Molecular Soil Biology 2024, Vol.15, No.3, 109-117 http://bioscipublisher.com/index.php/msb 110 2 Snow Cover Dynamics 2.1 Definition and characteristics of snow cover Snow cover refers to the layer of snow that accumulates on the ground surface during winter. It plays a crucial role in the climate system by influencing ground temperature, light conditions, and moisture availability. Snow cover acts as an insulating layer, protecting the soil and vegetation from extreme cold temperatures and maintaining soil moisture levels by reducing evaporation (Oppen et al., 2022). The characteristics of snow cover, such as depth and duration, are essential in determining its impact on the ecosystem. For instance, deeper snow cover can enhance soil moisture and stabilize plant community composition by providing a consistent water source during the early growing season (Li et al., 2020). 2.2 Seasonal variations in snow cover Seasonal variations in snow cover are primarily driven by changes in temperature and precipitation patterns. During winter, snow accumulates and forms a protective layer over the soil and vegetation. As temperatures rise in spring, snow begins to melt, releasing stored water into the soil, which is crucial for the onset of the growing season (Chen et al., 2019). The timing of snowmelt can significantly influence plant phenology, with earlier snowmelt advancing the start of the growing season and potentially exposing plants to frost damage (Sanders and Templer, 2017). In contrast, delayed snowmelt can extend the period of soil moisture availability, benefiting plant growth and carbon uptake. 2.3 Factors influencing snow cover dynamics (e.g., climate change, geographical location) Several factors influence snow cover dynamics, including climate change, geographical location, and local environmental conditions. Climate change is a significant driver, leading to alterations in snowfall patterns, snow depth, and the timing of snowmelt. Rising global temperatures are causing a shift from snow to rain in many regions, reducing snow cover duration and depth (Wipf et al., 2009; Slatyer et al., 2021). Geographical location also plays a crucial role, with high-latitude and high-altitude regions experiencing more pronounced changes in snow cover due to their sensitivity to temperature fluctuations (Wang et al., 2018). Additionally, local factors such as vegetation type, topography, and soil moisture can modulate the effects of snow cover on the ecosystem. For example, in temperate China, thicker snow cover and later snowmelt generally enhance soil moisture and lengthen the growing season, promoting higher carbon uptake (Chen et al., 2019). Conversely, in alpine tundra ecosystems, reduced snow depth and earlier snowmelt can lead to increased plant mortality and altered species composition. 3 Impacts on Soil Moisture 3.1 Role of snow cover in soil moisture retention Snow cover plays a crucial role in soil moisture retention by acting as an insulating layer that prevents soil from freezing deeply and maintains higher soil moisture levels during winter. In temperate forests, reduced snow cover due to climate change can lead to increased soil freezing, which in turn affects soil moisture dynamics during the snowmelt period (Blankinship and Hart, 2012). Additionally, in arid grasslands, increased winter snowfall has been shown to enhance soil moisture in the early growing season, particularly in deeper soil layers, which is critical for plant growth and ecosystem stability (Li et al., 2020). 3.2 Mechanisms of snowmelt and water infiltration The process of snowmelt significantly influences water infiltration into the soil. Snowmelt provides a steady supply of water that infiltrates the soil, replenishing soil moisture levels. In northern hardwood forests, snow depth manipulation experiments have demonstrated that reduced snow cover leads to lower soil moisture levels during the snowmelt period, as less snow results in less water available for infiltration (Christiansen et al., 2018). Similarly, in temperate China, thicker snow cover and later snowmelt have been associated with increased soil moisture, which positively impacts vegetation growth by extending the growing season (Chen et al., 2019). 3.3 Effects of snow cover duration and depth on soil moisture levels The duration and depth of snow cover are critical factors that determine soil moisture levels. Longer and deeper snow cover periods generally result in higher soil moisture levels due to prolonged insulation and gradual water
RkJQdWJsaXNoZXIy MjQ4ODYzMg==