An ecosystem can be defined as a biological environment comprising both living and non-living materials. The living elements include plants, microorganisms, birds, people and animals. The non-living things include rocks, minerals, soil, the surrounding atmosphere and water resources. An ecological system can be a lake, a game park or an entire tropical rainy forest. Ecosystems vary in size and elements that comprise them. It is complete, self-sustaining habitats, where the elements present inter dependence on one another for survival. Interferences with any part of the ecosystem would bin one way or another have an effect on everything else (George, Mokma, Hetherington & Michigan State University 1973).
An ecosystem, for instance a tropical forest in a terrestrial ecosystem, comprises of two main components, namely, biotic, which comprises living things and a biotic, which comprises of non-living things that is physical and chemical factors. Organisms that comprise the biotic component of a terrestrial ecosystem can be classified as heterotrophs and autotrophs, based on how they obtain their food for survival. Autotrophs are organisms that manufacture their own food from simple inorganic compounds in the environment. They make their own food through a process known as photosynthesis. The plants convert carbon dioxide and water in the presence of sunlight energy to carbohydrates and oxygen. Additionally, other producers like bacteria that can convert inorganic compounds from the environment to nutrients without sunlight. This process is known as chemosynthesis. Heterotrophs are organisms that cannot manufacture their own food from the environment. They get their nutrients from feeding on tissues of autotrophs and other consumers. The consumers form different classes depending on their source of food. Primary consumers that feed directly on plants, carnivores that feed on primary consumers, tertiary consumers like scavengers that feed on animal-eating animals and lastly omnivores that feed on both plants and animals, such as human (George, Mokma, Hetherington & Michigan State University 1973).
A complete ecosystem has all these species of organisms that exhibit interdependency for their survival. The species found in an ecosystem include native species that live and reproduce in and the ecosystem, immigrant species that have deliberately migrated or have been moved to an ecosystem by human beings. Indicators species, that indicate whether an ecological system is being degraded, and lastly keystone species that perform a role that affects the other cohabiting organisms (Schulze & Zwo%u0308lfer 1987).
The species in the ecosystem interact through the following ways; competition, which involves the cohabiting organisms to fight for the limited space, food, water and shelter. Through predation, this involves an organism referred to as a predator, which hunts the prey for food. Parasitism occurs, when a parasite that depends on other organisms for food and shelter. The other form of interaction is through mutualism that involves both organisms cohabiting generally benefiting from their interaction (Schulze & Zwo%u0308lfer 1987).
In an ecosystem, various cycles occur to facilitate survival of all the organisms. Nutrients, which are essential chemicals to life, move from the ecosystem, through organisms, and back to the ecosystem in a process called a biochemical cycle. Carbon dioxide is eliminated from animals and human beings to the environment and takes in oxygen for respiration. The plants through photosynthesis use the carbon dioxide to manufacture their food and release oxygen used by animals and human beings to breath. This process is called the carbon cycle. Through the nitrogen, cycle unused nitrogen is converted to useful nitrogen to plants like legumes. These cycles are essential in the survival of both plants and animals.
It is important to note, that they are cycles that are threatened by man’s day-to-day activities. For instance, human beings pollute the environment by releasing industrial gases and metals that affect the cycle processes, since there is more carbon gas and the plants that are not able to absorb all the emissions, therefore, causing global warming, which threatens the life vegetation. In case the vegetation is destroyed, most of the animals in the terrestrial ecosystem would perish. Human beings also threaten their survivals and survival of other animals by cutting down vegetation. By cutting down trees, deserts are created and habitats for the animals are destroyed. The water availability is also threatened, since the water catchments areas are destroyed. Lack of water would affect both the terrestrials and aquatic organisms (Muller 2010).
Through the study of components and functioning of an ecosystem, human beings are able to understand the role played by each organisms and its importance for the survival of the other organisms (Waring & Running 1998). Understanding of the biochemical, nitrogen, carbon and phosphorus cycles helps us manage the environment better through formulating policies that would help protect the environment. We can conclude that, decisive of the ecosystems would greatly influence the way we manage our environment for survival of all the organisms habiting and the non-living things too. Additionally, it is essential to note that interaction of the various species in an ecosystem is vital for their survival in general.