Abstract: Soil burial depth is one of the key factors affecting the seed germination and seedling growth of wetland plants. In this paper, a laboratory simulation experiment was conducted to study the effects of soil burial depths (0, 5, 10, 15, 20, 25, and 30 mm) on the seed germination percentage (GP), germination speed (GS), shoot length (SL), and root length (RL) of Phragmites australis and Typha domingensis in the riparian wetlands along the downstream of Songhua River, Northeast China. The main objective of this study was to provide the technique and strategy for guiding vegetation restoration via sexual reproduction approaches for P. australis and T. domingensis along the downstream of Songhua River. Significant effects of soil burial depth on the GP and GS were observed for both P. australis and T. domingensis. The seed GP and GS of P. australis and T. domingensis varied with soil burial depth. The seed GP and GS of P. australis were higher when the soil burial depths 0 mm and 25 mm, while those of T. domingensis were higher when the soil burial depths were 0 mm and > 25 mm. From the viewpoints of SL and RL, the soil burial depths of < 10 mm were more beneficial to the survival and growth of P. australis and T. domingensis. At the same soil burial depths, the seeds of P. australis had stronger germination ability than those of T. domingensis.

Key words: meteorological parameters., evapotranspiration, eddy covariance method, Penman-Monteith model