Molecular Soil Biology 2024, Vol.15, No.3, 109-117 http://bioscipublisher.com/index.php/msb 113 5.3 Long-term ecological impacts of changing snow cover patterns Long-term changes in snow cover patterns due to climate change are expected to have profound ecological impacts. In Arctic and alpine tundra ecosystems, altered snow conditions can affect vegetation, plant-animal interactions, permafrost conditions, microbial processes, and biogeochemical cycling. For example, long-term deepened snow in tundra regions has been shown to promote the growth of evergreen shrubs, increase aboveground vascular plant biomass, and reduce soil carbon and nutrient pools (Christiansen et al., 2018). These changes can have cascading effects on ecosystem structure and function, potentially altering carbon and nutrient cycling processes. Additionally, reduced snow cover and earlier snowmelt can lead to advanced spring phenology in plants and increased mortality or physical injury in some species, fundamentally changing the environment and affecting ecosystem resilience (Slatyer et al., 2021). 6 Case Studies and Regional Analysis 6.1 Analysis of snow cover dynamics in different temperate regions Snow cover dynamics significantly influence temperate ecosystems, affecting soil moisture, plant growth, and overall ecosystem productivity. In temperate China, changes in winter snow depth and snowmelt dates have been shown to impact vegetation gross primary production (GPP). Thicker snow cover and later snowmelt generally result in earlier start dates for the growing season (SGS) due to increased soil moisture, enhancing spring carbon uptake in water-limited areas (Chen et al., 2019). Conversely, in wetter regions, thicker snow cover can delay SGS, reducing spring GPP (Figure 2). In semi-arid regions of China, increased winter snowfall has been found to enhance soil moisture in early spring, stabilize plant community composition, and increase net ecosystem exchange of CO2 (NEE). In the High Arctic, natural variations in snow depth and snowmelt timing influence soil and plant nutrient status and vegetation composition. Areas with later snowmelt have wetter soils, higher pH, and higher nutrient concentrations in plant leaves, leading to distinct vegetation compositions compared to areas with earlier snowmeltm (Moriana-Armendariz et al., 2022). Similarly, in the Canadian Low Arctic, long-term deepened snow experiments have shown increased winter soil temperatures and enhanced growth of evergreen shrubs, although this also led to reduced soil carbon and nutrient pools (Blankinship et al., 2012). Figure 2 Study of early, middle, or late snowmelt sites of natural snowmelt (Adopted from Rixen et al., 2022) Image caption: The yellow dots indicate snow manipulation experiments, and the green triangles indicate studies conducted along natural snow gradients. The darkest to lightest blue represents ice, mountains, grasslands, oceans, coniferous forests and tundra (Adopted from Rixen et al., 2022)
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