[Simulated study on the effects of smoke on Sphagnum spore germination]

Moderate smoke could facilitate seed germination, but its effects on bryophyte spore germination is still unknown. Here, we analyzed the effects of smoke, capsule size and storage time on the spore germination of Sphagnum squarrosum and S. magellanicum, with the capsules of which being collected from two peatlands of the Changbai Mountains. The smoke solution prepared by burning peatland plants was combined with the capsules with different sizes (large, 2.10-2.50 mm in diameter; small, 1.50-1.90 mm in diameter) and storage time (old, being stored for 4.3 or 6.3 a; new, being stored for 0.3 a) to conduct a factorial experiment. The spores were soaked with smoke solution for different durations and then cultured for germination. The results showed that smoke solution affected spore germination. After 10 d cultivation, germination rate of spores soaking with smoke solution for all duration was increased by more than 5-fold, with the small spores having higher germination rate. After 21 d cultivation, the facilitative effect was only observed in moderate soaking (3 d), and spore size showed no effect on germination. Smoke solution could not increase the germination of spores from the capsules with long storage time (4.3 and 6.3 a). Our results indicated that moderate smoke solution soaking might accelerate germination of Sphagnum spores including small pores. In the ecosystems with casual fire disturbance such as peatlands, similar with its effects on the seed plants, smoke might play a key role in the regeneration and persistence of bryophyte population.