Carbon and nitrogen inputs from litterfall in the soils of suburban forests of Voronezh city

Suburban forests play a crucial role in maintaining ecosystem functions and the biogeochemical cycling of elements within urban landscapes. The aim of the study was to assess the input of carbon and nitrogen from plant fall, their accumulation in litter and accumulation in soils of suburban forests of Voronezh. The studies were performed in old-growth pine and oak forests. It was found that during the summer-autumn season in oak forests twice as much carbon (12.70 t/ha) and five times more nitrogen (0.35 t/ha) than in pine forests (6.48 t C/ha and 0.06 t N/ha) is supplied. Nevertheless, element stocks in forest litter were highest in pine forests, reaching 13.70 t C/ha and 0.35 t N/ha, due to the low decomposition rate of coniferous litter. Finally, the total soil carbon stocks in the one-metre column of Gleyic Phaeozems (Arenic) of oak forests (118.2 t/ha) were significantly higher than in Someric Phaeozems (Arenic) of pine forests (65.6 t/ha). Comparative analysis revealed that the primary cause of these differences in forest soils was related to the litterfall quality and its decomposition rate across different forest types. The results highlight the leading role of forest vegetation in soil formation and carbon storage in forest soils in in the urban landscape.