Some other factors that arise human activity & influence the ecology of organisms. These are Pollutants.

These are termed Anthropogenic Environment Factors. ( Negative effects for living organisms.) 
 

Natural Environment Factors


Mainly grouped into 3 categories,
  1. Edaphic factors
  2. Climatic factors
  3. Topographic factors
The physical environment of an organism depends on the organism's Location( Latitude & Altitude), topography(landscape), geology(rocks & soil types) climate, weather, and catastrophes (fire, earthquakes).

The geology and topography are different in different places on earth.

Atmospheric factors,

  • Humidity
  • Wind speed
  • Temperature
  • Sunlight
  • Rainfall 
  • Availability of water 
(These factors will change during the day)

Topography


The arrangement of the natural and artificial physical features of an area is known as topography.
Topography depends on the structure of the earth, presence, and distribution of rocks, soil, and sediment.

Aspects of the direction of the sun land facing are also important to the distribution of plants and animals.

Soil and Sediment


Different rock types and soil form the geology of an area. They are the product of many long and complicated processes. 
  • Included the movement of continents by plate tectonics.
  • Igneous activities such as volcanoes- form igneous rock.
The soil texture and soil structure determine the soil moisture content and soil air content.
The soil provides a medium for life. It's stable both chemically and structurally.
Nutrients collect in the sediment. Sediments are also the rooting medium for aquatic plants & burrowing animals.

Light


Plant fix the energy of sunlight through the process of photosynthesis.
Animals depend on light for orientation and diurnal migration.
Animals have light receptors,
  • Vertebrate eyes
  • Compound eyes
  • Simple eyes or ocelli
In the aquatic environment, the intensity of light is less when compared to the land environment because about 10% of light is lost due to reflection at the surface of the water.
The phytoplankton, zooplankton, and suspended organic and inorganic particles reflect or absorb the light rays.
The longer light rays are absorbed near the surface & the shortest light rays penetrate the deepest.
Sunlight is a component of electromagnetic radiation. Sunlight contains radiations with the frequency of wavelength ranging from 390nm - 700nm.
The autotrophs get their primary energy from this visible light and the radiant energy is converted to chemical energy during photosynthesis. 

Temperature


The solar radiation that reaches the earth's surface causes heating of soil, water, vegetation. It's measured as temperature.
Enzymes are destroyed at high temperatures or at low temperatures.
The temperature varies daily and seasonally.
Low latitudes of the world receive more heat compared to polar regions.

Temperature variation with the depth of water.

Winter

  • Temperature falls
  • Surface water is cold nearly to the freezing point (0℃) from ice.
  • Below this layer the temperature is 2℃ - 4℃ down to the bottom
  • The ice that forms is less dense than the water and floats on the surface of the water(Thus enabling the aquatic organisms to survive during the cold period without freezing).

Summer

  • Temperature about 22℃ on the surface.
  • It decreased gradually towards the bottom (7℃)
  • The results of that create a stratification of the water body, thus creating different layers of water.
  1. Epilimnion - warm surface layer
  2. Hypolimnion - colder bottom layer
  3. Thermocline - sharp changes in temperature

Humidity


Water evaporates from the aquatic habitats by solar radiation forming water vapour and adds on to the air. Plants also lose an amount of water during transpiration.

The invisible water vapour that adds to the atmosphere, That condition known as the Humidity of the air. Sometimes water vapour present in the air is also called the "moisture of the air".

  • Oceans, seas, lakes and rivers provide 90% of the moisture in the atmosphere via evaporation.
  • The remaining 10% is contributed by plant transpiration.
Humidity is explained by various definitions,
  • Absolute humidity - the mass of water vapour in a given volume of air.
  • Specific humidity - the mass of water vapour per unit mass of air.
  • Relative humidity - is expressed as a percentage. the ratio of the amount of water vapour actually present in the air to the greatest amount possible at the same temperature.