Climate & Climate Classification II SS2 Geography Lesson Note

SPHERES OF THE ENVIRONMENT

The Earth as an environment is grouped into four spheres:

1. Lithosphere: The solid portion of the environment which contains rocks, sand, soil, minerals etc.
2. Hydrosphere: This is the liquid portion of the environment like rivers, lakes and oceans.
3. Atmosphere: This is the gaseous portion of the environment where gasses like oxygen, nitrogen, carbon dioxide, and ozone are found.
4. Biosphere: This is the portion of the environment where plants and animals are found.  These four spheres of the environment are interrelated and interdependent.

Ecosystem: An ecosystem is defined as a community of plants and animals living together in harmony and interacting with their physical environment.

In other words; an ecosystem can be defined as the relationship that exists between living things and their nonliving environment.

COMPONENTS OF ECOSYSTEM

The ecosystem is made up of two main components.  These are:

1. Abiotic (non-living) component: These are the components like soil, water, gasses, sunlight etc in the environment.
2. Biotic component: This is the living component of the ecosystem.  It includes plants and animals.

Biotic components can be grouped into three (3)

a) Autotrophs: These are also called the producers.  They include the green plants which manufacture their food through a process known as photosynthesis.

b) Heterotrophs: These are called primary and secondary consumers.  These organisms cannot manufacture their food but depend directly or indirectly on plants for their food e.g. man, parasites, saprophytes.

c) Decomposers: These are microorganisms that decompose dead organic matter to release nutrients required by producers to prepare their food e.g. Fungi and bacteria holistically, the components of an ecosystem can be grouped into the following:

– Land (soil)

– Water (Lake, Oceans)

– Plants        

– Animals

– Drainage (river)

– Climate (Atmosphere)

INTERDEPENDENCE WITHIN THE ECOSYSTEM

Interdependence is the word used to describe the relationship between the components of the ecosystem.  This is because components in an ecosystem depend on one another and they cannot exist in isolation.  A state of interdependence within the ecosystem is best achieved where the components are undisturbed.

Interdependence in an ecosystem exists in three ways:

1. Interdependence within Abiotic components e.g. The weathering of rock to form soil or the evaporation of water to form clouds etc.
2. Interdependence within Abiotic components e.g. Animals depend on plants for food or the exchange of oxygen and carbon dioxide by plants and animals.
3.  Interdependence between the biotic and abiotic components e.g. plants depend on soil for support and nutrients, and Autotrophs convert sunlight, and energy.  Water and carbon dioxide during photosynthesis to produce food etc.

ENVIRONMENTAL BALANCE

Environmental balance refers to the ways of recycling matter and the flow of energy within an ecosystem to ensure continuous supply or availability.

Environmental balance is achieved through the following processes:

(i) Hydrological (water) cycle

(ii) Carbon cycle

(iii) Nitrogen cycle

(iv) Mineral nutrient cycle

(v) Food chain and food web. 

 ASSIGNMENT

1. The height of a place above the sea level is known as (a) Latitude (b) Altitude (c) Lapse rate (d) Spot height
2. Which of these factors does not affect weather and climate (a) Cloud cover (b) Humidity (c) Latitude (d) Natural Vegetation
3. The instrument used for measuring wind direction is(a) Wind vane (b) Thermometer(c) Anemometer (d) Rain gauge
4. Wet and dry bulb thermometers could be used for measuring (a) Rainfall (b) Relative humidity (c) Temperature (d) Wind speed
5. Which of the following weather elements is paired with the wrong instrument? (a) Wind direction and wind vane (b) Humidity and anemometer (c) Rainfall and rain gauge (d) Atmospheric pressure and barometer