Species diversity and composition of mangroves in Tacloban City, Philippines

Abstract

This study reflects the present status of Tacloban City mangrove vegetation and would be useful for mangrove restoration program. Surveys of mangrove forests in Tacloban City were conducted from October to November 2017 in 12 selected sites. Quadrat method was used to assess the species composition and stand structure of the canopy layer, representing seaward, middle and landward zones. The mangrove forests in Tacloban City contain 23 mangrove species belonging to 12 families and 15 genera. Rhizophoraceae and Acanthaceae are the most dominating families. As per IUCN report, among the 23 species, 4 were recognized as threatened. These include the Endangered Camptostemon philippinensis, the Vulnerable Avicennia rumpiana and the Near Threatened Aegiceras floridum and Ceriops decandra. Rhizophora Apiculata is the most abundant species, followed by Sonneratia alba. Other abundant species are Avicennia officinalis, Avicennia marina and Rhizophora mucronata. The least abundant are Bruguiera gymnorrhiza, Camptostemon philippinensis and Xylocarpus granatum. The canopy layer is composed of small-sized trees with an average tree density of 1,678 per ha and stem density of 3,133 per ha. The average height and diameter are 6.15m and 8.95cm, respectively. Mangrove diversity is generally low. Shannon index of diversity value ranges from 0.762 to 1.132, with an average value of 0.914. Understory is characterized by few species of regenerants, low density and low species diversity.