Reproductive phenology period of the five threatened species in Cibodas Botanic Gardens

Abstract

Agathis borneensis, Castanopsis argentea, Diospyros celebica, Merrillia caloxylon, and Saurauia bracteosa are some threatened species, which have been planted in Cibodas Botanic Gardens as a garden collection. As part of the plant conservation program, their vegetative and reproductive phenology knowledge is crucial to understand when to harvest the seeds used for further propagation and restoration. The study aimed to investigate the phenology phases of these species as well as the impact of microclimates. The study used a descriptive-quantitative analysis based on the records of the exploratory-inventory observation of flowering and fruiting phase data and microclimate circumstances in 2018. Except for precipitation, the data revealed that CBG’s microclimate was considerably less diversified. The results also described that A. borneensis has flowering and fruiting almost throughout the year. C. argentea flowers at the end of the year and then develop into fruit at the beginning of the next subsequent year. D. celebica is also a low-intensity flowering plant that bears fruit almost all year. S. bracteosa has a long period of flowering from May to the end of the year. And then it started to develop into fruits from July to the end of the year and continued to January of the following year. Unfortunately, M. caloxylon is not shown a reproductive stage throughout the year. According to the findings, reproductive phases prominently occur early and at the end of the year, along with the rainy season. It also implied the appropriate time for seed harvesting conducted during these periods.