Effects of dry storage and water submersion on seed germination of 21 herbaceous species indigenous to the Three Gorges Reservoir Region.

Regeneration using seed is an important measure for wetland vegetation restoration,and the germination requirements,especially responses to water submersion,are the fundamental information for selecting suitable species as seed sources.In order to select seed sources for vegetation restoration in the water fluctuation zone of the Three Gorges Reservoir Region (TGRR),we collected 21 herbaceous species indigenous to the riparian zone of TGRR,and set the germination rate of fresh seeds as control to compare with seeds stored at two different conditions:dry storage and water submersion with different water levels (0.5, 1.0, 2.0 m).Compared to the control, the 8 month dry storage enhanced the germination rate of 8 species (38.1% of total species number),decreased that of 12 species (57.1%),and didn’t have any impact on that of 1 species (4.8%).As for the water submersion treatment,germination rate of 76.2% species was decreased,and that of 14.3% species was increased and that of the rest 9.5% species was not affected compared to the control,indicating that the germination rate of most species was reduced by water submersion.However,there was no significant difference between germination rate of seeds under different water levels.The germination rate of Amaranthus paniculatus,Amaranthus viridis,Amaranthus sp. after dry storage,and Eclipta prostrata after water submerged were more than 50%.Furhermore,they were able to fulfill their life history over course of water recession, thus these four species should be prioritized for vegetation restoration via seed in this region.These findings have implications for the scheduling and management of restoration practices with seeds in the water fluctuation zone in TGRR.