The Soil or Edaphic Factors
The edaphic factors are the abiotic factors that affect the. These factors are subdivided into:
• Soil texture – The texture of the soil varies and depends on particles like clay to larger particles like sand. Sandy soils are suitable for growing plants and are well aerated and are easy to cultivate. Sandy soils cannot keep hold of much water and has few nutrients required for plant growth.
• Soil air – Soil air is the spaces between the soil particles where it is not filled with soil water. The soil air in a particular soil sample determines its firmness.
• Temperature of soil – The temperature of the soil is a crucial factor, temperature of soil less than 30cm is said to be constant although there are seasonal variations. The decaying caused by decay-causing microorganisms is small at lower temperature.
• Soil water – Soil water can be divided into three types – capillary water, hygroscopic water and gravitational water.
• Soil pH – The pH of the soil affects the biological activity of the soil and a few mineral’s availability. The pH of soil affects the growth and development of plants.
• The organisms and the decaying material in the soil are referred to as soil solution and this increases the fertility of the soil.
Light is the primary source of energy to more or less all type of ecosystems. The light energy is made use of by the autotrophs to manufacture food by the process of photosynthesis with a combination of other inorganic substances.
The factors of light like its quality, intensity and the length or duration of light play a crucial role in an ecosystem.
• The quality of light affects the aquatic ecosystems environment, the blue and red light is mostly absorbed here and this does not penetrate deep into the water. Some algae have particular pigments that enable them to as well absorb the other colors of light.
• The intensity of light or light intensity depends on the latitude and the season of the year. During the period from March to September, the Southern Hemisphere receives below 12 hours of sunlight whereas it receives more than 12 hours of sunlight during the remaining part of the year.
• A number of plants flower merely during a specific time of the year.
One of the factors is as a result of the length of dark period. Depending on the intensity of light the plants are classified as short-day plants (Example Chrysanthemum sp., Datura stramonium etc.) Long-day plants (Examples – Spinach, barley, wheat, radish, clover, etc.) Day-neutral plants (Examples – Tomato, maize, etc.)
Temperature affects the distribution of plants and animals. The occurrence of frost is crucial to determining the distribution of plants as the majority of the plants cannot alter the freezing of their tissues. Below are some examples of the effects of temperature in plants and animals:
• The blooming of flowers either in the day or night is as a result of the temperature difference between day and night.
• Some biennial plants sprout during spring or summer and this is referred to as vernalization.
• Some fruit trees need cold temperature in order to blossom or produce flower in the spring time.
• Animals have a clear distinction between being cold blooded or warm blooded.
• Seasonal migration is observed in a few animals.
Habitats of animals and plants differ greatly. It could range from aquatic environments to the dry deserts. Water is an essential requirement for life and every biotic components of the ecosystem are directly dependent on water for their growth and survival.
Based on the water requirements of plants, they are classified as:
• Hydrophytes (Example – Water lilies)
• Mesophytes (Example – Sweet pea, roses)
• Xerophytes (Example – Cacti, succulent plants)
Land animals are prone to desiccation and these animals demonstrate different types of adaptations in order to prevent this from occurring. Some of the adaptations noticeable in terrestrial animals are:
• Body covering which reduces loss of water.
• A few animals possess sweat glands which are employed as cooling devices.
• The tissues of a few animals such as camel are tolerant to water loss.
• Some insects are known to absorb water from the water vapor directly from the atmosphere.
Air currents also known as winds are a result of interaction that exists between expansion of hot air and convection in the mid latitudes. This composite interaction affects the earth’s rotation and leads to a centrifugal force which lifts the air at the equator. Some of the consequences of wind are:
• Winds as well carry water vapor; which may undergo condensation and precipitate in the form of rainfall, hail or snow.
• It also assists in the dispersal of pollen grains of a few plants as well as in the dispersal of insects.
• Wind erosion as well leads to dispersal of topsoil.
Atmospheric gases are gases like oxygen, nitrogen and carbon dioxide:
• All organisms need oxygen for respiration.
• Carbon dioxide is utilized by green plants to manufacture food by the process of photosynthesis.
• Nitrogen is essential for all plants and atmospheric nitrogen is fixed by nitrogen fixing bacteria through the action of lightening.
Topography or shape of the land is the landscape shapes and is determined by the aspects of slopes and elevations. Topography gives diversity to the ecosystems. For instance: The grassland topography is made up of various forms like hills, prairies, cliffs, low lying areas and so on which offers variability to living organisms.
• The aspect of the direction of the land facing also varies as the land facing towards the south or the sun ar hotter and drier than areas in the north, which are away from the sun.
• Slope of on areas is as well crucial due to the fact that water may run downhill and may soak in ground which makes it accessible for plants. The areas in the southern part with slopes will be much hotter and drier than the northern areas with slopes.
Climate of a region involves the average rainfall, temperature and the patterns of winds that take place in that region. Climate is one of the most crucial abiotic factors of an ecosystem.
• Temperature of an area and the precipitation factor regulates the type of vegetation in the area like whether the region is grassland or a forest.
• The rainfall in an area affects the productivity of the area and the types of plants that would grow and thrive there. For instance: The climate in a grassland ecosystem is dry and hot during the spring and summer and is cool and cold during the winter.
• Precipitation in winter is snow instead of rainfall. During summers, more water is evaporated from the grasslands making the region deficient of moisture.