Figure 1: Changes in the plant height increment of different mangrove species under various light intensities, seawater salinities, and flooding times. The K. obovata seedlings died under the S3 and S4 treatments, and no data are shown.
The effects on the biomass accumulation
Under different light intensities, the biomass accumulation of the six mangrove species showed significant differences (P < 0.01; Figure 2). The K. obovata , A. marina , and R. stylosa seedlings accumulated more biomass under the G1 treatment and showed a gradually decreasing trend with decreasing light intensity. TheA. corniculatum , C. tagal , and B. sexangulaseedlings exhibited larger biomass accumulation under the G2 treatment; they first increased and then decreased with the decrease of light intensity. These results demonstrate that too high or too low light intensity can inhibit the biomass accumulation of seedlings.
Under different flooding times, the biomass accumulations of the six mangrove species were significantly different (P < 0.01; Figure 2), all showing a trend of first increasing and then decreasing. The A. marina , A. corniculatum , and R. stylosa seedlings all had the largest biomass accumulation under the T3 treatment, while K. obovata , C. tagal , and B. sexangula seedlings had the largest biomass accumulation under the T2 treatment, indicating that too short or too long flooding time can inhibit the biomass accumulation of seedlings.
Under different seawater salinities, the biomass accumulations of the six species were significantly different (P < 0.01; Figure 2). The biomass accumulations of K. obovata , C. tagal , and B. sexangula seedlings all showed a gradually decreasing trend, with the largest biomass accumulation under the S1 treatment. The biomass accumulations of A. marina , A. corniculatum , and R. stylosa seedlings first increased and then decreased, with the largest biomass accumulation under the S2 treatment. These results indicate that too high or too low seawater salinity can inhibit the biomass accumulation of seedlings.