STRUCTURE AND COMPOSITION OF FLORAL AT MANGROVE FOREST IN PITAS SABAH MALAYSIA

Struktur dan Komposisi Bunga pada Hutan Mangrove di Pitas Sabah Malaysia

Abstrak

The aim of the study was to determined and record mangrove species composition and
diversity at Pitas mangrove forest, Sabah. Mangroves forest occurs in waterlogged, salty
soils of sheltered tropical and subtropical shores. It usually found along the coastlines
throughout the world, usually between 25º N longitude and 25º S latitude. This study was
conducted in Pitas district (N 06?43’, E 117?4’) which is located at the northern tip of
Sabah, Malaysia. Whereas, Pitas district has an approximately 38,564 ha of the mangrove
area. In this study, the mangrove location covered an area ranges from Malawali island
(N 07?2.023', E 117?16.883'), Tobo island (N 07?01.070', E 117?19.008'), Layak-layak
island (N 06?56.587', E 117?14.323'), Mapan-mapan (N 06?51.608', E 117?14.861'), and
Jambongan island (N 06?45.016', E 117?25.816'). The random sampling method was
done with simple plots sizes of 20m x 20m to determine the species’ biodiversity,
composition and structure. As a result, 13 mangrove species have been identified in all
study locations namely known as Sonneratia caseolaris, Ceriops tagal, Bruguiera
gymnorhiza, Rhizophora mucronata, Aegiceras corniculatum, Avicennia marina,
Rhizophora apiculata, Sonneratia alba, Bruguiera cylindrica, Lumnitzera littorea,
Pemphis acidula, Scyphiphora hydrophyllacea, and Scaevola taccada. The result shows
that the Shannon –Wiener biodiversity index (H’) at the island and disturbed mangrove
areas is less diverse (H’ below than 1.5) compared to the undisturbed mainland areas
with (H’=1.95). Sonneratia caseolaris is the dominant mangrove species in the island
with the highest value of Important Value Index (IVI) with 144.77% compared to all
species in the study location. These areas show the importance of ecological aspects
within the forest ecosystem. Therefore, the protection and conservation of this mangrove
in this area is a necessity.
Keywords: Mangrove, species composition, diversity, Important Value Index (IVI),
island, mainland, disturbed, Pitas Sabah