GLADKOVA G.A., SIBIRINA L.A., OMELKO A.M., ZHMERENETSKIY A.A., UKHVATKINA O.N., KUPRIN A.V.
Lesovedenie 2025; (5): 643-655
Studying the forest litterfall formation is a crucial stage in understanding the forest-soil system, as well as the characteristics of the global biogeochemical cycle in forest ecosystems. This study is aimed at assessing the seasonal dynamics and spatial intra-ecosystemic variations in mass and fraction composition of forest litterfall in undisturbed mixed broadleaved-Korean-pine forests of southern Sikhote-Alin (Primorsky Krai). The litterfall includes leaves, needles, branches, generative organs and other fractions, and it was collected on five permanent sample plots representing mixed-shrub - Korean pine forest with linden and birch (Betula costata Trautv.) since August of 2023 to August of 2024. Each sample plot had 10 litterfall traps measuring 0.5 m2. Average litterfall mass for this period was 4.74 ± 0.13 t ha-1. During the period since 1974 to 1991 similar ecosystems received 3.87-4.63 t ha-1 of litterfall annually. A slight increase in the litterfall quantity in recent times may be due to extremely warm and humid summer seasons in 2023 and 2024, as well as due to internal changes in the community's structure. Litterfall's fractions' composition varied significantly between the sample plots and reflected the stands' composition. The main fall of leaves and needles occurred in autumn (September-October). Summer litterfall consisted mostly of generative organs and the summer and spring litterfall of branches and bark. The most prominent difference between the 2023-2024 and 1974-1991 periods was an increase in the leaves proportion in the former, combined with a decrease in proportions of needles, branches and generative organs. The calculated phytomass of living components (needles, leaves and branches) was 4.7 ± 0.7; 2.5 ± 0.3 and 35.4 ± 0.9 t ha-1, respectively. The average mass of needles and leaves caught into the litterfall traps was 28 and 93% of the living fractions respectively. Wind and the ecosystems' position on slopes also play a significant role in deciding the spatial distribution of forest litterfall on sample plots.
