An ecosystem is a functional ecological unit that
comprises of living organisms together with a non-living environment where
their interaction forms a system that is naturally self-supporting. The living organisms
form the biotic component while the non-living forms the abiotic components. It
is important to note that the abiotic provide food materials and energy in
order for the biotic to survive. An example of an ecosystem is the forest
ecosystem where there is a diversity of plants as well as animals. The
significant amount of rainfall in a forest leads to dense vegetation and the
trees grow very tall as they compete for sunlight whereas the animals shelter
under their canopies.
It is the abiotic component in the forest that
strongly influences the structure, behavior and the inter-relationships among
the living organisms. For instance, the soils comprise
of organic matter, rock sediments, mineral particles and living organisms and
it provides water, nutrients and a home to those organisms. The atmosphere is
another abiotic component that ensures supply of carbon dioxide for
photosynthesis and oxygen for respiration of the forest trees. Water circulates
between the atmosphere and the earth through processes such as evaporation,
precipitation, and transpiration. The
heat from the sun is important so as to heat,
evaporate and transpire water back to the atmosphere. Light from the sun is
necessary for the process of photosynthesis to take place. It is through
photosynthesis that the forest trees get the energy for their growth and metabolism.
Precipitation ensures water availability to the plants and this provides a
medium by which important minerals enter and get trans-located up in the plant.
Both plants and animals get their water from the surface of the earth and soil.
The biotic component in a forest ecosystem comprises
majorly the plants, animals, bacteria and fungi. An example of a plant species
in the forest is the mahogany and the animal species in the forest may include
lions, hyenas, deer and rabbits. Plants are classified as producers because
they are able to make their own food by using chlorophyll to trap sun energy
and convert it into carbohydrates using water and carbon dioxide. This process is
called photosynthesis and the energy is used by the plants for growth as the
rest is stored for future use. The animals in the forest fall under the consumer
category since they depend on plants for their food. Those animals that feed on
plants only are called herbivores, example rabbit. Other animals such as foxes
and snakes feed on herbivores and we call them primary carnivores or secondary
consumers. Tertiary consumers are large consumers such as wolves and feed on
secondary consumers. The last class of consumers is that of the lions and
tigers which feed on the tertiary consumers and are not eaten by any other
animal. The role of decomposers is to feed on dead organic matter for their own
food. These different levels of feeding can be summarized by the following food
Plant- Deer- Lion- Coyote- Decomposer.
Carbon is a crucial component in proteins and
carbohydrates and so it is important to understand the carbon cycle. Carbon
cycle refers to stages where carbon is gets incorporated into plants atmosphere
and transferred to consumers by eating. Carbon is emitted to the air either through
combustion of fossil fuels or respiration by animals and decomposers. Carbon
from air enters the plants through photosynthesis and to consumers by feeding
on the plants. The decomposers that feed on dead plants and animals also
release carbon to the atmosphere and process continues (Cox, 2010).
There exist different interactions in the forest
such as completion and predation whereby trees in the forest tend to grow tall
as they compete amongst themselves for sunlight while large consumers like lion
feed on primary consumers such as a gazelle. Invasive species such as plant
pathogens destroy the roots of plants causing wilt diseases which may lead to
reduced flow of water to the other plant parts hence reducing the carbohydrate
reserves. Forest services should therefore conduct extensive research to
determine the harmful pathogens and take appropriate measures to eradicate
Cox, P. M., Betts, R.
A., Jones, C. D., Spall, S. A., & Totterdell, I. J. (2000). Acceleration of
global warming due to carbon-cycle feedbacks in a coupled climate model. Nature, 408(6809), 184.