Species composition, habitat structure and sedimentation in a Sonneratia caseolaris stand at the Lam River estuary, Vietnam

Abstract

This study aims to provide some information for development of silvofishery systems with a mangrove (S. caseolaris stand) for shrimp-culture ponds at the Lam River estuary, Vietnam. To achieve this objective, species composition, habitat structure and sedimentation effect in the S. caseolaris stand distribut- ing along the canal for shrimp culture were surveyed. The study reveals that the stand contains four species or more under the canopy; dominant under- story species are Aegiceras corniculatum, Cyperus malaccensis and Acanthus spp. (A. ilicifolius and A. ebracteatus). A. corniculatum was observed expanding its distribution area toward the low tidal zone. As a result, the habitat for seedlings/saplings of this species becomes significantly lower in land height than that of Acanthus spp. (ANOVA; p<0.05), but not different from that of S. caseolaris. Sedimentation rates of A. corniculatum and Acanthus sp. recorded were 13.2, 2.9 g m⁻² h⁻¹ and 13.0 4.4 g m⁻² h⁻¹, respectively. S. caseolaris sparsely grows with less developing of pneumatophore, which effectively traps sediment, at the early stage of succession. Considering reinforcement of sedimentation effect, especially right after restoration of the mangrove in the silvofishery systems, A. corniculatum and Acanthus spp. with S. caseolaris are recommendable to be introduced to the systems.