University of Jember Researchers Identify Prehistoric Tree Ferns in Ijen Geopark as Living Fossils of the Dinosaur Era
A team of researchers from the Biology Department at the Faculty of Mathematics and Natural Sciences (FMIPA), University of Jember (UNEJ), has successfully identified a significant population of prehistoric tree ferns within the Erek-erek Geoforest, located in the Ijen Geopark region of Banyuwangi, East Java. These botanical specimens, belonging to the genus Cyathea, represent a lineage of flora that has remained largely unchanged for approximately 65 million years, dating back to the late Cretaceous period and the dawn of the Paleogene era. The discovery highlights the unique ecological preservation of the Ijen highlands, where two specific species—Cyathea contaminans and Cyathea orientalis—continue to thrive in an environment that mirrors the Earth’s ancient past.
The identification of these "living fossils" serves as a major milestone for Indonesian biodiversity research. Led by Professor Hari Sulistyowati, a seasoned researcher who has focused on the Ijen Geopark ecosystem since 2020, the team documented numerous specimens reaching heights of 6 to 10 meters. These towering ferns, often referred to locally as "paku tiang" or pillar ferns, are notable for their trunk-like stems and expansive fronds, which create a prehistoric aesthetic reminiscent of the landscapes inhabited by dinosaurs. The presence of such large and healthy populations suggests that the Erek-erek Geoforest acts as a critical refugium for species that have vanished or become rare in other parts of the world.
The Botanical Significance of the Cyathea Genus
The genus Cyathea belongs to the family Cyatheaceae, a group of tree ferns that first appeared in the fossil record during the Jurassic period, roughly 145 to 200 million years ago. However, the specific lineage identified in Banyuwangi is traced back 65 million years, a period marked by the mass extinction of the dinosaurs and the subsequent rise of mammalian life. While many plant species underwent radical evolutionary changes or succumbed to shifting climates, the Cyathea tree ferns maintained a stable morphology.
Cyathea contaminans and Cyathea orientalis are characterized by their robust, woody trunks, which are actually a dense mass of adventitious roots surrounding a central stem. Unlike modern flowering trees, these ferns do not produce wood in the traditional sense; instead, their structural integrity is maintained by these hardened root structures. The researchers at FMIPA UNEJ are currently conducting in-depth morphological analyses to better understand the resilience of these species. This includes studying the scales on the stipes (leaf stalks), the intricate patterns of the fronds, and the structure of the spores used for reproduction.
Geological Protection and the Role of Mount Rante
One of the most intriguing aspects of the discovery is the specific location where these ferns are found. The Erek-erek Geoforest is situated at an elevation of 1,600 to 1,700 meters above sea level. This high-altitude environment provides the cool temperatures and constant moisture required for tree ferns to flourish. However, elevation alone does not explain why this particular pocket of forest has remained so pristine.
Professor Hari Sulistyowati posits that the local topography played a defensive role in the survival of these prehistoric plants. The Erek-erek region is shielded by the massive landform of Mount Rante. This geological barrier likely acted as a buffer during the cataclysmic eruptions of the "Ancient Ijen" (Ijen Purba) volcano thousands of years ago. While surrounding areas were devastated by pyroclastic flows and thick volcanic ash, the specific orientation of Mount Rante may have diverted the destructive forces, allowing the Erek-erek Geoforest to remain an island of stability. This "protection effect" has resulted in a microclimate that has been preserved for millennia, characterized by high humidity, a dense forest canopy, and a reliable water supply from mountain springs.
Chronology of Research in the Ijen Geopark
The identification of these prehistoric ferns is the result of a multi-year academic endeavor. Professor Hari’s involvement in the Ijen Geopark began in 2020, shortly after the region gained significant attention for its geological and biological diversity. The initial phases of the research focused on general biodiversity mapping, identifying the various strata of flora from the foothills to the crater rim.
