exam 3 part 1 Flashcards
Biotic factors
living organisms that make up an ecosystem and interact with each other and their environment
Abiotic factors
nonliving parts of the environment that affect living organisms and ecosystems
Top-Down factors
the influence of a higher trophic level organism on the population of organisms at lower trophic levels
Top-down Regulation of Population Growth
Host-parasite relationships / Cyclic dynamics of red grouse and nematodes
Bottom-up factors
the pressures that limit the availability of resources to lower trophic levels in a food chain
exmaple: el nino and penguins
Density-Dependent Factor definition
affects the size of a population based on how dense that population is
Density-Dependent Factors learned about (4)
-Birth, death rates, carrying capacity
-Exploitative competition and population cycles
-Predation and population cycles
-Intraspecific competition
With constant (independent) birth rate, K is
at higher ρopulation
With constant (independent) death rate, K is
at lower ρopulation
With birth and death rates ρopoulation dependent, K is
balanced at medium ρopulation
Resilience
rate at which pop returns to equilibrium post disturbance
population Cycles usually limited to
simple ecosystems
Exploitative competition and population cycles (3)
-As a population increases, individuals exploit the shared resource more rapidly,
-leading to a decline in its availability for other individuals
-which can hinder their growth and reproduction.
Predation and population cycles
refers to the cyclical pattern where the population of a predator species rises and falls in direct response to the fluctuations in the population of its prey species
Intraspecific competition
when two or more individuals of the same species simultaneously demand use of a limited resource
