The relationship between standing vegetation and the soil seed bank along the shores of Lake Taihu, China

Abstract

Understanding the basic characteristics of wetland seed banks and the distribution of those seeds is fundamental to providing a theoretical basis for vegetation restoration and wetland management. This study explored the relationship between standing vegetation and the soil seed bank representing four vegetation cover types on the shoreline of Lake Taihu (China) using a seed germination method. The vegetation cover types consisted of the fleabane lakeshore zone (Zone A), bush and grass lakeshore zone (Zone B), crop lakeshore zone (Zone C), and natural reed lakeshore zone (Zone D). The viability of the seeds of all species found during a survey of standing vegetation in the summer of 2010 was assessed using greenhouse germination trials. The fleabane, bush and grass, crop, and natural reed lakeshore zones had 4, 16, 8, and 6 species from the seed bank, respectively. Sorensen similarity coefficients resulting from comparisons of the species found in the seed bank and in the standing vegetation of those same four habitats were 0.250, 0.333, 0.143, and 0.154, respectively. Low similarity levels between standing vegetation and the seed banks indicate that we should increase work on wetland protection and management because of its potentially low recovery ability. Seed density was significantly lower in Zone B (4933±1683 number/m2) than in the other zones (Zone A: 1160±502 number/m2; Zone C: 1360±587 number/m2; and Zone D: 1200±961 number/m2. The vertical distribution of seeds in the seed bank at the four zones showed a significant decreasing trend with increasing soil depth. The reserves of seeds in the topsoil seed bank accounted for 64.10%, 60.00%, 56.86%, and 68.89% of the entire seed bank in Zones A, B, C, and D, respectively. This research can promote to instruct and inform management practices in wetland protection, wetland management, and restoration and reconstruction in damaged wetlands.