Summary

In this module, we introduced you to some of the basic ecosystem processes affecting the vegetation of tropical forests. We examined how light, nutrition and water play critical roles in enabling plants to survive and reproduce in the forest. We looked at how it is not possible to have ‘the best of all worlds’ – trade-offs are required between some traits. For example, dense, strong wood generally grows at a much slower rate than very light, easily broken wood. These functional traits are important in understanding the responses of plants to the environment.

We also looked at disturbances in forests. A variety of agents can cause disturbance, including cyclones, lightning, pathogens, humans and others. Many of these interact: a tree infected by a fungus that has caused heartrot will be susceptible to damage in a cyclone. We considered how pre-industrial humans have affected the structure and composition of tropical forests, and looked at how long this has been going on. Finally, we looked at the resulting patterns, both in space and time, seeing the forest as a dynamic mosaic of different-aged patches, all developing at different rates.