Stand structure and diversity of restored mangroves at abandoned pond in eastern coast of North Sumatra

Abstract

Mangrove forests are one of the coastal wetland ecosystems and productive that functions as a buffer of life. However, in the last few decades, mangrove forests continue to be degraded or lost due to various human activities, especially the conversion of mangroves into ponds. Mangrove restoration on abandoned pond land has been carried out in recent years in eastern coast of North Sumatra. This study aimed to determine the diversity and structure of mangrove vegetation resulting from restoration on ex-pond lands on the eastern coast of North Sumatra. A total of 30 sample plots, each measuring 10m x 10 m, have been built at each age of stands from 5 years-old to 9 years-old and secondary forests. All trees with diameter (DBH) ≥ 2 cm in the sample plot were identified, measured DBH and height. The restored mangroves on the eastern coast of North Sumatra have high regeneration although the diversity was lower than secondary mangroves. A number of mangrove tree species were found growing in restored mangrove even though they were not planted. Therefore, the mangrove restorations have good impact on mangrove conservation. Some efforts to maintain mangrove forests from restoration and secondary forests need to be considered in order to avoid various disturbances.