Germination strategies of 20 alpine species with varying seed mass and light availability

Seed germination is a central component of plant life history. To investigate the proposed role of seed size on germination strategy in plant communities, a semifield experiment was conducted in alpine meadow of the Qinghai-Tibetan Plateau, China. Interspecies relationships of seed mass and seed germination characteristics were studied under semifield conditions with different light availability. Light availability and seed mass had significant effects on final germination percentage and time to germination for studied species. There was a significant negative correlation between the strength of light required for germination and seed mass. Fifteen study species (e.g. Ligularia przewalskii, Artemisia sieversiana Willd, Tripolium vulgare Ness. and Saussurea morifolia Chen) exhibited a synchronous germination strategy. Seeds from large-seeded species, such as Dracocephalum ruyschiana, Laniophlomis rotate (Benth.) and Salvia przewalskii Maxim., were less likely to require light for germination than those of small-seeded species, such as A. sieversiana Willd, Senecio diversipinnus Ling and Saussurea mongolica (Franch.). We propose that germination strategies of small-seeded species are well suited to unpredictable environmental variation in this alpine grassland community.