Question

Tropical deciduous trees shed their trees in the dry season. Give reasons.

Answer 1

To prevent excess loss of water via transpiration.
Tropical deciduous trees usually possess large, broad leaves. When water is plentiful, the trees take up water. The large leaves take up sunlight to photosynthesise food; the excess water is removed through the leaves i.e. it is transpired.
During dry seasons when water is scarce, it becomes a necessity to conserve water that's available. That's the reason leaves are shed off to limit transpiration.

Answer 2

I think it is the answer