Litterfall release, vegetative, and reproductive phenology investigation of Heritiera fomes Buch-Ham in the Sundarbans mangrove forests, Bangladesh: relationship with environmental variables

Abstract The study of vegetative and reproductive phenology through litterfall collection of mangrove species is vital for mangrove management and restoration in climate change situation. This study was carried out to investigate vegetative and reproductive phenological pattern of Heritiera fomes using litterfall data in the Sundarbans, Bangladesh for a period of 24 months. Leaf and stipule litterfall released throughout the year with a distinct periodic pattern. Vegetative litterfall (981.9–1211.3 g/sq m/yr) contributed 59.3% of total litterfall (1791.1–1907.3 g/m/yr). The order of vegetative litterfall was leaf > branch > stipule. Peak flowering and mature fruit litterfall were noticed in April (1.52 times of mean monthly flower production) and July (1.56 times of mean monthly production), respectively. Analysis of variance (ANOVA) showed significant difference (p < 0.05) among monthly litterfall productions, whereas t-test showed no significant difference (p > 0.05) of litterfall production between two successive years during study periods. Vegetative and flower litterfall were significantly influenced by maximum wind speed, mean monthly temperature and day length. On the contrary, mature fruits were significantly correlated with rainfall.