Diversity of pteridophyte species as bioindicators of forest ecosystem quality in Taman Hutan Raya Raden Soerjo Batu, East Java

Pteridophyte diversity is used as a bioindicator of ecosystem quality due to its sensitivity to environmental changes. This research aims to analyze the diversity and distribution of pteridophytes in three types of forest vegetation namely closed forest, open forest, and post-fire forest, in Tahura Raden Soerjo, Batu, East Java. The research employed a transect line and plot survey method to collect data on species composition, ecological indices and observed environmental parameters. Community structure was analyzed using the Shannon–Wiener diversity index, Pielou's evenness index, and Simpson's dominance index. The relationship between species and environmental parameters was analyzed using Canonical Correspondence Analysis (CCA) and Pearson's correlation test, with a focus on light intensity, temperature, humidity, and soil pH. The results showed that the highest species diversity was found in closed forests, supported by stable microclimate conditions, high humidity, and low light intensity. The most abundant and widely distributed species in this vegetation type was Dryopteris adnata. In open forests, diversity was in the moderate to high category, with commonly found species such as Dryopteris wallichiana. Post-fire vegetation showed the lowest diversity and was dominated by disturbance-tolerant species such as Selliguea enervis. This research confirms the potential of pteridophytes as effective bioindicators for assessing the health of forest ecosystems. It supports their use in conservation strategies and the achievement of SDG 15 (Life on Land).