WHAT IS VEGETATIVE GROWTH? - SCIENCE - 2025

The vegetative growth is the change in population size caused by the interplay between birth rates and death. If the birth rate exceeds the death rate, then the population will increase. If the death rate exceeds the birth rate, then the population will decline.

Of the three factors (fertility, mortality and international migration) that determine the size of a country's population, those that determine natural or vegetative growth are the fertility or birth rate and the death rate.

The first stage of demographic change is the time when the birth rate and death rate fluctuate and are quite high. This is the period when the vegetative growth rate of the population is usually low.

The second stage of the transition is when the death rate begins to decline, while the birth rate remains more or less constant. This is the period when the population growth rate begins to increase and reaches its maximum.

In the third stage, the birth rate also begins to decline in response to the decline in the death rate. Finally, the fourth stage is when the birth rate and the death rate are quite close and the birth rate is close to the replacement level and fluctuates.

This is when the vegetative growth of the population stops or slows. Countries at this stage often tend to balance population size through immigration of some international migrant population.

Demographic equilibrium can often be achieved as a long-term goal when the birth rate of a population equals the death rate, that is, when the replacement level is met and the rate is stable.

Current world population

Currently, the world population is 7 billion and is expected to reach 10 billion in 2080 and then vegetative growth is expected to stabilize. The population has been growing exponentially in the past two centuries, going from just 0.75 billion in 1750 to 7 billion today.

Population growth peaked in the 1960s, when the natural increase in world population was 2.2%. Today, the natural increase is falling, but it is not expected to stabilize until 2100.

Population doubling time: Simply put, the population doubling time is the time it takes for the population to double.

-2% growth rate - population doubling time would be about 35 years.

-3% growth rate - the doubling time of the population would be approximately 24 years.

-4% growth rate - the doubling time of the population would be about 17 years.

Components of population change

• Life Expectancy - The average number of years that a person from a specific country is expected to live.
• Birth rate - Number of people (alive) born per 1000 inhabitants per year (usually per km2).
• Mortality rate: the number of people who die per 1000 inhabitants per year.
• Annual Population Change: It is when the accumulated change in the size of a population after natural change and migration has been taken into account.
• Calculation of population change: Population change = Birth rate ± Death rate ± Migration.

Factors influencing natural or vegetative growth

Health

A high standard of health care in a country will help reduce infant mortality, lowering the birth rate since people do not need to have as many children to ensure that some survive.

High standards of health care ensure that people have good access to modern medical treatment, which prolongs life expectancy and lowers the death rate.

In areas with healthy and balanced diets the mortality rate will decrease, but in countries with poor diets or lack of food the mortality rate will increase due to malnutrition. Countries with high standards of health care will have access to retrovirals, which gives them the potential to fight HIV.

Education

The emancipation of women reduces the birth rate, as women are able to obtain careers rather than stay at home and care for children which makes them less likely to have children.

Compulsory education ensures that people are educated about hygiene, venereal disease, and contraception. Knowledge of basic hygiene will decrease the mortality rate as people can maintain a better level of hygiene (assuming necessary items are available).

Education about contraception will help reduce the birth rate as people will be aware of the benefits of using contraception, but again this is dependent on the provision of contraceptives from governments or charities.

Very high levels of education provide an opportunity for advanced education, opening the way for the training of physicians and medical researchers, potentially reducing the death rate thanks to new discoveries and the availability of better-trained physicians.

Social security

If proper social care is provided to older adults and they are given proper medical care, the mortality rate is reduced as they are able to live longer.

If drinking water is available, the mortality rate is reduced, as waterborne diseases such as cholera are no longer common.

With an improved hygiene standard, the mortality rate is reduced. The availability of the media facilitates the education of people and awareness about disease outbreaks, potentially reducing the death rate.

The availability of the media is also essential to educate people about hygiene, avoiding illness, etc. if these people could not have formal education.

Cultural factors

In some cultures and religions, people are more respected if they have many children, resulting in an increase in the birth rate. For example, in some cultures having many children is seen as a sign of virility in men.

In contrast, some cultures and religions discourage large families, although this is rare. This would have the effect of reducing the birth rate. Certain religions view birth control and abortion as bad in the eyes of their beliefs.

As a result, they discourage the use of these procedures resulting in an increase in the birth rate in countries where these religions are prevalent.

In some non-secular countries, the use of contraception, and especially abortion, is prohibited, resulting in significantly higher birth and death rates as a result of the spread of sexually transmitted diseases.

Some religions and cultures relegate the role of women preventing them from obtaining an education or a career and are encouraged or forced to have large families, resulting in an increase in the birth rate.

Political factors

Some countries offer benefits to people who have many children to encourage people to give birth (eg France) as a result of an aging population. This has the desired effect of increasing the birth rate.

Alternatively, some countries offer rewards to couples who have fewer children in order to encourage people to have fewer children, resulting in a low birth rate.

If taxes in a country are high, people may not have children as they cannot afford it and this lowers the birth rate.

In times of war the birth rate will drop significantly and the death rate will often rise substantially. After a war, however, there is often a "baby boom" that results in a massive increase in the birth rate in a country.

Environmental factors

Countries with frequent natural disasters often have a high death rate. Also, there may be a large number of people who migrate out of the country out of fear for their lives, resulting in an overall reduction in the population of those countries.

Climate can affect death rates, in hot countries the death rate can increase due to the spread of diseases that spread more easily in hot climates.

In cold countries, the death rate can also be high due to the effects of cold and lack of supplies. In countries with heavy industry, air and water pollution could be very high, increasing the death rate as a result of contaminated water supplies.

References

1. Jackson, A. (2011). World Population Growth. 1-8-2017, from Geography AS Notes Website: geographyas.info.
2. World Health Organization. (2014). Natural population growth rate. 1-8-2017, from WHO Website: searo.who.int.
3. Kimball, J. (2012). Human Population Growth. 1-8-2017, from Kimball's Biology Pages Website: biology-pages.info.
4. Espenshade, T. (1975). The stable decomposition of the rate of natural increase. 1-8-2017, from Science Direct Website: sciencedirect.com.
5. Worldometers. (2017). Current World Population. 1-8-2017, from Dadax Website: worldometers.info.