Mangrove Habitat Assessment in Lavezares Northern Samar

Mangrove resources of the Municipality of Lavezares, Northern Samar were estimated with a total aggregate area of 1,038.4274 hectares, the 53.12% of which are distributed along the coastal margins in mainland and 46.88% along islands of the municipality. The mangal forests comprised of 13 true mangrove species belonging to seven families, which was predominantly of Rhizophoraceae combined with significant populations of Sonneratia and Avicennia species. The mangrove density varies at different sampled sites ranging from the least density of 2,100 to the densest of 24,900 stems per hectare. Six of the 12 mangrove sites have predominantly matured trees, an indicator of primary growth and six were of secondary growth with an average regenerative capacity of 72.60% of its populations.

Bakauan bankau (Rhizophora stylosa) has the highest density of 840 trees per hectare with a relative density of 35 percent followed by Api-api (Avicennia officinales) with density of 507 trees per hectare with relative density of 21 percent. Other densities include Pagatpat (Sonneratia alba) with 453 trees per hectare and 19 percent relative density. Bakauan lalake (Rhizophora apiculata has the least density of 267 with relative density of 12 percent.

For purposes of determining the number of saplings/wildlings in the study area, the mangrove assessment team established 3 regenerative plots (1m x 1m) per quadrat.

The use of acquiring data on the number of saplings in mangrove assessment is to provide information whether the area could regenerate naturally or it needs to have interventions like assisted natural regeneration or reforestation.

Based on the findings, there were only 41 saplings/seedlings encountered in all quadrats during the assessment. It implies that the area is not capable of regenerating itself naturally. Intervention like assisted natural regeneration through enrichment planting is necessary.

Assisted natural regeneration is the human protection and preservation of natural tree seedlings in forested areas like mangroves and improvement of the percentage of desirable species or genotypes and increasing biodiversity in a forest by interplanting.