Mangrove Woods Damage Based On Time of Water Absorption Rate of Woods

Abstract

Mangrove forest was a main ecosystem supporting lives in littoral and sea areas. A mangrove forest has various advantages, such as fish, shrimps, crabs, and woods for a number of household needs. Littoral people tend to use mangrove woods to construct boats. The woods used are taken from mangrove trees in their own surrounding since the mangrove woods are considered strong, hard, and durable. The woods damage in sea occurs because the woods structures are not good enough and the amount of the extractive substances contained inside the woods is small. So, the woods structures are easily attacked by sea borer animals, which cause woods damage. The present study of mangrove woods damage based on time of water absorption rate of woods was conducted in Tuada village, sub district of Jailolo, West Halmahera. The purpose of the study was to examine the rate of water absorption on each type of woods and the damage level on each wood. This study employed an experimental design. The experiment woods used in this study were Rhizophora apiculata, Bruguiera gymnorrhiza, Osbornia octodonta, and Xylocarpus moluccensis. The measurement was conducted by: (1) preparing several mangrove boards sizing length 250 cm, width 30 cm, and thickness 4 cm. The boards were immersed 1 m or 2 m depth for about 15 months. The distances between the sea side and the immersed boards were 30 m and 50 m. (2) the rate of water absorption of the immersed board was measured. The data obtained were analysed by using anova and followed by Duncan Multiple Range Test (DMRT). The findings of the study showed that the rate of water absorption on the X. moluccensis was 5,698/second, which was the fastest rate compared to the other wood types. The rate of water absorption on the R. apiculata and B. gymnorrhiza was about 16,523-24,418/second, which was considered as moderate rate, while the slowest rate was found in O. octodonta 90,668/second. The faster the water absorbed by the woods, the higher the woods damage, vice versa.