Population Dynamics of Mistletoes: Case Study on Golden Shower (Cassia fistula L.) in Purwodadi Botanic Garden, Indonesia

Background: There were about 1600 species of mistletoes throughout the world except Antarctica. Loranthaceae is the most dominant family and has the most species of mistletoe in tropical zones.

Aims: The aim of the study is to document the population distribution and dynamic of mistletoe species within this study site and to uncover their diversity in C. fistula in Purwodadi Botanic Garden, Indonesia.

Place and Duration of Study: Research was conducted in Purwodadi Botanic Garden during 2012- 2019.

Methodology: An explorative and descriptive study design was adopted. Data of mistletoes species and hosts, number of parasites, plant height, and stem diameter at 120 cm of DBH was collected by direct observation in determined blocks, where the mistletoes and C. fistula were found. Binocular was used to observe and count the mistletoes on the hosts. Infested host prevalence was counted by the proportion of the number of the infested host by mistletoes and the total number of hosts, while parasite density shows the proportion of parasite number (individual) and the total number of hosts.

Results: The population of mistletoe Dendrophthoe pentandra and Viscum articulatum in Cassia fistula varied by year and environment of habitat. The density of D. pentandra and V. articulatum has increased since 2012 and reached the highest density in 2015. The density of D. pentandra in the blocks differs significantly. V. articulatum is a hyperparasite mistletoe only found as a parasite on D. pentandara in C. fistula.

Conclusion: There were two mistletoes parasitized Cassia fistula in Purwodadi Botanic Garden during 2012-2019, i.e. Dendrophthoe pentandra and Viscum articulatum. The infestation and density of mistletoes on their hosts are dynamic in a community. The parasite density tend to increase from 2012 until 2015 and then decline to the lowest in 2019. The highest declining population due to mortality of mistletoes occurred in 2019 after 2015.