Data analysis
Excel was used for data processing and SPSS 17 for related statistical analyses.

RESULTS

The effects on plant height increments

Under different light intensities, the plant height increments of the six plant species studied showed significant differences (P< 0.01; Figure 1). The K. obovata , A. marina , and R. stylosa seedlings had the largest plant height increment under the G1 treatment and showed a gradually decreasing trend with decreasing light intensity. The A. corniculatum , C. tagal , and B. sexangular seedlings had the largest plant height increment under the G2 treatment; the height increments initially increased and then decreased with decreasing light intensity. These results indicate that too high or too low light intensity can inhibit the increase of plant height.
Under different flooding times, the plant height increments among the six mangrove species were significantly different (P < 0.01); all of the increments first increased and then decreased. Specifically, the largest plant height increments of C. tagal andB. sexangular seedlings were observed under the T2 treatment, while the other four species showed the largest plant height increments under the T3 treatment.
Under different seawater salinities, the plant height increments of the six mangrove species were significantly different (P < 0.01). The plant height increments of K. obovata , C. tagal , andB. sexangula seedlings showed a gradually decreasing trend, with the largest increments under S1 treatment. The plant height increments of A. marina , A. corniculatum , and R. stylosaseedlings first increased and then decreased, with the largest values observed with the S2 treatment. These results indicate that too high or too low seawater salinity can inhibit plant height increments of the seedlings.