3.5 Population size and ecosystems Flashcards
What does population mean?
a group of individuals of the same species living in the same geographical area
What are the characteristics of a fugitive species?
poor at competition
Rely on captivity for reproduction
invade new environments rapidly
live in extreme environments
What are the characteristics of an equilibrium species?
Control population within a stable habitat
grow in a sigmoid curve pattern
What are the stage of the sigmoid curve?
Lag, Log, Stationary, Death
What does biotic mean?
Biological factors
What does abiotic factors mean?
Non biological fctors
What are some examples of biotic factors?
Predication, Parasites and disease, Cross species competition
What are some examples of abiotic factors?
Light
temperature
humidity
soil composition
oxygen availability
What does density dependent mean?
Targets one species
What does density independent mean?
Affects all organisms regardless of species
What does environmental resistance mean?
Factors that slow population growth
What does carrying capacity mean?
The max number around which a population fluctuates in a given environment
What does biogeography mean?
the study of an abundance of species
What does abundance mean?
the number of individuals in a species in a given area or volume
What are the steps in the mark and recapture method? (4)
- capture a group of a species in a given area
- mark the organisms ethically
- release them
- capture a second group after a given time
What conditions are required for the capture recapture method?
Sufficient time between capture
habitat undisturbed
marking must be uninhibition
What does ecosystem mean?
A biological community of interacting organisms and their physical environment
What does community mean?
An interacting group of various species in a common location
What is a pyramid of numbers?
A graph of the number of organisms at each trophic level
What is a pyramid of biomass
The biomass at each trophic level
What does productivity mean?
The rate of biomass production
How is energy lost through trophic levels?
Respiration
Egestion through faeces
Locked in undigested material (bones, fur ect.)
What is the formula for the photosynthetic efficiency?
E= Quantity of light incorporated / quantity of light available X 100
What is primary productivity?
The rate at which a consumer converts energy to biomass
What is secondary productivity?
The rate at which consumers accumulate energy from assimilated food in biomass in their cells and tissues
What is GPP?
Gross primary productivity
the energy not used in respiration
What are the limits of the pyramid of biomass?
No account for age
hard to measure dry mass
No energy flow indicated
Not all biomass transfers across trophic levels
What is a Sere?
The sequence of communities that from in primary or secondary succession after a habitat is created
What is a disclimax?
Stable community replacing a climax community
What do plants compete for?
Light, space, nutrients, soil, water
What do animals compete for?
Food, territory, water, mates
What are intraspecific conditions?
density dependent and between the same species
What are interspecific conditions?
Different species
all integrations between biotic and abiotic conditions
What is a Niche?
The role of a species within an ecosystem, specific to each species
What is commensalism?
Where 1 organism benefits and the other is not harmed
Symbiosis definition?
Long term interactions of 2 species
facilitation defintion
interactions that benefit at least 1 species
How is carbon fixed into organisms?
During photosynthesis
How is carbon released into the atmosphere?
Respiration
Combustion
How is carbon transferred?
decomposition
assimilation
sedementation
What 3 factors are impacting the carbon cycles balance?
deforestation
large scale combustion of fossil fuels
decomposition
How is nitrogen fixed from the atmosphere?
Nitrogen fixing bacteria (Like Rhizobium) convert N2 gas to ammonia in plants
How is nitrogen transferred into the soil?
Saprobotic bacteria decomposes plants releasing ammonium ions
What occurs in nitrification?
Nitrosomas convert ammonia to nitriles
Nitrobacter convert nitriles to nitrates
How is nitrogen released back into the atmosphere?
Under anaerobic conditions denitrifying bacteria converts nitrate to nitrogen gas
