Biodiversity and natural regeneration of kaong(Arenga pinnata ((Wurmb)Merr)in the riparian ecosystem of upland Cavite [Philippines]

The biodiversity and the pattern of natural regeneration of kaong in Upland Cavite were assessed to determined the floristic composition, structure, range and distribution of kaong; and analyze its natural regeneration in a distributed environment. The one-year study was conducted in three attitudinal sampling sites along Labac River located at Barangay [village] Anuling Lejos 2, Mendez(Site A); Brgy. Kayquit 2, Indang (Site B); and Brgy. Tambo Malaki, Indang (Site C) all in Cavite. The floristic composition and natural regeneration of kaong were observed in three observation plots(30 m x 10 m).Community structure was analyzed using importance value and diversity indices. The number of kaong regenerates were statistically compared. Site A and B had almost the same number of species at 71 and 74, respectively, while Site C had the lowest at 49. The species with the highest Importance Value (IV) were bogos (Acalypha amantacea),alim (Melanolipses multiglandulosa) and tibig (Ficus nota) for site A; caimito(Chrysophyllum caimito),anubing( Artocarpus ovatus), and bignay (Antidesima burius)for sites B; and tibig, binunga (Macaranga tanaruis) and ipil-ipil (Leucaena leucocephala)for site C. As for family importance value, leading were Euphorbiaceae and moraceae.All the sites showed high species diversity but low eveness value. Two species (bogos and coffee) were presented in all plots across sites. Nineteen other species showed a wide range of attitudinal adoption. All sites were dominated by shrubs and small tree, indicating high level of disturbance particularly in sites A and B. Canopy gaps in these two sites allowed the proliferation of many species compresing the understory vegetation. Being relatively less disturbed, Site C had the most number of large trees, namely:tibig, pagsahingin (Canarium asperum), binunga and dita (Alstonia scholaris). The Number of kaong natural regeneration was statistically the same across sites and regardless of distance from the mother plants. It was drastically affected however by the presence of disturbance brought about by human intervention.