Population dynamics of seed and seedlings of Albizia procera (Roxb.) in Mizoram, India

Seed production, dispersal, germination, and seedling establishment are critical life phases of a tree species. Understanding these processes is crucial to recognize species composition and directional change for ecosystem restoration. This study aimed to estimate seed production, dispersal, and fate of the seed population of A. procera (Roxb.) and evaluate its seedling growth performance in relation to microclimates under natural conditions. Seed production was estimated from 15 sampled trees for three years, while seed dispersal using circular sample plots and seed traps under mother trees. The mean seed production per tree was 145,352, 43,607, and 41,490 during year 2022, 2023, and 2024 respectively, and it significantly differed between years (F = 12.09, P < 0.0001) and among individual trees (F = 4.63, P < 0.0001) while correlated positively with tree traits. Additionally, the seed density decreases with increased distance from the mother trees. A majority of the seeds (55.02% in 2022, 54.25% in 2023 and 52.92 in 2024) fell under the mother tree, while seeds disappeared due to predation and other losses reached 56.60%, 48.00%, and 49.80%, respectively. Germination rate in natural conditions were moderate (39.00%, 47.90%, and 45.40% in 2022, 2023, and 2024, respectively), and less than half (46.07%) of the germinated seedlings survived after 14 months. Further, relative seedling growth rate was strongly influenced by soil temperature, moisture and relative humidity indicating their crucial role in successful establishment. The findings provide essential insights into the population dynamics of A. procera and can inform strategies for monitoring growth and restoring degraded lands.