Yakal (Shorea astylosa): The Enduring Strength of Philippine Forests

 As a forestry graduate and environmentalist, I’ve long admired our country’s native hardwood species, especially the Yakal tree, scientifically known as Shorea astylosa. This towering giant is more than just timber—it's a living testament to the richness of our biodiversity and a symbol of resilience rooted deep in our tropical forests.

During my college years, I had the rare opportunity to conduct hands-on research on Dipterocarps at the DENR Experimental Research Station in Bislig City. It was there that I observed and assisted in the clonal propagation of Dipterocarpaceae species, including Yakal. We used Indole-3 Butyric Acid (IBA) as a rooting hormone to enhance root development in stem cuttings. This process deepened my appreciation for how delicate, technical, and vital native tree propagation is—especially for species that are difficult to grow from seed or are becoming increasingly rare in the wild.

🌿 Botanical Profile and Classification

Yakal belongs to the Dipterocarpaceae family, known for producing some of the finest tropical hardwoods in Asia. Here's its scientific breakdown:

• Kingdom: Plantae

• Family: Dipterocarpaceae

• Genus: Shorea

• Species: astylosa

Endemic to the Philippines, Yakal is found nowhere else in the world. This alone makes its conservation a national duty.

🌱 Morphological Description and Growth Habit

Yakal is a large tree that can reach up to 30 meters in height. It has a straight, cylindrical trunk with a rough brown bark. The leaves are leathery and lanceolate, dark green on top and slightly hairy underneath. It bears yellowish flowers in small clusters, and its fruits are winged nuts dispersed by wind—a key trait of Dipterocarps.

In the wild, Yakal grows best in primary lowland forests, thriving at elevations up to 700 meters. It prefers deep, well-drained soils and undisturbed environments, which is why it’s often found in old-growth forests.

🌧️ Environmental Tolerance

Yakal thrives in humid tropical climates with high annual rainfall and moderate shade. It is not a pioneer species, meaning it doesn't regenerate quickly in open fields. However, with proper propagation methods like the one I observed in Bislig—IBA-assisted clonal propagation—we can enhance its chances of survival and restore it to our reforestation projects.

This tree also plays a vital role in soil stabilization, watershed health, and biodiversity support. Its strong roots help prevent erosion, especially in sloped and riverine areas.

🛠️ Economic Uses and Traditional Significance

The heartwood of Yakal is extremely hard, heavy, and yellowish brown, with outstanding resistance to decay, termites, and marine borers. Its applications include:

• Heavy construction (bridges, piers, docks)

• Mining support beams

• Railroad ties

• Shipbuilding and traditional fishing boats

• High-end flooring, beams, and structural components

Despite its limited use in folk medicine, Yakal is culturally significant—representing strength, endurance, and authenticity. It’s a species we’ve relied on for centuries.

📏 Growth and Propagation

One of the biggest challenges in Yakal conservation is its slow natural growth rate and the short viability of its seeds. That’s why clonal propagation using hormones like Indole-3 Butyric Acid is so valuable. During our experiments, I saw how stem cuttings, when treated properly, could successfully root and produce healthy seedlings—something not easily achieved with traditional sowing.

This propagation method, though resource-intensive, is a game-changer in restoring endangered native hardwoods like Yakal.

🌍 Ecological Role

Yakal’s ecological importance includes:

• Providing habitat for native wildlife

• Maintaining biodiversity in forest canopies

• Supporting watershed stability

• Contributing to climate regulation through carbon sequestration

In reforestation, it serves as a climax species—a long-living tree that signifies a mature, healthy forest system.

⚠️ Threats to Yakal

Yakal is now classified as Endangered due to:

• Illegal logging

• Habitat loss from agriculture and development

• Overharvesting for its premium hardwood

• Poor regeneration in the wild

Despite being legally protected, many Yakal trees are still harvested illegally, especially in remote areas.

📜 Philippine Laws Protecting Yakal

1. Republic Act No. 9147 (Wildlife Resources Conservation and Protection Act)

   • Yakal is classified as a threatened species, and cutting, gathering, or transporting it without a permit is punishable by law.

2. Presidential Decree No. 705 (Revised Forestry Code)

   • Regulates the harvesting and use of forest resources and promotes sustainable forestry practices for protected species like Yakal.

3. DENR Administrative Order No. 2017-11

   • Lists Yakal as a priority species for conservation, encouraging both in situ (in natural habitat) and ex situ (in nurseries and botanical gardens) conservation programs.

4. Local Ordinances

   • Some LGUs have declared mature Yakal trees as heritage trees, protecting them from felling and promoting eco-tourism and education.

💡 Final Reflection: More Than Just Timber

For me, Yakal is not just a tree. It’s a living legacy of our ecological wealth. My experience in Bislig City, working directly with its clonal propagation, gave me a firsthand glimpse of both its fragility and its strength. It reminded me that science, community involvement, and environmental awareness must go hand in hand.

Let’s not wait until Yakal exists only in textbooks and museums. Let’s preserve it now—for our forests, for our people, and for future generations.

✅ What We Can Do

• Support native tree planting efforts, especially those that include Yakal.

• Advocate for strong enforcement of forestry laws in our barangays and municipalities.

• Educate youth about the importance of Dipterocarps in our natural heritage.

• Document and report any mature Yakal trees in your locality for registration and protection.

• Share stories like this to inspire others to act.