In a remote village in Kenya, members of two ethnic communities are on the verge of war. This war is not at all politically motivated but the reason is that one community, which is generally made up pastoralists, has invaded the farms of the other tribe and used their wheat fields for pasture. The pastoralists claim that there is no more grass on their fields to graze their livestock and cannot just sit and see them die of hunger. The rivers where they grazed their animals are drying up and an urgent solution must be found. This occurrence has been caused by the population increase of livestock and people in that area.
The Global human population rate peaked in the early sixties and since that time the number of human beings on earth and who share necessary resources such as food and water, went up and has grown by over seventy five percent since that time. By this year, it is estimated that the population of the earth is approximately seven billion people (West, 2009). High human population growth will definitely affects the ecosystem. This essay seeks to examine ecology in terms of population growth and human activities on the environment.
The greatest agent of the population growth is births. This means that the population increases when the number of the births is more than those of deaths. A small population that is introduced into the environment that has resources in abundance grows exponentially (Smith, 2008). However, as the population continues increasing, it reaches at the extreme limits of the recourses and its number starts moving down or just remains at a constant. This may happen because of competition between or amongst the species, or they may encounter a catastrophic event like disease or drought. Populations that experience exponential growth cycles will produce many young ones or seeds.
They have less food reserves, live for a short time, disperse rapidly and they are also in a position to colonize environments that are harsh and disturbed. There are those that grow exponentially at first, and then slow down in number as the population continues increasing. However, they maintain an equilibrium between their number and the resources available (Smith, 2008).
The major factors that influence the growth of the population include several population interactions which bind the community closer. They are competition between different species and also within individuals; predation which includes adaptation and predation. Competition is manifest especially in the situation where the organisms are many but the resources are scarce. For the majority of people and animals, they coexist sharing resources that allow them to survive to the adult age and/or reproduce. However for others, it is only the dominant species that access the scarce resources meaning that the others may get themselves lacking the necessities thus loose vigor or die (Smith, 2008). For animals, there is an organized structure; that resources are allocated to the species that are dominant excluding those that are subdominant.
The dominant species may occupy territories that they defend and push the subdominant ones to poorer areas. Competition is what brings out different species dividing resources in a community. On the other hand, predation as part of the interaction is where a living plant or animal consume one another. This is done to move nutrients and energy in to the ecosystem as well as removing those that are unfit. Parasitism is the condition where organisms live together but it is only one that benefits by drawing nourishment from the other. The parasite gains while the host looses. Parasitism and predation control and lower the population of some organisms (Smith, 2008).
The environmentalists have unanimously agreed that the majority of the problems that are related to the environments such as climatic changes, loss of some species and also the overuse of the natural resources are caused or intensified by the growth in the human population (West, 2009). Robert Engelman who works for Population Action International once stated
Trends such as the loss of half of the planet’s forests, the depletion of most of its major fisheries, and the alteration of its atmosphere and climate are closely related to the fact that human population expanded from mere millions in prehistoric times to over six billion today (West, 2009).
The first environmental impact that is caused by population growth is the loss of forests. Since the year 1950 over eighty percent of the world’s rainforests have already been cleared. This means that some of the animal and plant species that had their homes in these forests were lost. The loss of the forests has also been a major cause of global warming. This is due to the increase of the green house gases in the earth’s atmosphere.
Trees are very essential in the consumption and the storage of Carbon dioxide which is one of these gases (West, 2009). Population growth also leads to the presence of more mouths that need to be fed, more clothes to be worn, more houses to be built, and more factories to be constructed among others. This would mean that resources would be drained at a higher rate. For example the American population consumes about twenty five percent of all the world resources though they represent only four percent of the global population. Animals are being eaten at a high rate, fish harvested until their numbers are reducing by the overgrowing population. The other effect of the population on the environment is increased air, water and land pollution as more gases, company and household wastes are released into the environment (West, 2009).
This has caused the death of so many organisms in the ecosystem. Sammul (2003) however states that human beings manage the environment in a way that it becomes comfortable to them and not largely considering the other species. However sometimes the condition of the other species including their status and needs is considered. He continues to say that enough information has not being found on how the activities of man (which are for the protection of species and their habitats) influence the functioning dynamics of the populations and the ecosystems (Sammul, 2003).
References
Sammul, M. (2003). Effects of the human activities. Web.
Smith, R. L. (2008). Ecology. Microsoft Encarta. Web.
West, L. (2008). How global population growth is creating serious environmental problems. The New Times Company. Web.