Seedling composition and dynamics of a deciduous broad-leaved forest in the subtropical-temperate transitional zone of the Qinling Mountains, China

We investigated the species, quantity, germination, and mortality of woody seedlings in a 25 hm² broad-leaved deciduous forest plot in the Qinling Mountains of China from 2015 to 2019 and analyzed the species composition and dynamic characteristics of seedlings. Results identified 69 species belonging to 42 genera and 24 families, including a total of 11 408 seedlings (2015 to 2019). There was little change in species composition and dominant species composition in the plot, but species number decreased overall. Seedling numbers varied significantly among different tree species across years, including 17 species with more than 100 individuals (accounting for 56.28%) and 53 species with new seedlings. In total, there were 6280 recruited seedlings, 6929 dead seedlings, and 4469 new seedlings, accounting for 74.14% of the total number of recruited seedlings. The mortality of newly recruited seedlings was much higher than that of old seedlings. Peak seedling growth and mortality roughly occurred from May to July each year. The number of seedlings in the plot fluctuated steadily, and species regeneration was relatively stable.