Wood has little place in the ‘concretized’ contemporary Indian architecture other than interiors and shuttering work etc. It however plays an important role in forming the basis of Indian temple and monastery architecture. When permanent structures in stone and in caves etc began to be built, the masonry of wood was replicated in the construction.
The replication was not a co-incidence. It was a deliberate attempt to maintain the sanctity of wood even in stone. A threshold in a temple built out of stone is not a structural requirement. It is necessarily a requirement in wooden masonry. In spite of that it is replicated in all ancient Hindu temples. Buddhist monasteries till date replicate wood in their column and pillars, thresholds, doorways, lintels and window frames etc in their construction. Ancient Buddhist caves like those at Karle follow similar principals.
The great Stupa at Saanchi has an intricately decorated torana which was very typical of a wooden torana. The entire stupa is circumambulated by a stone fence which is exactly like a wooden picket fence.
Why this religious adherence to wood? Probably because wood was one of the first materials of structural construction apart from stone and sun burnt bricks. It however was considered the most pure of the lot. Probably because it was natural and not man made like bricks. Also, it was a lot easier to use while constructing temporary, quick to erect shelters around shrines as compared to stone.