Phenological Patterns of an Endangered Tree Species Syzygium caryophyllatum in Western Ghats, India: Implication for Conservation

Abstract

In order to understand the vegetative and reproductive phenological behaviour of Syzygium caryophyllatum, the knowledge of the factor influencing leaf flushing, maturation, leaf fall, flowering and fruiting of this tree species is required. The authors used field observations collected over 3 years (2012–2015) at Neeliyarkottam sacred grove, Kannur district, Western Ghats of Kerala, India, to characterize the relationship between phenological pattern and biotic and abiotic (climatic) factors. The relationship between phenological pattern of the selected species and abiotic variables such as precipitation and temperature exhibited significant variation among the species. Flowering begins from second week of March to till May with a peak in April followed by the fruiting. Hand pollination tests indicated that most of the fruits were developed through xenogamous pollination. The breeding test results indicated S. caryophyllatum is self-incompatible and out-crossing is fertile. The foraging activities of some common pollinators on S. caryophyllatum flowers were also studied. The main flower visitors and foragers include honey bees, different varieties of butterflies, wasps, carpenter bees, small flies, bugs and ants. The flowering and fruiting exclusively occur in the dry season and are followed by germination and establishment of seedlings during the subsequent rainy season. The authors conclude that the investigations on the reproductive phenology, floral biology, breeding systems and pollinator visitation are important due to population survival of the species and its evolutionary success.