An ecosystem may be defined as a system that includes all living organisms in an area as well as the physical environment functioning together as a unit. An ecosystem may be very large, for example an entire rainforest. An ecosystem may also be very small, for example a pond.
Components of an Ecosystem
An ecosystem is made up of living and non-living components
Living (biotic) components: This includes all organisms in an ecosystem including plants and animals from the very large to the microscopic. The living components of an ecosystem can be further subdivided into the following groups:
- Producers: These are green plants which make organic compounds from simple inorganic molecules in a process called photosynthesis. In simpler terms, they use carbon dioxide, water and sunlight to make food. A green substance known as chlorophyll enables them to do this. There are many types of producers, from the largest trees in the rainforest to microscopic algae. All other organisms in an ecosystem are dependent on producers either directly or indirectly.
- Primary consumers: These are organisms which obtain their nutrients directly from plants. They are also known as herbivores. Examples of primary consumers include grasshoppers, goats and zebras.
- Secondary consumers: These are organisms which feed on other animals. A lion is a secondary consumer as it eats animals such as zebras. Lizards, wolves and hawks are also examples of secondary consumers.
- Decomposers: These are organisms which feed on and break down dead organic matter. Decomposers break down dead plants and animals into simpler substances which can be absorbed by producers such as plants and algae. They include bacteria, fungi and earthworms.
Non-living (abiotic) components: These components include sunlight, temperature, water and soil. These components play an important role in determining the types of ecosystems which develop in particular areas.
Climate, Soil and Ecosystems
There are many different types of ecosystem. Climate plays a major role in determining the type of ecosystem which develops in an area. The amount of rainfall experienced annually in an area will affect the types of plants and animals which can survive there. For instance, in an area which experiences very little rainfall, you will only find plants and animals which are able to survive in the dry conditions. Temperature is also an important factor in determining the type of ecosystem which develops in an area. In areas which are very cold you will find plants and animals which are adapted to survive in low temperatures. Similarly, in areas which are very hot you will find organisms which are adapted to survive in high temperatures. Therefore, when studying an ecosystem, it is important to acknowledge the influence of the climate.
Soil often plays a major role in the development of an ecosystem. Soil is composed of weathered material, organic matter, water and air. There are many types of soil. The type of soil which is found in an area is influenced greatly by the climate and also the type of rock which is weathered to produce the soil. The type of soil found in an area determines to a large extent the types of plants which can grow there. This in turn influences the types of animals which can survive there.
The CXC/CSEC Geography syllabus requires students to study the climate, soil and vegetation found in equatorial and tropical marine regions. In simpler terms, you are expected to study the ecosystems which develop in these areas.
The video below briefly outlines the concept of an ecosystem.