Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (10): 899-908.DOI: 10.17521/cjpe.2019.0154

• Research Articles • Previous Articles     Next Articles

Effects of soil-burial depths on the relationship between seed mass and seed emergence

WANG Zu-Xing,HE Wei-Ming()   

  1. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
  • Received:2019-06-24 Accepted:2019-09-05 Online:2019-10-20 Published:2020-02-24
  • Contact: HE Wei-Ming
  • Supported by:
    the National Key R&D Program of China(2017YFC1200102)


Aims Seed emergence is a key stage of plant life history and thus of important impacts on interspecific relationships and community composition. Increasing evidence has shown that seed mass determines (or strongly affects) seed emergence within a species, but it has seldom been tested across species at different depths of soil burial. Accordingly, the purpose of this study was to examine the influence of soil burial depths on the relationship between seed mass and seed emergence. Methods We performed a full-factorial experiment. Two factors included plant species (i.e. Achillea millefolium, Achnatherum sibiricum, Chenopodium glaucum, Centaurea maculosa, Medicago falcata, Poa pratensis, P. secunda, Solidago canadensis, Stipa bungeana and Vulpia octoflora) and soil burial depth (i.e. 0, 1, 2, 4 and 8 cm). Each combination was replicated five times, totaling 250 pots (10 species × 5 burial depths × 5 replicates). For each species, seed mass was determined prior to sowing at a given soil burial depth. We watered the pots and recorded seed emergence every day for 30 days. We determined the first date of seed emergence, and calculated the overall seed emergence, the tolerance to soil burial, and T50 (i.e. the number of days in the presence of 50% emergence). Seed mass and seed emergence were analyzed using an analysis of variance, and the relationships between two variables were tested using correlation analyses. Important findings We found that: (1) The optimum soil burial depth for seed emergence varied among the species, and for most of tested species this optimum depth ranged from 0 to 2 cm (i.e. shallow soil); six species had the maximum seed emergence at 1 cm soil burial depth, and no species had the maximum seed emergence at 4 or 8 cm. (2) There was a positive correlation between seed mass and the tolerance to soil burial across the 10 tested species, specifically, the tolerance to soil burial and the optimum depths increased with seed mass. (3) At deeper soil burial depths (i.e. 4 or 8 cm), there were significantly positive correlations among seed mass, seed emergence, and T50; in contrast, such correlations did not occur at shallower burial depths (i.e. 0, 1 or 2 cm).

Key words: soil burial depth, seed mass, seed emergence rate, emergence speed, tolerance to soil burial