Conservation attempt of critically endangered mangrove Lumnitzera littorea (Jack) Voigt in Madu Ganga Ramsar Site of Sri Lanka; stand composition and seed germination

Abstract

Considering the environmental and specific socioeconomic significance of the critically endangered mangrove Lumnitzera littorea, this study was conducted aiming the conservation of the species. The specific objectives were to define the diversity of the other mangrove species in association with the existing L. littorea plant population in the Madu Ganga wetland, Sri Lanka, to study its seed germination and identify the barriers for seed germination. The existing population of L. littorea is an aged population with low regeneration potential. Most of the seeds collected at the dispersal maturity were empty. A micro moth belonging to Family Gelechiidae was identified as the embryo predator. Although GA3 (Gibberellic acid) treatment and dry storage reduced the germination time, none of the seed treatments significantly improved the seed germination of L. littorea. Low seed germination observed was due to absence of embryo in mature seeds as a result of insect predation and physiological dormancy of seeds. Optimum GA3 concentration, duration of dry storage and potting medium with suitable salt concentration for seedlings should be optimized in future research.