Trees tend to develop thicker bark so as to adapt to the greater fire danger. Leaves tend to be smaller and thicker so as to limit surface area, which reduces desiccation. Thorns tend to develop, so as to inhibit herbivore consumption. Roots become longer, so as to reach lower water tables or aquifers. Evergreens become deciduous.
With animals, larger mammals tend to occur: trees are farther apart. Reproductive cycles will tend to be timed to rainy seasons. Migration patterns may develop, causing animals to move to wetter areas in the dry season.
Tropical dry forests are particularly attractive to humans and to the species they have domesticated. The forests are heavily logged, and converted to pasture and farmland. As a rule, they are becoming endangered.