severe drought stress (Ditmarováet al, 2010).…”