Short-Term Changes of Vegetation and Soil Properties in Scots Pine (Pinus sylvestris L.) Plantations in Northern Mongolia

This study looked at the impact of planting year differences on vegetation and soil parameters in Pinus sylvestris plantation forests in northern Mongolia. Tujiin nars region has three study sites: 18- to 20-year-old plantation forests planted in 2003, 2004, and 2005, as well as natural regeneration stand, natural forest, and steppe area. Three plots with distinct plantation stand types were constructed at each location to investigate changes in vegetation and soil attributes. Species richness, total coverage, and biomass accumulation were significantly higher in the oldest plantation (2003). This is consistent with the results, where BBS (2003 plantation) had the highest species richness (32 species), plant coverage (58.5%), and above-ground biomass (1159.6 g m2). Soil pH across plantations, with steppe and forest edge soils being alkaline and plantation soils slightly acidic. This matches the results, where soil pH ranged from 6.52 to 7.41, with plantations being slightly acidic. Available nitrogen (3.16 mg kg-1), soil organic carbon (10.1 g kg-1), and carbon stock (9.16 Mg ha-1) were higher in top soil and decreased by depth of profile and differed in plantations by year-of-planting. Furthermore, the change in understory vegetation was significantly correlated with soil moisture, fertility, and species composition was driven by over story density and crown parameters.