Q. What is the climax stage of an ecological succession?

The climax stage is the stage of an ecological succession in which the community of an ecosystem turn into stable and doesn't undergo significant changes. In the climax community practically all the ecological niches are explored and greater biodiversity is possible and in this stage the biomass, the photosynthesis rate and the cellular respiration reach their maximum levels and thus the net primary production (NPP = organic material made by the producers - organic material consumed in the cellular respiration of the producers) tends to zero. At the climax the volume of the oxygen released by photosynthesis is practically equal to the oxygen consumed by respiration (This is one more reason why it is wrong to say that the Amazon Rainforest, an ecosystem at climax stage, is "the lung" of the earth. Other reasons are: lungs are not producers of oxygen; the algae and cyanobacteria of the phytoplankton are the main producers of the molecular oxygen of the planet).