By 2022 and 2023, the focus shifted toward the Erek-erek Geoforest, a site noted for its "enchanted" atmosphere and dense vegetation. During field expeditions, the research team was struck by the sheer scale of the tree ferns, which stood in stark contrast to the smaller fern species typically found in disturbed or younger forests. The team spent months collecting samples, measuring tree heights, and documenting the environmental conditions—such as soil pH and light intensity—under the canopy. The official announcement of the prehistoric identification in April 2024 follows a rigorous verification process where the UNEJ team compared their findings with global paleobotanical records.
Environmental Conditions Favoring Megafauna Flora
The growth of Cyathea to heights of 10 meters is an indicator of an exceptionally healthy ecosystem. In many parts of Southeast Asia, tree ferns are threatened by habitat loss, illegal harvesting for ornamental use, or climate fluctuations. The Erek-erek Geoforest, however, offers a "Goldilocks" environment for these giants.
The humidity in the area remains consistently high due to the frequent mist and cloud cover common at 1,600 meters. This moisture is vital because ferns reproduce via spores that require water to move and fertilize. Furthermore, the dense canopy of the surrounding primary forest prevents the soil from drying out and protects the young ferns from direct, scorching sunlight. The abundance of water sources, combined with the nutrient-rich volcanic soil that has weathered over centuries, provides the perfect substrate for these prehistoric plants to maintain their slow but steady growth.
Scientific and Educational Implications
The ongoing research by the FMIPA UNEJ team is not merely an exercise in classification. It has significant implications for our understanding of evolutionary biology and climate resilience. Because these tree ferns have survived since the era of the dinosaurs, they carry genetic blueprints that have withstood various global climate shifts, including ice ages and periods of extreme warming.
The researchers are currently focused on four primary areas of study:
- Stem Morphology: Analyzing how the "pillar" structure supports such great heights without the presence of true secondary xylem (wood).
- Scale and Sorus Patterns: Using microscopic scales to differentiate between subspecies and understand their protective mechanisms against pests and UV radiation.
- Spore Analysis: Investigating the reproductive efficiency of these ancient plants in a modern, changing climate.
- Genetic Mapping: Comparing the DNA of the Ijen Cyathea with other populations in Australasia to track evolutionary migration.
Professor Hari noted that entering the Erek-erek Geoforest felt like stepping into a "dinosaur era" forest. This sentiment is echoed by the scientific community, which views the Ijen Geopark as a natural laboratory for studying the history of life on Earth.
Institutional Support and the Path Forward
The discovery has prompted a call for increased conservation efforts from both the academic community and the Banyuwangi local government. As part of the UNESCO Global Geopark network, Ijen is mandated to protect not only its geological features (like the blue fire and acidic lake) but also its biological heritage.
Officials from the University of Jember have expressed their commitment to supporting the FMIPA team with advanced laboratory equipment and funding for further expeditions. There is a growing consensus that the Erek-erek Geoforest should be designated as a high-priority conservation zone, limiting tourist access to specific trails to prevent the degradation of the delicate fern undergrowth.
Logically, the Ijen Geopark Management Board (BPP Geopark Ijen) is expected to integrate these findings into their educational outreach programs. By highlighting the "Living Fossils of Erek-erek," the geopark can attract researchers and eco-tourists interested in paleobotany, thereby boosting the local economy while fostering a culture of environmental stewardship.
Broad Impact and Global Relevance
The identification of Cyathea contaminans and Cyathea orientalis in East Java contributes to the global database of ancient flora. In an era where biodiversity is declining at an unprecedented rate due to human activity, finding a thriving population of 65-million-year-old species provides a glimmer of hope. It demonstrates that when ecosystems are left undisturbed and are shielded by natural geological barriers, life can persist across geological epochs.
Furthermore, these tree ferns play a vital role in the current ecosystem. They provide habitats for various epiphytes, mosses, and insects, forming a complex web of life that centers around their towering trunks. Their ability to sequester carbon and maintain soil stability on steep mountain slopes also makes them essential players in the local fight against climate change and erosion.
As the University of Jember continues its work, the world watches a small corner of Banyuwangi where the past and present coexist. The prehistoric ferns of Erek-erek are more than just plants; they are silent witnesses to the Earth’s long and tumultuous history, standing tall as a testament to the resilience of nature. The research conducted by Professor Hari and her team ensures that these giants will be understood, respected, and protected for generations to come.
