Population size can be limited by many factors, in fact anything you can think of. Birth rate is the number of births per 1000 people per year. It is affected by many factors such as the ability to receive quality health care, the use and availability of contraceptives, governmental policies, economic growth, education, social and cultural views, and the use of abortion. If the factors are positively applied and individuals are more fertile and reproduce quickly, then the population increases.
Announcing incentives to promote late age marriage, and pledging to have one child, failure to which fines are imposed, as the case in china. Thier control program relies on education and public campaign. Death rate number of deaths per 1000 people per year. Death is caused by the lack of availability of food and water, lack of education, disease, lack of medical care, suicide, car accidents, crime and war. Deaths decrease the population. People entering (Immigration) a country for various pull factors like incentives for immigration, education, social and economic factors increases the population of country they move to.
This leads to suburbs sprawling encroaching forest land, wet land, agricultural land and portions of wildlife habitant. People leaving a country (Emigration) for various push factors including natural hazard like earth quakes, seeking better education opportunities, political instability, war, and hostile weather force people out from a region.
References. Ehrlich Paul R. ; Ehrlich Anne H; Olden, John P. Population and Environment Resources, 3rd Edition . San Francosco: 1977.