JOURNAL OF NATURAL RESOURCES ›› 2019, Vol. 34 ›› Issue (12): 2569-2579.doi: 10.31497/zrzyxb.20191207

• Special Forum of "Wetland" • Previous Articles     Next Articles

Effect of hydrological characteristics on the recruitment of Suaeda salsa in coastal salt marshes

WANG Qing(), LUO Meng, QIU Dong-dong, XIE Tian, SHI Wei, CUI Bao-shan()   

  1. School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Beijing 100875, China
  • Received:2019-04-07 Revised:2019-07-10 Online:2019-12-28 Published:2019-12-28

Abstract:

Salt marshes are increasingly valued for their function of coastal protection. Affected by periodic tidal events, salt marshes are highly dynamic ecosystems, especially for the hydrological characteristics. The dynamic hydrological characteristics have significantly affected the recruitment of plant, resulting in a profound influence on the distribution of salt marsh plants. To reveal the effect of hydrological characteristics on plant recruitment in salt marshes, this study conducted a field experiment on a bare patch of Yellow River Delta coastal salt marshes. A typical tidal inundation gradient was set, by choosing six transects from a main tidal creek to high areas on a bare patch in mid to high salt marshes. And the measurement of hydrological and soil characteristics, seed emergence and seedling survival experiments were conducted on the tidal gradient. Our results showed that: (1) Elevation, tidal hydrodynamics, and the inundation gradient had significant effects along the gradient from the creek to the salt marsh: The elevation of sampling points increased with the distance from the creek; on the temporal scale, there were wet and dry periods of hydrological process, the inundation frequency, water table and cumulative inundation period were lower during November to April, and they started to increase since May; on the spatial scale, the inundation frequency and cumulative inundation period decreased with the increase of elevation, and became stable after the average high water level; the relationship between the maximum water depth and elevation was revealed as a quadratic curve, and the maximum water depth reached the highest values in the elevation of 0.9 to 1.1 m. (2) Soil salinity and moisture content were not correlated with the hydrological gradient, but their changing trends were significant: with the increase of the distance to the tidal creek, soil salinity was increasing, while soil moisture content was decreasing. (3) The captured Suaeda salsa seeds (by seed traps), seed emergence rate and survival rate decreased with the increase of the distance to the tidal creek, which revealed that the recruitment of Suaeda salsa was significantly affected by hydrological characteristics. At the dry end of hydrological gradient (the higher area), the lower inundation frequency went against the dispersal of Suaeda salsa seeds, seeds emergence and seedling growth, which reduced the recruitment success of Suaeda salsa.

Key words: coastal salt marsh, recruitment, tidal hydrological characteristic, Suaeda salsa, Yellow River Delta