Indian sandalwood is a tree species known for its sweet aromatic wood, scientifically named Santalum album. The tree lives as a hemiparasite (partially parasitic) in its native ecosystem. The biological uniqueness makes its existence heavily dependent on companion vegetation from the early stages of growth. The tree mainly inhabits lowland tropical forest ecosystems that experience a distinct dry season.
The Parasitic Lifeway on Host Tree Roots
The Indian sandalwood tree can grow to a height of 12 to 15 meters in its natural habitat. The tree exhibits a fairly resilient adaptability to its environment. Its trunk is capable of thriving across various land conditions, ranging from coastal areas up to an elevation of 1,800 meters above sea level.
Its root structure is equipped with a specialized organ called a haustorium, which functions to attach to the roots of other trees. The organ absorbs water and essential nutrients from the host tree so that the sandalwood tree can survive.
As a tree requiring partial shade when young, sandalwood gradually demands full sunlight upon reaching maturity. The shift in required light intensity makes the development process of wild seedlings highly dependent on the density of the forest canopy.
The dependency on host trees makes the cultivation process of sandalwood quite complex compared to other timber tree species. Without the presence of suitable companion vegetation, sandalwood seedlings face difficulties in growing and developing properly.
The Secret to the Luxurious Fragrance of Heartwood
The primary distinction of the tree lies within the inner part of the trunk, which is known as heartwood. The section of wood possesses physical characteristics that are moderately hard, yellow to brownish in appearance, and oily in texture.
The essential oil accumulated within the wood fibers provides high resistance against natural decay. The formation of the aromatic oil requires a natural process that takes decades to complete.
The fiber density and long-lasting fragrance make heartwood a favorite raw material for fine craftsmanship. Beyond its use for intricate carvings and religious ornaments, the wood is also processed into various functional items, such as jewelry boxes and picture frames.
The steam distillation process applied to the heartwood yields an extract known as sandalwood oil. The processed product serves as a high-value raw material in the cosmetics, perfumery, and aromatherapy industries. Its aroma profile tends to be sweet, woody, warm, and exceptionally long-lasting upon application. The natural compounds within it are frequently utilized to help relieve anxiety and stress.
The application of sandalwood oil in the health industry also includes leveraging its active medicinal properties. The oil contains antiseptic, anti-inflammatory, and antimicrobial properties that are beneficial for skin care. Its extract formulations are widely used in pharmaceutical products to treat inflammatory skin conditions, such as acne and psoriasis.
The Threat of Exploitation to Natural Populations
The natural population distribution of sandalwood encompasses regions in India, Sri Lanka, and the eastern area of Indonesia. In Indonesia, the presence of the tree is documented from the Nusa Tenggara Islands, Sulawesi, and Maluku, to the Aceh region.
The province of East Nusa Tenggara has historically been one of the most crucial natural habitats for the growth of the tree. However, harvesting rates that exceed its natural growth continue to put pressure on the remaining trees in the wild.
Massive logging over many years has rendered commercially sized trees increasingly scarce. Trees with a trunk girth exceeding 30 centimeters have even been declared commercially extinct in several natural forest areas. Its scarcity of mature stands triggers a sharp decline in the number of mother trees capable of producing high-quality seeds.
In 2019, the International Union for Conservation of Nature categorized Santalum album under the Vulnerable status due to population decline caused by illegal logging and overexploitation.
Reference: Arunkumar, A. N., Dhyani, A., & Joshi, G. (2019). Santalum album. The IUCN Red List of Threatened Species 2019, Article e.T31852A2807668. http://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T31852A2807668.en
