Chapter 5 - Ecosystems Flashcards
Feeding Levels (4)
Producers - Primary Consumers - Secondary Consumers - Decomposers
Producers
Organisms (usually plants) that convert some of the suns energy into stored chemical energy.
Primary Consumers
Herbivores. They obtain energy by consuming producers.
Secondary Consumers
Carnivores. The obtain energy by consuming primary consumers.
Decomposers
Organisms that obtain energy by breaking down dead organisms from the three other levels.
Energy Pyramid
Top - Secondary Consumers
Middle - Primary Consumers
Bottom - Producers
Conservation
Only a small amount of energy is passed on to the next level. E.g. in a leaf, not all the suns energy makes it into the leaf. Remaining energy will be lost in many ways (heat) energy that is left over becomes available to the next feeding level when the plant is eaten.
Food Chain
A feeding hierarchy in which organisms in an ecosystem are grouped into trophic (nutritional) levels and are shown in a succession to represent the flow of food energy and the feeding relationships between them.
Food Chain Example
- Plant - Producer
- Insect - Herbivore/ Primary consumer
- Mouse - Omnivore/ Secondary Consumer
- Hawk - Carnivore/ Tertiary Consumer
Food Web
The best way to model a feeding relationship. More elaborate that single unbranched chains.
Carrying Capacity
The maximum number of organisms that a particular environment can support over time.
Lag Phase
Population size grows very slowly, and organisms mature and adapt to the environment.
Exponential Phase
With plentiful food, the population will grow quickly.
Stationary Phase
When the population size outgrows the amount of available food, growth will begin to plateau.
Limiting Factors (6)
Food Available Births Deaths Number Coming In Number Moving Elsewhere Competition
Predator - Prey Relationship
A relationship in which one organisms feeds on another.
Symbiosis
Interaction between two different organisms living in close physical association.
Symbiosis Types (3)
Parasitism
Mutualism
Commensalism
Parasitism
Relationship in which one organism (parasite) benefits whilst the other (host) is harmed.
Example - Tapeworm living in the intestines of a cat. Tick living on a dog.
Mutualism
Relationship in which both species benefit.
Example - Ants living in and protecting an acacia tree. Clown fish living among sea anemones.
Commensalism
Relationship in which one species benefits and the other is neither harmed nor benefited.
Example - Hermit crabs using gastropod shells for shelter. Spiders building webs on plants.
Disruption Examples (4)
Flooding
Habitat Destruction
Desertification
Invasive Species
Flooding
An overflow of water covers land not normally covered in water. Ecosystems of water based habitats are also impacted by runoff containing sediments and pollutants.
Habitat Destruction
Natural habitat is displaced or destroyed and is not able to support the species present. Human activity such as urban sprawl, mining, drilling, logging and deforestation for farmland are the principle causes.
Desertification
Relatively dry land regions become increasingly arid. Bodies of water being to dry up, causing loss of plant and animal life. Primarily caused by climate change and human activities like deforestation.
Invasive Species
When non-native species that adversely affect the habitats and ecology of an area are introduces to an area. Species such as plants or animals may disrupt ecosystems by outcompeting the native species for limited resources such as food and space.
Succession - Definition
Gradual and orderly process of change in an ecosystem brought about by progressive replacement.
Succession - Example
Annual Plants - Perennial Plants & Grasses - Shrubs - Young Pine Forrest - Mature Deciduous Forest.
Extinction
The disappearance of a species when the last of its members have died.
Reasons For Extinction
Natural Process
Hunting
Urbanisation
Destruction of Forests
