Association study of various species of epiphyte fern with host tree in Srengseng city forest

Vegetation is formed by the presence and interaction of several species of plants, one of them is association. This study aims to analyze the types and levels of association among five epiphytic fern species and their host in Srengseng City Forest, Jakarta. The method used was a survey method with a purposive sampling technique. The data collected were the number of individuals of 5 epiphytic ferns, the number of individuals, and the species of host trees. Measurements of light intensity, air temperature, and humidity were also carried out as supporting data. The association type was identified using 2 x 2 contingency tables by comparing observation value (a) toward expectation value E (a). The association levels were identified using Jaccard Index and Dice Index. The results showed that association types between epiphytic ferns and host trees were 71.79% positively and 28.21% negatively. Research indicates that association levels of epiphytes fern with the host were variously from low to high. The highest association occurred between Drynaria quercifolia with Zapoteca tetragona and Pyrrosia piloselloides with Zapoteca tetragona. Factors affecting the occurrence of associations are environmental conditions such as light intensity, air temperature, and humidity.