Vegetation cover at the Maguntan mud volcano (Sakhalin Island, Russia): species composition and spatial distribution
Mud volcano vegetation is not well-studied even in comparison with that of geothermal areas. Mud volcanoes provide opportunities to study the formation of the spatial and species structure of vegetation cover in distinct conditions, showing the trends in vegetation succession. The mud fields of the Maguntan mud volcano (Sakhalin, Russia) are cool, not warm, and their mud fluids have high salinity and alkalinity. In the 20th century some local endemic taxa were found at this place: Artemisia limosa, Gentianella sugawarae, Primula sachalinensis and Deschampsia tzvelevii. I identified nine plant communities and analyzed floristic richness, vegetation cover and endemism rate using data from 185 1 m × 1 m quadrats. The salinity decreases with distance from the volcano's main eruptive center. The total plant cover, number of plant species, and floristic richness increase with the distance from the volcano's center. Endemic taxa including the local endemic grass species Deschampsia tzvelevii are located in young mud substrates. Detrended correspondence analysis showed that the plant communities are arranged along a stress gradient. The spatial distribution of plant communities may be interpreted via succession dynamics.