The non-living, physical factor is also a part of a niche as it influences the effect of the population and how they effect the resources and its enemies.

A system with high species diversity and low dominance is less productive but stable. A system with a low species diversity and high dominance is more productive but unstable.

When the stable community, which is not the climatic or edaphic climax for the given site, is maintained by man or his domestic animals, it is designated as disclimax or disturbance climax or anthropogenic sub climax.

The soil remains drier for most of the time of the year and becomes suitable for development of wet woodland. It is invaded by shrubs and trees such as willow, alders, poplus. These plants react upon the habitat by producing shade, lowering the water table by transpiration, building up the soil and accumulation of humus with associated microorganisms.

When the ammonia is converted back into inert nitrogen, the process is called as denitrification. Bacteria are involved in this process which takes place in anaerobic conditions. Pseudomonas and Clostridium are responsible for the step of denitrification.  

Autogenic succession is caused by changes in soil structure and composition.  It is commonly found where the established community in response to environmental conditions or other factors, changes its habitat, eventually destroying itself. It is a kind of self destruction which is triggered by the external factors.

The individual organisms in the climax ecosystem are replaced by other organisms of the same kind. Thus, maintaining species equilibrium. The life and growth here indicates the climatic types of an area.

Energy cannot be reused indefinitely, though matter circulates. Energy from the sun or the solar energy is converted by the photosynthetic producers into chemical energy in the form of carbohydrates in plants.

Predation is a biological interaction where a predator feeds on its prey (the organism that is attacked). Predators may or may not kill their prey prior to feeding on them, but the act of predation often results in the death of its prey and the eventual absorption of the prey's tissue through consumption. It is an oppositional relationship.

The intermediate trophic levels are filled with omnivorous species which feed on more than one trophic level and they cause the flow of energy through various food pathways from the basal species.

The relationship between a predator and its prey is perhaps one of the most evident and clearly visible in the natural world. The relationship simply means that one life form consumes another. Traditional examples of a predator and prey relationship include a fox and a rabbit or an owl and a mouse. This type of ecological relationship can also be applied to situations wherein the deer is the predator and the grass is the prey.

Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area. Interspecific competition has the potential to alter populations, communities and the evolution of interacting species.

In peripatric speciation, new species are formed in isolated, smaller peripheral populations that are prevented from exchanging genes with the main population. Genetic drift is often proposed to play a significant role in peripatric speciation.

Temporal resource partitioning occurs when two species eliminate direct competition by utilizing the same resource at different times. This can be on a daily scale.

A keystone species is a species whose addition to or loss from an ecosystem leads to major changes in abundance or occurrence of at least one other species. One example is the herbivourous weevil Euhrychiopsis lecontei and its suggested keystone effects on aquatic plant species diversity by foraging on nuisance Eurasian Watermilfoil.