Issues affecting Population Growth

Many factors naturally affect the growth patterns and final outcomes of population growth. The issues are so complex as to escape a reliable prediction and only a full understanding of the natural environment and all its complexities and application of Chaos theory will provide reliable predictions over time. The interconnectedness of all organisms within time and space make this a daunting and perhaps hapless quest.
However there are some less complex, perhaps obvious factors that affect population growth patterns and we will examine them below.

Density-dependent  factors

Intraspecific Competition - species members compete for the same resources of space, food mates etc.

Allelopathic inhibition - some plants mesquite, walnut, peach, secrete chemicals into the soil that inhibit plant growth
- many antibiotics are gleaned from bacteria that use the same (or analogue) chemicals to control the population of competitors for the same resources they are after.

Predation - high prey density favors the success of predators
- high density of predators favors prey in the long run

Allee effect - once some populations get below a certain size they will collapse due to lack of genetic variation (Florida Panthers) , inablity to engage in needed social facilitation (passenger pigeon), inabiltiy to find a mate (blue whale) 

Density independent factors
Climate Change> presently many changes are occurring due to this human induced phenomena > CO2, >temp ,> ecoinvadors > disease-
Limiting factors - environment lacks one needed requirement
Environmental Disruption >
Insecticides>bioamplification
Habitat loss> island effect
Gene Pollution>
Agriculture>
Urbanization>