Plant diversity and structure of forest habitat types on Dinagat Island, Philippines

Logging, mining and land conversion together threaten Dinagat Island. Diversity and structure of forest habitat types were determined as basis for conservation and management. Identification of forest habitat types was based on habitat's physical characteristics. Six forest habitat types were identified covered by 432 native plant species classified into 87 families and 203 genera, 40 plant species were endemic to Dinagat Island. Of the 432 species, 58% recorded in lowland evergreen forest (LEF), 16% in upper montane, 15% in forest over limestone, 6% in lower montane forest (LMF), 4% in mangrove forest, and 1% in beach forest, with average species diversity of 3.32. Trees in LEF were bigger, taller and larger in basal area as compared with other habitat types. Dominant species was Xanthostemon verdugonianus Náves ex Fern.-Vill with importance value of 9.857%. Native plant species was an asset for the mineral resource industry for site rehabilitation and conservation.