ecology Flashcards
DEFINITION OF ECOLOGY
Ecology - is the scientific study of the interactions between different organisms and between organisms and their environment or surroundings
ECOSYSTEM
Ecosystem – is a group of living and nonliving organisms, which function together as a unit.
ECOLOGICAL FACTORS
1.biotic FACTORS
2.Abiotic factors
Biotic factors
they are living components in an ecosystem.
Abiotic factors
they are non-living, physical components in an ecosystem.
SOME INSTRUMENTS USED IN ECOLOGICAL STUDIES AND THEIR USES
✓ Wind vane – wind direction
✓ Anemometer – wind speed
✓ Hygrometer – Relative humidity
✓ Rain gauge – Rainfall
examples of Biotic factors
plants
animals
protists
fungi
bacteria.
examples of Abiotic factors
- sunlight,
- air,
- water,
- temperature,
- and mineral
photosynthesis
Photosynthesis - the use of light energy (sunlight) to convert carbon dioxide and warer into glucose and oxygen. E.g., plants
Chemosynthesis
Chemosynthesis - the use of chemical energy to produce glucose. E.g., bacteria
DIFFERENCE BETWEEN PHOTOSYNTHESIS AND CHEMOSYNTHESIS
– photosynthesis uses light energy (sunlight) while chemosynthesis uses chemical energy.
RAW MATERIALS REQUIRED FOR PHOTOSYNTHESI
Carbon dioxide and water
PRODUCTS of phosynthesis
Glucose and oxygen
CONDITION NECESSARY FOR PHOTOSYNTHESIS
Carbon dioxide,
water,
sunlight
and chlorophyll.
Autotrophs or Producers
autotrophs or producers are organisms that uses energy from sun (light) or other chemicals to produce their own food.
Heterotrophs or Consumers
these are organisms which derives their nutrients, energy, and food from eating other organisms
Decomposers
– these are fungus or bacteria, that feed on and break down dead plant or animal matter, thus making organic nutrients available to the ecosystem
TYPES OF CONSUMERS
Herbivores
Herbivores
Omnivores
Herbivores
organisms that feed only on plants.
Carnivores
organisms that feed only on animals.
Omnivores
organisms that feed on both plants and animals.
FOOD CHAIN
Food chain – is the feeding relationship in which energy is transferred from plants through series of organisms, with each stage feeding on the preceding stage and proving food for the succeeding one
Example of a food chain
a food chain in aquatic habitat: Algae → tilapia → cat fish
a food chain in terestrial habitat: Grass → grasshopper → toad → snake
the arrow shows the direction in which the food is being transferred.
Food web
is a complex feeding relationship among organisms in the same environment, with two or more interrelated food chains.
DIFFERENCES BETWEEN FOOD CHAIN AND FOOD WEB
No
Foodchain Food web
1
Food chain is a linear feeding relationship.
Food web is a complex feeding relationship.
2
It involves one food chain.
It involves two or more food chains.
3 It involves fewer organisms|.
It involves many organisms. |
4
Organisms have lesser chance of survival.
Organisms have greater chance of survival
Trophic level 0r energy level
Trophic level - is the feeding level or each stage in a food chain or food web
various trophic levels
Level 1 - Producers (autotrophs)
✓ Level 2 - Primary Consumers (herbivores)
✓ Level 3 - Secondary Consumers (carnivores or omnivores)
✓ Level 4 - Tertiary Consumers (carnivores - usually top carnivores)
Primary consumers
they are herbivores that feed only on plant or primary producers.
Secondary consumers
they are carnivores or omnivores that feed on herbivores or primary consumers.
Tertiary consumers
they are animals that obtain their nutrient by eating primary consumers and secondary consumers.
describe ENERGY FLOW IN AN ECOSYSTEM
green plants us chlorophyll in their leaves to trap energy from the sun to prepare their food during photosynthesis. Energy from the sun is stored in the food that green plants prepare. As herbivores eat the plant, the energy stored in the plant is transferred to the herbivores.
The herbivores transfer the energy to carnivores that are secondary consumers as the herbivores are fed upon by the carnivores. The energy in the carnivores is transferred to tertiary consumers when the tertiary consumers feed upon the secondary consumers.
ECOLOGICAL PYRAMID
Ecological pyramid – is a diagram that shows the relative amount of energy or organisms contained within each trophic level of an ecosystem
ENERGY PYRAMID
Energy Pyramid - shows relative amount of energy available within each trophic level of an ecosystem.
WHAT IS THE 10 PERCENT LAW OF ENERGY FLOW?
The 10 percent law of energy flow states that when energy is passed on from one trophic level to another, only 10 percent of the energy is passed on to the next trophic level.
