Observe the succession process in natural systems and how water is the limiting factor to what types of plant communities will grow on a particular site.

• Succession is the process of change within a natural plant community whereby layering and diversity increases over time.

• Water is the limiting factor to the succession process. So, when water availability is at a minimum, the plant community will not develop past the first succession.

• Plants within the heath/tundra community are adapted to full sun, low soil fertility and low water availability.

• At the other end of the succession process is rainforest where water availability is at its maximum. All plants within a rainforest community are adapted to shade, high soil fertility and high available moisture.

• Sun intensity is another growth factor needed by plants. Rainforests, with the highest level of diversity and layering, will develop in tropical areas where sun intensity is at a maximum but rainfall still exceeds evaporation rates.

• If moisture levels are below minimal water availability then a desert will result. A sandy desert is due to excessive evaporation and an ice desert is due to excessive freezing. If moisture levels are above maximum availability then a wetland system or swampy meadow will result.

• Whenever a natural system is disturbed, the succession process needs to recur.

• Any attempt to replant rainforest species in a disturbed area will prove to be unsuccessful. You would need to go back in the succession process and select plants that are appropriate for the current conditions. As the newly established plant community develops in both diversity and layering, it will facilitate the increase in soil moisture and fertility that will eventually enable the rainforest community to reestablish itself.