Populations/sustainability Flashcards
What is the definition of conservation
Active management and sustainable use of organisms
What is the definition of coppicing?
Cutting back trees or shrubs to ground level periodically to stimulate growth
What is the definition of grazing?
Method of feeding in which herbivores eat plants. This can cause stress on plant populations which is termed grazing pressure.
What is the definition of preservation?
Protecting organisms or the environment from damage/destruction. Keeping species how they were prior to human interference
What is the definition of sustainability?
The use of components of biological diversity at a rate that doesn’t lead to the long-term decline of biological diversity, this maintains its potential to meet the needs of present/future generations
What are the 2 types of competition?
Interspecific
Intraspecific
What is interspecific competition?
Between individuals of different species
Eg grey and red squirrels
Different birds
What is intraspecific competition?
Between individuals of the same species
Eg vultures competing over 1 carcass
Wildebeest hunted by lions and crocadiles
How many organisms can supply a niche at one time?
Only one at a time
Why is there nearly always more prey than predators?
Energy is lost at each trophic level so there is less energy for predators than there is for prey
Why do predators populations size increase after prey population increases?
Don’t reproduce immediately, takes time to reproduce
What are the 4 phases of the population growth curve?
Lag phase
Log phase
Stationary phase
Death phase
What happens in lag phase?
Delay in growth of the population before the group is established as individuals acclimatise to the new conditions
What happens in log phase?
The population reproduces rapidly while resources are available and conditions are favourable
What happens in stationary phase?
When the population reaches its maximum, resources become limited so growth stops and numbers stay the same. Can fluctuate around carrying capacity. Reproduction rate = mortality rate, habitat can’t support a larger population
What happens in death phase?
Sometimes members of the population begin to die if toxic waste products build up (not always present)
What is carrying capacity denoted as?
K
What is carrying capacity?
The maximum population size that can be maintained over a period of time in a particular habitat
What are limiting factors?
Factors that prevent the populations becoming huge
What are some examples of biotic limiting factors?
Food eg grass for herbivores Shelter eg a tree Nesting sites eg nests in trees Parasites eg fleas, nits Predators Competition for resources
What are some examples of abiotic limiting factors?
Light Conc of carbon dioxide Oxygen Water Food eg dead animals pH Temperature Nesting sites eg rabbits warren Shelter eg building
What are some examples of abiotic limiting factors?
Light Conc of carbon dioxide Oxygen Water Food eg dead animals pH Temperature Nesting sites eg rabbits warren Shelter eg building
What does density dependent mean?
As competition increases so does population size
What is an example of density independent limiting factor?
Temperature
