The effect of distance planting of red mangrove (Rhizophoraapiculata) on Pulau Sembilan, PangkalanSusu District, Langkat Regency

Mangroves are a very important coastal resource for socio-economic development In addition, mangrove habitats contribute to complex food webs and energy transfer. This research was conducted in the mangrove forest area of Pulau Sembilan Village, Pangkalan Susu. This research activity was carried out for 3 months from October to December 2022. Observations in this study were carried out every two weeks. This study was based on a completely randomized design (CRD) with 5 treatments with 6 replications. The treatment in question is the spacing with P0 = 46 meters, P1 = 47 meters, P2 = 48 meters, P3 = 49 meters and P4 = 50 meters. From the research on the effect of plant spacing on Rhizophoraapiculata, the highest seedling height growth was obtained in the P0 treatment (40m spacing) with a value of 213.2 cm or average 35.5 cm. The highest increase in plant diameter was found in the P0 treatment with a value of 7.59mm or average 1.27 mm. The highest added value was found in treatment P2 with a value of 37.0 cm. The increase in leaf length is 55.4 cm which is found in the P4 treatment.