Vegetative and floral phenology of the mangrove, Ceriops tagal, with observations on the reproductive behaviour of Lumnitzera racemosa, in the Mgeni Estuary

Abstract

Phenological observations were conducted on Ceriops tagal Perr. C.B. Robinson (vegetative and floral) and Lumnitzera racemosa Willd. (floral) in the Mgeni Estuary. Leaf emergence in C. tagal was unimodal with high initial values in early summer (December), followed by decreasing numbers of leaves for the remainder of the summer, with the last leaves making their appearance in June/July. Leaf abscision showed high values in August/September but, with the exception of smaller peaks in April, produced no other consistent trends, Leaf/shoot ratios revealed an undulating pattern with high values in summer and decreasing values in the cooler months. Mean longevity of leaves marked in the first two years of the study was approximately 30 and 32 months respectively, It was not possible to follow reproductive behaviour in C, tagal. In L. racemosa a period of 3–4 months was required for development from flowers to the abscission of propagules. The significance of these results for litter production is discussed.