Consider how the Big-leaved Acacia before you stands as a testament to Thailand’s evolving landscape. This isn’t just any tree. It’s a krathin-thepha a Big-leaved Acacia. Once upon a time around 1900 Mr. H. Slade the first Director-General of the Royal Forest Department recognized its potential.
Mr. Slade took a chance planting this species. He brought it from Burma and planted it at the Chiang Mai Forestry Office. Later he planted them on Bangkok roads. This act forever changed Thailand’s environment. The Big-leaved Acacia became a familiar sight. You may have seen it on roadsides or near temples.
But why this tree? The Big-leaved Acacia is easy to grow. It offers generous shade because its canopy spreads well. This made it ideal for lining roads and providing respite from the sun.
In the past northern Thailand cultivated lac. So they imported the Big-leaved Acacia for this purpose. They did not aim to use this type of wood to be useful in the trade at all. It’s easy so there are no popular users in construction. At that time Thailand still had a lot of better quality wood.
Interestingly foreign markets have long desired acacia wood. Hong Kong ordered it directly from the Philippines. During World War II acacia trees in the Philippines often suffered shrapnel damage. Buyers then turned to Thailand.
Thai shell prices were low. Wood sold at a better price. Farmers changed their economic crops. Khrang farmers in northern Thailand cut down Big-leaved Acacia to sell as lumber. This reduced acacia cultivation in the north.
Even now little remains despite a rising demand for acacia wood. Carvers use it because of a teak shortage. Teak is expensive so manufacturers use Big-leaved Acacia. It is plentiful and cheaper than teak. The wood also has a beautiful color making it a great substitute for teak in the woodcarving industry.
Today the Big-leaved Acacia isn’t just a roadside tree. It is a valuable resource. From academic and research reports on acacia wood it is known that acacia can be used in many ways. Both as wood it is forage crops and improves soil conditions.
These trees enrich the soil. Big-leaved Acacia leaves have high nutritional value for plants. Especially nitrogen is important. Because it is a legume plant its use is not complicated. You can mix it with planting material. Or you can put other trees like mangoes and jackfruit. Put a pile of leaves at the base of the tree. Over time the leaves gradually decompose. The tree grows faster than usual.
Look closely at the bark of the Big-leaved Acacia. Older trees have rough fissured bark. It ranges from greyish-brown to dark brown. The inner bark is pale brown. The bole can be branchless for 15 meters. It can also be up to 90 cm in diameter.
Consider the flowers. They are tiny white or cream and grow in spikes. The pods are broad linear and coiled when ripe. They hold black shiny seeds. The seeds are arranged longitudinally and attached by a colorful funicle.
So next time you pass a Big-leaved Acacia remember its journey. It is a story of adaptation utility and unexpected value. It’s a reminder that even the most common tree has a story to tell.