BIOMASS PYRAMID
Biomass Pyramid - represents the amount of living biomass or organic matter at each trophic level of an ecosystem
BIOMAGNIFICATION
Biomagnification – the accumulation of a particular substance in the body of the organisms at different trophic levels of a food chain.
examples of Biomagnification
The accumulation of insecticide DDT which gets accumulated in zooplanktons. Small fishes consume theses zooplanktons. Small fishes are consumed by large fish which are finally consumed by fish-eating birds present at the highest position in trophic level. Hence, the organism at the highest trophic level has the maximum of toxic substances
Dichlorodiphenyltrichloroethane (DDT) Dichlorodiphenyltrichloroethane (DDT) is an insecticide used in agriculture
COMPETITION
Competition – is an interaction between organisms of the same or different species in which both compete or require a resource that is in limited supply
REASONS FOR COMPETITION AMONG PLANTS
✓ Inadequate light
✓ Inadequate space
✓ Inadequate nutrition
✓ Inadequate water
REASONS FOR COMPETITION AMONG ANIMALS
✓ Inadequate food ✓ Inadequate space ✓ Inadequate mates
TYPES OF COMPETITION
1 Intraspecific competition
2 Interspecific competition
Intraspecific competition
competition between organisms of the same species.
Examples
Two male deer competing for mates.
* Two oak trees growing too close together competing for sunlight and nutrition.
Interspecific competition
competition between organisms of different species
Examples * Herd of cattle and a herd of antelopes on a grazing land.
Iroko tree and terminalia in a forest competing for light
.Mango plants and grasses
HABITAT
Habitat – is a particular area within an environment where an organism can successfully live and it is the natural dwelling place of an organism
Ecological niche
the ecological niche involves both the place where an organism lives and the roles that an organism has in its habitat.
example of Ecological niche
The ecological niche of a sunflower growing in the backyard includes absorbing light, water and nutrients (for photosynthesis), providing shelter and food for other organisms
If the niche of two species is very similar, they might compete for food or other resources. Such as space, light etc.
DIFFERENCE BETWEEN HABITAT AND NICHE
a habitat is the place where an organism lives while a niche is that organism’s role within that environment
BIOLOGICAL ASSOCIATIONS
Symbiosis
Mutualism
Parasitism
Commensalism
Predation
Symbiosis
Symbiosis – is a close ecological relationship between two different species in nature.
Mutualism
Mutualism – is a close relationship between two organisms of different species in which both partners benefit
Examples
hermit crab and sea anemone
flowers and insects
alga and fungus in lichen
bacteria in the rumen of ruminants
, human and intestinal bacteria etc
Parasitism
Parasitism – is a close relationship between two organisms, in which one, the parasite, live in or on the body of the other, the host, deriving benefit from it and causing harm to it
Examples – human and a tapeworm
, human and mosquitoes,
fleas on dogs, etc
Commensalism
Commensalism - is a close relationship between two organisms of different species which is beneficial to one (commensal) but does not affect the other, the host
Examples – remora fish and shark
, oyster and crab
, barnacles on a whale, etc.
Predation
Predation – is a biological association involving an organism killing and feeding on other organisms
Examples – lion and goat, hawk and chicks of domestic fowls
Predator
Predator – an animal that kills and feeds on other animals
Prey
Prey – an animal that a predator eats or preyed upon.
Environment
Environment – is the living and the nonliving factors in the surroundings that affects the organism
Population
Population – is a group of organisms of the same species, in the same place (at the same time), which can interbreed with each other.
Community
Community – refers to a population of different species living together in an ecosystem and interacting with each other.
POPULATION ECOLOGY
Population ecology – is the study of the population in relation to the environment
POPULATION DENSITY
Population density – is the number of individuals per unit area or volume in a population at a given time
Population dispersion
Population dispersion – is the pattern in which individuals in a population are dispersed in an area.
It is also known as population distribution
PATTERN OF DISPERSION
Pattern of dispersion – refers to how the individuals in a population are distributed in space at a given time.
types of PATTERNS OF DISPERSION
Uniform dispersion n – organisms are evenly spaced over the area they occupy
Clumped dispersion – organisms are clustered together in groups.
Random dispersion – organisms have an unpredictable distribution
MAIN FACTORS WHICH AFFECT THE SIZE OF POPULATION
Birth rate or natality – refers to the rate of given birth to new organisms
Death rate or mortality – refers to the rate at which organisms die in a habitat
Immigration – refers to the movement of organisms from different habitats into a new habitat.
Emigration – refers to the movement of organisms out of a particular habitat for settlement into a new habitat.
If the death rate is very low compared to the birth rate, the population will not reduce.
DEMOGRAPHY
Demography - is the study of the vital statistics of a population and how they change over time.
Demographers – scientists who study human population statistics
CARRYING CAPACITY
Carrying capacity – is the maximum population size of a species that a particular environment can “carry” or sustain or normally and consistently support in terms of resources.
FACTORS WHICH AFFECT CARRYING CAPACITY
✓ Food availability
✓ Habitat space
✓ Water supply
✓ Competition
✓ Extreme heat
✓ Drought
FACTORS THAT INCREASE CARRYING CAPACITY
✓ Increasing food production ✓ Eliminating competing organisms ✓ Controlling disease organisms
Read more on the above factors.
FACTORS THAT DECREASE CARRYING CAPACITY
✓ Natural disasters (Read more)
✓ Competitors
✓ Disease and parasite
✓ Weather
✓ Predators
Note: Read more on the above factors.
LIFE TABLE
Life table – is an age-specific summary of the survival pattern of a population. (Read more
