How fire history affects germination cues of three perennial grasses from the mountain steppes of Golestan National Park

Smoke and heat as germination cues are some of the most important drivers stimulating seed germination. However, the impact of germination factors from wildfire (i.e., smoke and heat) on the germination of species occurring in western Asia has rarely been investigated. We aimed to analyze the effects of different smoke and heat treatments on seed germination of three perennial grasses (Festuca valesiaca, Poa densa, and Stipa zalesskii) collected from two non-burned and burned environments of the mountain steppes in Golestan National Park, Iran. Seeds were germinated on filter paper following smoke (1:2000, 1:1000, and 1:500, v/v) or heat (50, 80, 100 degrees C) treatments. Results showed that the germination of study species was reduced by heat treatments, whereas no particular response was observed with the smoke treatments. Interestingly, the fire history influenced magnitude of effects of fire-related germination cues, leading to slightly lower germination for F. valesiaca and P. densa and higher germination for S. zalesskii. Our results indicate that fire-related germination cues have different impacts on these grassland species. The consideration of the fire history of specific sites on germination ecology seems important to understand the effects of fire on the plant communities.

Automated summary

This study analyzed the effects of smoke and heat on seed germination of three perennial grass species in the mountain steppes of Golestan National Park, Iran. Results showed that heat treatments reduced germination, while smoke treatments had no significant effect, and the fire history influenced the germination cues differently for each grass species. The study suggests that considering the fire history of specific sites is important to understand the effects of fire on plant communities.