Ironwood

An important export of the Emerald Woods region of the Timara Empire are the rare Ironwood trees that are important for the construction of large buildings and ships for the empire.
Ironwood as the name suggests is as tough and hard as iron and many druids use this wood in place of metal in the construction of their armor and staffs as a well-worked piece of ironwood is as storng as platemail. Collecting this material is extremely time-consuming and dangerous as it steel tools that are used on these send sparks and can cause raging fires throughout an entire lumbar yard. 
The Emerald Woods sends this material to the great ship building cities along the Endless Ocean and is important to the region for in exhange for the wood they bring in large food supplies to feed to both the foundaries within the captured dwarven cities and throughout the Emerald Woods as very little land has been cleared away for agriculture. 
Ironwood grows more abundantly deeper into the woods but the groves of Ironwood are often guarded by dangerous woodland beasts, and even the occasional druid that deter all but the most determined from collecting this precious material. The wood itself makes a ship more resistant to the weapons found on other ships of balitias and arrows and Ironwood ships are less likely to be set on fire as well. 
While the Emerald Woods does provide normal lumber in addition to Ironwood, this one of the major exports that guarantees the protection of the Empire's Dragon Flights from other foregin forces that wish to take the woods over for themselves. Ironwood is also valuable to Spellcasters as well as the material is perfect for creating wands, staffs, rods, and in casting other spells making even a branch of ironwood extremly valuable.