Ecological concept, Ecological factors, their effects on the ecosystem, and instrument use in measuring them.
Ecological concept, Ecological factors, their effects on the ecosystem, and instrument use in measuring them.
Ecological concept.
The biosphere is the area of the Earth (including sea, freshwater, and land) and the atmosphere where life exists
- Atmosphere: it is the layer of air that envelopes the Earth
- Hydrosphere: it is the part of the Earth composed of water
- Lithosphere: it is the rocky and soil part of the Earth
Environment: it consists of everything in the immediate surroundings of an organism, e.g., water, light, temperature, etc.
An ecosystem is a natural unit that is made up of both living and non-living things interacting together to produce a stable system
Habitat: it is a particular locality/specific place within an environment where an organism naturally lives successfully. E.g., pond, seashore, rainforest, freshwater, etc.
Population: it is the total number of individuals of the same species, living together in a particular habitat, e.g., a population of weaver birds living in a tree. OR A population is defined as all the organisms belonging to the same species within an area at the same time.
Community: it refers to all populations of different species of organisms, living together and interacting with one another in a habitat, e.g., termites, earthworms, and bacteria form a community in the soil.
Ecological niche: it is the exact place an organism lives, including its behaviour, feeding habits, and breeding habits
Dominant species: they are organisms whose population outnumbers other species in a community. The community is named after the dominant species. E.g., a cocoa tree community, a grassland community
Ecosystem: it is made up of all the living and non-living factors in a habitat, interacting together to produce a stable system. Examples of ecosystems include grassland, forest, pond, sea, etc.
Biome: it is a large natural area of an ecosystem with a particular climate, e.g., tropical rainforest, desert, etc.
ECOLOGICAL FACTORS
These are factors that affect the lives of organisms living in their habitat, development, distribution, and behaviour.
These factors can be:
- Abiotic factors
- Biotic factors
Abiotic factors
These are the non-living components of a habitat or ecosystem that affect the lives of organisms. Examples are
- Light
- Temperature
- Rainfall
- Humidity
- Wind
- Pressure
- Hydrogen ion concentration
- Degree of salinity
- Slope of land
- Altitude (height)
- Carbon (iv)oxide concentration
- Oxygen concentration
- Concentration of pollutants
- Turbidity and depth of water
Temperature
Temperature is the measure of the degree of coldness or hotness of a body or system.
Temperature is measured with a thermometer; however, the maximum-minimum thermometer is used to measure the highest and lowest temperatures. (In a day, week, or month).
It is measured in Degrees Celsius, Kelvin, or Degrees Fahrenheit.
An increase in the temperature in an ecosystem can be caused by;
- Poor ventilation
- Low altitude
- High intensity of sunlight.
- Warm ocean current
- Poor vegetation cover.
The low temperature in an ecosystem can be due to;
- Cold current from the ocean.
- Sunlight intensity, when it is low or there is shade.
- Well-ventilated and adequately circulated with cold air.
- Wet weather conditions, high humidity, or rain.
How temperature affects plants and animals in an ecosystem
- An increase in temperature increases the rate of metabolism in organisms
- An increase in temperature increases the rate of transpiration in plants
- An increase in temperature increases the growth rate of animals such as toads and houseflies
- Increase in decay in organic matter as temperature increases
- Evaporation of water in soil, rivers, and lakes also increases as the temperature rises
Rainfall
Rainfall is the precipitation of water as a liquid resulting from the condensation of warm clouds.
Rainfall is measured with a rain gauge
How rainfall affects plants and animals in an ecosystem
- It makes water available for plants
- Rainfall patterns affect the distribution of organisms
- Rainfall variations can result in drought or floods, which can destroy vegetation and animals
- Onset of rainfall induces winged termites to go on a nuptial flight
- Rainfall determines the salinity of aquatic habitats, which determines the distribution of organisms
- Rainfall affects the light intensity and affects the activities of organisms
- Rainfall affects temperature, which also affects the distribution and other activities of organisms
- The amount of rainfall can determine the level of soil erosion, which affects plant growth and destroys habitats
- The amount of rainfall affects humidity, which affects the transpiration
- Amount of rainfall affect turbidity(transparency)of water bodies which affect distribution of organism
- Rainfall provides breeding grounds for toads and frogs to lay their eggs
- Rainfall increases the turbidity of water and also causes soil erosion and leaching
Wind
The wind is the air in motion.
