Diversity, vegetation analysis and RCE inventory employed in assessing riverine channel of Malapatan, Sarangani Province, Philippines

Vegetation assemblage and distribution was assessed through plot-nested method across riparian habitat in Brgy. Lun Padidu, Malapatan, Sarangani, Philippines. A total of 1331 individuals were recorded and were classified into 56 genera and 61 species. Of the total species sampled, 79% (49) were shrubs/herbs. However, the most abundant species are grasses suggesting that riparian vegetation in the chosen study site was mainly made of grassland community. Cyperus brevifolius (pugo-pugo) was found to have the highest Importance Value (IV = 26.09%) followed by Eleusine indica (IV = 10.43%) and Sterculia sp. (IV = 8.78%). Most species sampled were Least Concerned (LC) or Not Evaluated (NE) according to IUCN 2013. However, the presence of two invasive species - Chromoelana indica (hagonoy) and Saccharum spontaneum (talahib) may potentially disrupt the native flora in the study area. Diversity index indicates that area 2 is the most diverse however Evenness (E) values show that area 3 being least diverse, has the highest evenness value (E = 0.65). As a whole, Riparian, Channel and Environmental (RCE) inventory values show that the river is in good condition (mean RCE = 154). Mean RCE value further indicated that Lun Padidu river was Class III stream. This classification of the stream was supported by the presence of only few tree stand and shrubs and the dominance of grass species.