The speed of the wind is measured with an anemometer.
The direction of the wind is measured with a wind vane.
Effects of Wind on Plants and Animals in an Ecosystem
- It increases the rate of evaporation or transpiration/desiccation of organisms
- Strong wind causes soil erosion
- It serves as an agent of pollination
- It also serves as an agent of seed and fruit dispersal
- Strong winds may uproot or break off branches of plants
- Facilitate the spread of air-borne diseases
- Has the means of spreading bushfires
- Wind spreads pollutants in the ecosystem.
Altitude
It refers to the height of the land above sea level
How Altitude Affects Organisms
- As altitude increases, atmospheric pressure and oxygen level decrease, and breathing is affected
- Organisms at a higher altitude experience low temperatures and strong winds
- Altitude affects the distribution of organisms.
How animals are adapted to high altitudes
- Individuals have more red blood cells
- They develop larger ventricles to pump blood more efficiently
- They can also breathe fast
- Have a larger heart and chest
- Organisms that live at higher altitudes include eagles
Turbidity
Turbidity is the measure of the cloudiness or muddiness of a water body.
It is measured with a Secchi disc.
Turbidity affects the rate of photosynthesis of aquatic plants
It affects the vision of aquatic animals.
Atmospheric Pressure
It is the pressure exerted on objects on the Earth’s surface by the atmosphere
Atmospheric pressure is measured with a barometer
The atmospheric pressure increases with increasing depth and decreases with increasing altitude.
Light intensity:
Light intensity on land is measured by a photometer
In water, light intensity is measured with a light-intensity probe
Effects of Light on Organisms
- Termites swarm at night to avoid birds preying on them
- Humans can produce vitamin D through the actions of ultraviolet light rays on the skin cells
- Lights also affect the distribution of organisms in habitats
- Light affects the rate of photosynthesis of plants
- Light affects the vision of organisms and the movement or locomotion of organisms
Humidity
It is the measure of the moisture content of the atmosphere or the amount of water vapor in the atmosphere.
Humidity is measured with a wet and dry bulb hygrometer.
How humidity affects plants and animals
- Low humidity causes land-living organisms to lose more water from their body through evaporation
- An increase in humidity decreases transpiration in plants as leaf cuticles are covered
- High humidity also affects the activeness of cold-blooded animals, e.g., lizards
- Low humidity affects the wilting of plants.
Biotic Factors
These factors form the living components of a habitat. There is an interaction between organisms in many ways; some depend on others for food and shelter, some are also harmful to the community, and others are also useful.
Examples are:
- Food,
- Shelter,
- Mechanical support,
- Mating partners,
- Pollination,
- Grazing,
- Nitrogen fixation.
Ways in which biotic factors are carried out within the community
- Tall trees shelter shade-loving plants as well as animals
- Basically, herbivores feed on plants and may destroy them
- Carnivores eat other animals
- Insects and some birds pollinate flowers
- Many animals are agents of pollination
- Plants with weak stems use other plants for support for light
- Parasites live in or on the living host and may eventually cause their death
- Epiphytes grow on a living host, usually a tree, but do not cause any of it
- Activities of humans such as cutting trees, bush burning, clearing bushes to build houses, mining, etc.
Examples of harmful biotic factors include;
- parasitism,
- carnivores’ activities (Predation),
- cannibalism,
- and human activities.
Questions for revision.
- Explain the following;
- Population
- Habitat
- Ecosystem
- Biosphere
- Ecological niche
- List four ecological factors that are common to all habitats and state the instrument you will use to measure them.
- State four effects of each of the following factors on the ecosystem.
- Wind
- Rainfall
- Temperature
